EPA 550/9-76-004
NOISE EMISSION STANDARDS FOR CONSTRUCTION
EQUIPMENT
BACKGROUND DOCUMENT
FOR
PORTABLE AIR COMPRESSORS
December 1975
U.S. Environmental Protection Agency
Office of Noise Abatement and Control
Washington, D.C. 20460
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TECHNICAL REPORT DATA
(Please read Instructions on the reverse before completing}
1. REPORT NO.
EPA 550/9-76-004
2.
4. TITLE AND SUBTITLE
Noise Emission Standards for Construction
Equipment
Background Document for Portable Air Compresso:
7. AUTHOR(S)
9. PERFORMING ORGANIZATION NAME AND ADDRESS
Office of Noise Abatement and Control
U.S. Environmental Protection Agency
Washington, D.C. 20460
12. SPONSORING AGENCY NAME AND ADDRESS
15. SUPPLEMENTARY NOTES
3. RECIPIENT'S ACCESSION>NO.
5. REPORT DATE
Bee ember
1975
6. PERFORMING ORGANIZATION CODE
•s
8. PERFORMING ORGANIZATION REPORT NO.
1O. PROGRAM ELEMENT NO
11. CONTRACT/GRANT NO.
13. TYPE OF REPORT AND PERIOD COVERED
14. SPONSORING AGENCY CODE
16. ABSTRACT
This document contains the technical, economic, health and
welfare analyses and other pertinent data and information utilized
by the Environmental Protection Agency in the development of the
final Portable Air Compressors Regulation.
17.
I. DESCRIPTORS
KEY WORDS AND DOCUMENT ANALYSIS
b. IDENTIFIERS/OPEN ENDED TERMS
compliance costs, construction
equipment, enforcement, exposed
population, noise levels, portable
air compressors, regulations
18. DISTRIBUTION STATEMENT
Release unlimited
19. SECURITY CLASS (This Report)
2O. SECURITY CLASS (This page)
c. COSATI Field/Group
21. NO. OF PAGES
238
22. PRICE
EPA Form 222O-1 (S-73)
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EPA 550/9-76-004
NOISE EMISSION STANDARDS
FOR
CONSTRUCTION EQUIPMENT
BACKGROUND DOCUMENT
FOR
PORTABLE AIR COMPRESSORS
»
December 1975
This document has been approved for general availability.
It does not constitute a standard, specification or regulation.
U.S. Environmental Protection Agency
Office of Noise Abatement and Control
Washington, D.C. 20460
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TABLE OF CONTENTS
Section 1 PROLOGUE
Statutory Basis For Action
Preemption
Labeling
Imports
Section 2 RATIONALE FOR REGULATION OF THE PORTABLE
AIR COMPRESSOR
Identification of Major Sources
Construction Equipment
Section 3 BACKGROUND INFORMATION
Section 4 THE INDUSTRY AND THE PRODUCT
General Description
The Industry
The Product
Section 5 EXISTING LOCAL, STATE, AND FOREIGN NOISE
REGULATIONS
Local And State Regulations
Foreign Regulations
Section 6 MEASUREMENT METHODOLOGY
Measurement Standards
CAGI Method - Sound Pressure Level
.0-Point Hemisphere Method - Sound Power Level
National Bureau of Standards Methodology
Ln'A Portable Air Compressor Noise Test Procedure
Test Site Description
Measurement Equipment
Page
1-1
1-1
1-1
1-3
1-3
2-1
2-2
2-3
3-1
4-1
4-1
4-5
4-8
5-1
5-1
5-4
6-1
6-1
6-1
6-3
6-3
6-6
6-11
6-11
111
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TABLE OF CONTENTS (Cont)
Portable Air Compressor Operation
Test Conditions
Microphone Locations
Data Required
Calculation of Average Sound Levels
Presentation of Information
Section 7 PORTABLE AIR COMPRESSOR NOISE
Overhead Noise
Portable Air Compressor Noise Levels
New Data
Existing Data
Correlation of Data
Noise Directivity
Portable Air Compressor Sound Power Level
CAGI/PNEUROP Measurement Methodology
NBS Measurement Methodology
Low Frequency Noise
Acoustic Value of Portable Air Compressor Doors
Portable Air Compressor Noise Propagation
Ground Reflections
Path Discontinuities
Section 8 AVAILABLE NOISE CONTROL TECHNOLOGY
United States Technology
Gasoline Engine Powered Compressor
Diesel Powered Compressor, Less Than 500 CFM
Diesel Engine Powered Air Compressor Greater Than
500 CFM Capacity -
European Technology
Section 9 ECONOMIC STUDY
Page
6-12
6-12
6-12
6-13
6-14
6-14
7-1
7-2
7-5
7-5
7-9
7-9
7-14
7-14
7-17
7-17
7-22
7-22
7-27
7-27
7-27
8-1
8-1
Industry Background
8-5
8-7
8-8
9-1
9-2
IV
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TABLE OF CONTENTS (Cont)
Dollar Sales
Portable Air Compressor Prices
Percent Distribution by Type Compressor
Unit Sales
Price Per CFM
Regulatory Options Investigated
Impacts On List Prices of Alternative Noise Emission Standards
Economic Impacts of Alternative Regulatory Options
Price and Sales Impacts
Impact on Industry Employment
Cost of Compliance
User Costs
Market Impact
Foreign Trade
Individual Impacts
Disruptive Impacts
Summary
Section 10 EVALUATION OF EFFECTS OF PORTABLE AIR
COMPRESSOR NOISE ON PUBLIC HEALTH AND
WELFARE OF THE U.S. POPULATION
Construction Site Noise Impact
Actual Population Exposed to Construction S' Noise
Section 11 ENFORCEMENT
Production Verification
Selective Enforcement Auditing
Enforcement Action
Remedies
Labeling
In-use Compliance
Page
9-2
9-2
9-3
9-3
9-5
9-7
9-9
9-13
9-13
9-17
9-17
9-18
9-23
9-24
9-24
9-25
9-26
10-1
10-7
10-14
11-1
11-1
11-2
11-6
11-7
11-7
11-8
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TABLE OF CONTENTS (Cont)
Page
Section 12 ENVIRONMENTAL EFFECTS OF NOISE EMISSION
REGULATION OF PORTABLE AIR COMPRESSORS 12-1
Impact Related to Acoustical Environment 12-1
Impact Related to Land 12-1
Impact Related to Water 12-1
Impact Related to Air 12-1
Impact Related to Energy 12-2
REFERENCES R-l
APPENDICES
A Docket Analysis A-l
B Method to Evaluate the Impact of Portable
Air Compressor Noise on Public Health
and Welfare B-l
C Cost Analysis of Production Verification and
Selective Enforcement Auditing For The
Portable Air Compressor Industry C-l
VI
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LIST OF TABLES
Number Page
2-1 Estimated Number (in Millions) of People in Residential Areas
Subjected to Different Kinds and Levels of Outdoor Noise 2-2
2-2 Typical Construction Site Equipment Sound Levels (in dBA) and
Associated Sound Energy (in KW-hrs/day) 2-3
2-3 Contribution to Construction Site Noise by Individual Pieces
of Construction Equipment 2-5
2.4 Contribution of Portable Air Compressor Noise to Construction
Site Noise 2-6
4-1 Typical Energy Average Noise Level, dBA, at Construction
Site Boundaries 4-4
4-2 Estimated Sales of Portable Air Compressors by Major
Manufacturers, 1974 4-6
4-3 Estimated Percentage of Total Portable Air Compressor Unit
Shipments by End Use Market, 1967-1974 4-7
4-4 Estimated Shipments of Quieted Portable Air Compressors as a
Percent of Total Unit Shipments by Market Segment 4-8
4-5 Type of Compressor Offered by Manufacturer 4-10
4-6 Portable Air Compressor Capacities in CFM Offered by
Manufacturers 4-11
5-1 Type of Local Noise Ordinances for Construction for Selected
Populations 5-2
5-2 Type of Local Noise Performance Standards for Construction 5-2
6-1 Microphone Position Coordinates - NBS Methodology 6-8
6-2 Coordinates of Additional Positions - NBS Methodology 6-9
7-1 Compressors Tested and Test Methodology Employed 7-3
7-2 Comparison of CAGI/PNEUROP Average Side with Overhead
Noise Levels 7-4
7-3 Noise Levels of Standard Compressors Using the CAGI/PNEUROP
Measurement Method 7-6
7-4 Noise Levels of Silenced Compressors Using the CAGI/PNEUROP
Measurement Method 7-7
7-5(a) Percent and Number of Portable Air Compressors with Noise
Levels Not in Excess of a Particular Value 7-10
Vll
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LIST OF TABLES (Cont)
Number Pa§e
7-5(b) Percent and Number of Portable Air Compressors with Noise
Levels Not in Excess of a Particular Value 7-11
7-5 (c) Percent and Number of Portable Air Compressors with Noise
Levels Not in Excess of a Particular Value 7-12
7-6 Repeatability of Noise Levels of Four Models
The Ingersoll Rand DXL 900S Compressor 7-14
7-7 Air Compressor Noise Directivity 7-15
7-8 Sound Power Level Comparisons 7-18
7-9 Comparison of Portable Air Compressor Sound Power Levels
Calculated from Near and Far Field Data 7-21
7-10 Comparison of dBA Levels with dBC Levels of Standard Portable
Air Compressors 7-23
7-11 Comparison of dBA Levels with dBC Levels of Silenced Portable
Air Compressors 7-24
7-12 Effect on Standard Portable Air Compressor Noise of Opening
the Equipment Compartment Access Doors 7-26
-7-13 Effect on Silenced Portable Air Compressor Noise of Opening
the Equipment Compartment Access Doors 7-26
8-1 Mean Noise Reduction Between "Standard", "Quieted", and
"Quietest" Units 8-4
8-2 Worthington Compressor 160 QT Component Noise Levels 8-5
8-3 Portable Air Compressor Noise Reduction 8-6
8-4 Atlas Copco Compressor (VSS170 Dd) Component Noise Levels 8-6
8-5 Worthington Compressor 750 QTEX Component Noise Levels 8-8
9-1 Estimated Dollar Value of Annual Shipments of Portable Air
Compressors: 1967-1972 9-2
9-2 Estimates of Portable Air Compressor Average 1975 List Prices 9-3
9-3 Distribution of Engine Types and Compressor Design Types
According to Rated Engine Capacity in cfm at 100 psig 9-4
9-4 Unit Sales of Portable Air Compressors, 1967-1973 9-4
9-5 Portable Air Compressor 1972 Sales by Power Source Type
and Capacity Category 9-5
9-6 Noise Emissions and Price Per Rated cfm of Standard and
Quieted Versions of 1973 Compressors of the Same Model 9-6
9-7 Initial Sound Level Limits Selected for Study 9-7
9-8 Regulatory Options 9-8
9-9 Impact of Portable Air Compressor Noise Emission Regulation 9-10
Vlll
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LIST OF TABLES (Cont)
Number Page
9-10 Estimated Portable Air Compressor List Price Increases by
Major Engine/Capacity Class and All Models 9-11
9-11 Comparison of Estimated Portable Air Compressor List Price
Increases Derived Under Two Assumptions 9-12
9-12 Estimates of Increased Prices and Decreased Sales Associated
with the Regulatory Options 9-16
9-13 Estimates of the Annual Aggregate Increase in Purchase Cost
Related to Alternative Regulatory Options 9-19
9-14 First Year User Annualized Costs of Alternative Regulatory Options 9-21
9-15 100 Percent Quieted Population User Annualized Costs of
Alternative Regulatory Options 9-22
9-16 Summary of Estimated Price Increases 9-26
9-17 Summary of Estimated Sales Reductions 9-26
9-18 Summary of Estimated Annual Aggregate Increase in Purchase Price 9-27
10-1 (a) Usage Factors of Equipment in Domestic Housing Construction 10-3
10-1 (b) Usage Factors of Equipment in Nonresidential Construction 10-4
10-l(c) Usage Factors of Equipment in Industrial Construction 10-5
10-l(d) Usage Factors of Equipment in Public Works Construction 10-6
10-2 Effect of Change Upon the Population Impacted by Construction
Site Noise Resulting From Portable Air Compressor and Truck
Noise Regulations 10-9
10-3 Contribution of Portable Air Compressor Noise to Construction
Site Noise 10-12
10-4 Portable Air Compressor Noise Reduced by Category 10-13
10-5 Effect of Portable Air Compressor and Truck Noise Emission
Regulations on the U.S. Population Exposed to Construction
Site Noise 10-15
C-l Assumptions Used to Estimate Portable Air Compressor Testing
Costs C-2
C-2 Summary of Enforcement Costs C-4
IX
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LIST OF ILLUSTRATIONS
Number Page
5-1 New Product Noise Standards for Construction Equipment 5-3
5-2 Foreign Compressor Noise Regulations 5-5
6-1 CAGI/PNEUROP Method Microphone Locations 6-2
6-2 Schematic Diagram of 10 Microphone Locations at the Center of
Elements of Equal Area on the Surface of a Hemisphere about
a Sound Source 6-4
6-3 Relative Coordinates for 10 Points of Hemisphere of Radius R 6-5
6-4 Microphone Placement - NBS Methodology 6-7
6-5 Microphone Locations to Measure Portable Air Compressor Noise 6-13
6-6 Recommended Portable Air Compressor Noise Data Sheet 6-15
7-1 Comparison between Overhead Noise Level and CAGI/PNEUROP
Level "' 7-5
7-2 Noise of Standard and Silenced Compressors as a Function of
Capacity - CFM 7-8
7-3 Comparison of Manufacturer Supplied Data with Survey Data 7-13
7-4 Horizontal Directivity of Ingersoll-Rand (DXL 900S) Compressor 7-16
7-5 Far-Field Measurement Microphone Array 7-19
7-6 Representative Near-Field Measurement Positions 7-20
7-7 Portable Air Compressor C-Weighted minus A-Weighted Levels
Versus Capacity - CFM 7-25
7-8 Effect of Microphone Height on A-Weighted Sound at 7 Meters 7-28
7-9 Configurations of Locations of Compressors at Construction Sites 7-29
8-1 Noise Control Applied to the Ingersoll-Rand Model DXL 900 8-2
8-2 Noise Control Applied to the Atlas-Copco Model VT85 Dd 8-3
^
10-1 Effect of Portable Air Compressor Noise on the U.S. Public
Impacted by Construction Noise 10-10
10-2 Construction Site Noise Impact Reduction Caused by Portable Air
Compressor and Truck Noise Regulation 10-11
11-1 Operating Characteristic Curves for Sampling Plans 11 -5
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Section 1
PROLOGUE
STATUTORY BASIS FOR ACTION
Through the Noise Control Act of 1972 (86 Stat. 1234), Congress established a national
policy "to promote an environment for all Americans free from noise that jeopardizes their
health and welfare." In pursuit of that policy, Congress stated in Section 2 of the Act "while
primary responsibility for control of noise rests with state and local governments, Federal
action is essential to deal with major noise sources in commerce, control of which requires
National uniformity of treatment." As part of this essential Federal action, Subsection 5(b)(l)
requires that the Administrator of the U. S. Environmental Protection Agency, after consul-
tation with the appropriate Federal agencies, publish a report or series of reports "identifying
products (or classes of products) which in his judgment are major sources of noise." Section
6 of the Act requires the Administrator to publish proposed regulations for each product
identified as a major source of noise and for which, in his judgment, noise standards are
feasible. Such products fall into various categories, of which construction equipment is one.
Pursuant to Subsection 5(b)(l), the Administrator has published a report identifying portable
air compressors as a major source of noise.
PREEMPTION
Section 6(e)(l) of the Noise Control Act states that after the effective date of a Federal
regulation "no State or political subdivision thereof may adopt or enforce...any law or regula-
tion which sets a limit on noise emissions from such new product and which is not identical
to such regulation of the Administrator." Section 6(e)(2), however, states that "nothing in
this section precludes or denies the right of any State or political subdivision thereof to
establish and enforce controls on environmental noise (on one or more sources thereof)
through the licensing, regulation, or restriction of use, operation or movement of any product
or combination of products." The central point to be developed here is the distinction
between noise emission standards on products, which may be preempted by Federal regula-
tions, and standards on the use, operation, or movement of products, which are reserved to
the states and localities by Section 6(e)(2).
1-1
-------
Section 6(e)( 1) forbids state and local municipalities from controlling noise from prod-
ucts through laws or regulations that prohibit the sale (or offering for sale) of new products
for which different Federal noise emission standards have already been promulgated. States
and localities may augment the enforcement duties of the EPA by enacting a regulation
identical to the Federal regulation, since such action on the state or local level would assist in
accomplishing the purposes of the Act. Further, state and local municipalities may regulate
noise emissions for all new products that were manufactured before the effective date of the
Federal regulation(s).
Section 6(e)(2) explicitly reserves to the states and their political subdivisions a much
broader authority: the right to "establish and enforce controls on environmental noise (on
one or more sources thereof) through the licensing, regulation or restriction of the use, opera-
tion, or movement of any product or combination of products." Environmental noise is
defined as the "intensity, duration, and character of sounds from all sources" (Section 2[ 11 ]).
Limits may be proposed on the total aracter and intensity of sounds that may be emitted
from all noise sources, "products and mbinations of products".
State and local governments may regulate community oise levels more effectively and
equitably than the Federal government due to their perspective on and knowledge of state
and local situations. The Federal Go\ ernment may assume the duties involved in regulating
products distributed nationwide bee .e it is required and equipped to do so. Congress
divided the noise emission regulation power in this manner to allow each level of government
to fulfill that function for which it is best suited. Through the coordination of these divided
powers, a comprehensive regulatory p? 'am can be effectively designed and enforced.
One example of the type of regulation left open to the localities is the property line
regulation. This type of regulation would limit the level of environmental noise reaching the
boundary of a particular piece of property. Noise emitters would be free, insofar as state
regulations are concerned, to use any products whatsoever, as long as they are used or
operated in such a fashion so as not to emit noise in excess of the state-specified limits. This
type of regulation may be applied to many different types of properties, ranging from
residential lots to construction sites.
In such a case, state and local regulation of air compressors may take the form of, but
would not be limited to, the following examples:
• Quantitative limits on environmental noise received in specific land use zones, as in
a quantitative noise ordinance.
• Nuisance laws amounting to operation or use restrictions.
1-2
-------
• Regulations limiting the amount of environmental noise at the boundary of the
construction site.
• Other similar regulations within the powers reserved to the states and localities by
Section 6(e)(2).
In this manner, local areas may balance the issues involved to arrive at a satisfactory
environmental noise regulation(s) that protect the public health and welfare as much as
deemed possible.
LABELING
The enforcement strategies outlined in Section 2 of this document will be accompanied
by the requirement for labeling products distributed in commerce. The label will provide
notice to a buyer that a product is sold in conformity with applicable regulations. A label
will also make the buyer and user aware that the air compressor possesses noise attenuation
devices and that such items should not be removed or rendered inoperative. The label may
also indicate the associated liability for such removal or tampering.
IMPORTS
The determination of whether individual new products comply with the Federal regula-
tion will be made.by the U.S. Treasury Department (Customs), based on ground rules
established through consultation with ^ Spcr^t- >f the Treasury.
It is anticipated that enforcement of the actual noise standard by the use of a standard
test procedure would be too cumbersome for Customs to handle, especially in view of the
tremendous bulk of merchandise they must pass on each day. A case in point occurs with
imported automobiles, in which Ostrr-- ''.specters presently assess compliance with
requirements of the Clean Air Ac. s^ •/ on the basis of the presence or absence of a label
in the engine compartment. A similar mechanism (labeling) appears viable for use to assess
compliance of portable air compressors with the proposed regulations.
1-3
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Section 2
RATIONALE FOR REGULATION OF THE PORTABLE
AIR COMPRESSOR
To develop an EPA criterion for identifying products as major sources of noise, first
priority was given to those products that contribute most to overall community noise expo-
sure. Community noise exposure is defined as that exposure experienced by the community
as a whole as the result of the operation of a product or group of products, as opposed to that
exposure experienced by the user(s) of the product(s).
In this section, it is shown that while portable air compressors may not produce the
highest sound level at construction sites, they do contribute significantly to community noise
exposure, thus justifying their regulation. Air compressors rank with dump trucks and con-
crete trucks in producing the highest sound energy per day.
In terms of assessment, community noise exposure was evaluated in terms of the day/
night equivalent sound level (Ldn) [ 11 that was developed especially as a measure of commun-
ity noise exposure. Since Ldn is an equivalent energy measure, it can be used to describe the
noise in areas in which noise sources operate continuously or intermittently but are present
enough of the time to emit a great deal of sound energy in a 24-hour period.
Studies have been made of the number of people exposed to various levels of community
noise [2, 3]. Table 2-1 summarizes the estimated number of people in residential areas sub-
jected to urban traffic noise, aircraft noise, construction site noise, and freeway traffic noise
at or above an outdoor Ldn of 60,65, and 70 dB, respectively.
EPA has identified an outdoor Ldn of 55 dB [ 1 ] as the day/night equivalent sound
level requisite* to protect the public from long-term adverse health and welfare effects in
residential areas. Table 2-1 indicates that it will be necessary to quiet the major sources con-
tributing to urban traffic noise, construction site noise, freeway traffic noise, and aircraft
noise if this level is to be achieved.
* With an adequate margin of safety and without consideration of the cost and technology
involved to achieve an Ldn of 55 dB.
2-1
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Table 2-1
ESTIMATED NUMBER (in Millions) OF PEOPLE IN RESIDENTIAL
AREAS SUBJECTED TO DIFFERENT KINDS AND LEVELS OF
OUTDOOR NOISE (12)
Outdoor
Ldn Level
70dB+
65dB+
60 clB+
Urban Traffic
Noise
4-12
15-33
40-70
Aircraft
Noise
4-7
8-15
16-32
Construction
Site Noise
1-3
3-6
7-15
Freeway
Noise
1-4
2-5
3-6
IDENTIFICATION OF MAJOR SOURCES
Section 6(a)(l)(C) of the Noise Control Act specifies four possible categories of products
that may be regulated by the Administrator:
1. Construction equipment.
2. Transportation equipment (including recreational vehicles and related xjuipment).
3. Any motor or engine (including any equipment of which an engine an integral
part).
4. Electrical or electronic equipment.
Pursuant to Section 3(3)(A) aircraft are excluded as products under Section 6 of the
Act. Aircraft noise regulations will be proposed to the FAA as delineated in Section 7 of the
Act. Medium- and heavy-duty trucks contribute the most sound energy to the environment
of any highway vehicle and, as such, have been identified for regulation as major noise
sources. Consequently, in view of the foregoing and data contained in Table 2-1, attention
is focused on construction site noise.
2-2
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CONSTRUCTION EQUIPMENT
The sound level of a product and the level of background noise determine the intrusive-
ness of a product's sound emission, which has been shown to determine annoyance in some
situations. Table 2-2 indicates that pile drivers and rock drills are perceived as the loudest
pieces of construction equipment, but sound energy measurements indicate that these products
do not contribute as much sound energy to the environment as other products operating on
construction sites. The fact that dump trucks, portable air compressors, and concrete mixers
(trucks) produce sound levels equal to or lower than other construction equipment and yet
produce higher total sound energy emissions means that these are the most widely used pieces
of construction equipment.
Table 2-2
TYPICAL CONSTRUCTION SITE EQUIPMENT SOUND LEVELS (in dBA)
AND ASSOCIATED SOUND ENERGY (in KW-hrs/day)
Construction Equipment
1. Dump truck
2. Portable air compressors
3. Concrete mixer (Truck)
4. Paving Breaker
5. Scraper
6. Dozer
7. Paver
8. Generator
9. Pile driver
10. Rock drill
11. Pump
12. Pneumatic tools
13. Backhoe
Typical
Sound Level
at 50 Feet
88
81
85
88 '
88
87
89
76
101
98
76
85
85
Estimated Total
Sound Energy
296
147
111
84
79
78
75
65
62
53
47
36
33
2-3
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A control technology report [14] on dump trucks and concrete mixers indicates that
their contribution to construction site noise is largely engine-related noise that will be con-
trolled when these trucks meet the standards proposed for medium- and heavy-duty trucks.
This leaves portable air compressors as the major source of sound energy and the most widely-
used product among pieces of equipment contributing to construction site noise. This is
further confirmed by the data contained in Tables 2-3 and 2-4, which show that portable air
compressors contribute significantly to construction site noise.
Table 2-3 shows the contribution to construction site noise by individual pieces of con-
struction equipment, while Table 2-4 shows the ranking of the portable air compressor noise
contribution to construction site noise. As shown by the tables, the portable air compressor
ranks high on the list of contributors to construction site noise.
2-4
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Table 2-3
CONTRIBUTION TO CONSTRUCTION SITE NOISE BY INDIVIDUAL
PIECES OF CONSTRUCTION EQUIPMENT
Construction Ecjuipment
Backhoe
Dozer
Grader
Loader
Paver
Roller
Scraper
Shovel
Truck
Concrete mixer
Concrete pump
Crane, derrick
Crane, mobile
Air compressor
Generator
Pump
Paving hammer
Pile driver
Pneumatic tool
Rock drill
Concrete vibrator
Saw
Percent Contribution* to Construction Site Noise
Residential
5.6
10.0
2.0
6.3
2.5
0.5
3.1
2.2
6.3
28.1
_ **
-
5.6
4.6
1.8
1.3
0.8
-
11.3
2.2
4.4
-
Public Works
2.2
6.8
1.9
3.0
10.8
1.7
4.8
1.0
21.5
10.0
-
1.9
0.7
6.1
2.5
2.7
8.5
-
1.4
13.8
-
0.2
Industrial
7.1
8.9
0.3
4.4
1.7
0.2
1.7
2.5
11.3
8.9
2.1
1.6
1.0
10.0
1.1
-
5.1
20.6
6.3
5.1
0.6
0.9
Nonresidential
3.5
4.8
0.2
2.5
0.8
-
1.5
1.2
7.7
6.1
2.2
3.1
1.9
16.9
2.5
3.5
2.5
24.6
3.1
4o8
0.4
3.1
* On an energy bases
** A dash (-) indicates the equipment is not primarily used at the type of site
cited or the percent contribution is less than 0.1 percent.
2-5
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Table 2-4
CONTRIBUTION OF PORTABLE AIR COMPRESSOR NOISE TO CONSTRUCTION
SITE NOISE
Site
Residential
Public Works
Industrial
Nonresidential
% Contribution to the
Construction Site Noise
by the Portable Air Compressor*
4.6
6.1
10.0
16.9
Rank at Site**
7th
7th
3rd
2nd
* On an energy basis.
** On an energy basis relative to 20 typical pieces of equipment employed at
construction sites.
2-6
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Section 3
BACKGROUND INFORMATION
This section summarizes the background information accrued by the Environmental
Protection Agency's Office of Noise Abatement and Control relevant to the noise emission
regulation for portable air compressors. The requisite regulation is to protect the health
and welfare of the American public, taking into account the degree of noise reduction
achievable through the application of best available technology and the cost of compliance.
The information has been derived from numerous sources. The EPA contracted with
Bolt, Beranek and Newman (BBN), an acoustical consulting firm, and A. T. Kearney, Manage-
ment Consultants, and has utilized the data gathering and information collecting capabilities
of Informatics, Inc. The EPA has also developed an interagency agreement with the National
Bureau of Standards (NBS) for technical assistance. BBN provided cost and technology
support [5, 6, 7]; A. T. Kearney Management Consultants provided economic analysis
support [8]; Informatics, Inc. submitted reports addressing domestic and foreign regulations
relating to construction equipment and portable air compressors [9, 10]; and NBS provided
technical support in the development of methodology to test and measure portable air
compressors [11].
The EPA and contractor personnel made several visits to compressor manufacturers,
distributors, and users to obtain the most accurate information available for use in the
development of the proposed portable air compressor regulations. NBS personnel held two
meetings with industry technical experts to discuss and exchange information on measure-
ment methodology.
The EPA published a Notice of Proposed Rulemaking for Portable Air Compressors
on October 29, 1974 (39 FR 38186). The docket, which afforded the public an oppor-
tunity to comment on the proposed regulation, closed on December 30, 1974. Additionally,
two public hearings were held regarding the proposed rulemaking. Public notice was pro-
vided on January 22, 1975 (40 FR 3466) and hearings were held on February 18, 1975, in
Arlington, Va., and on February 25, 1975, in San Francisco, Calif. The following is a list
of individuals and organizations submitting comments to the various dockets. A summary
of the comments received and responses, thereto, is presented in Appendix A.
3-1
-------
Portable Air Compressor NPRM Docket
Richard Gimer
W. S. Price
John Y. Richards
E. A. Long
J. M. Ombrello
Gerald H. Shaff
J. J. McNally
D. E. Kipley
Bruce J. Smith
H. T. Larmore
Robert A. Heath
W. J. Cowan
C. M. Copeland
Richard Ostwald
William W. Lang
Lawrence H. Hodges
R. D. Harlow
Mary Ann Zimmerman
Dr. Robert W. Young
N. J. E. Hartwell
R. W. Wiedow
Walter L. Black
M. E. Rumbaugh, Jr.
George J. Stradtner
Hugh I. Myers, Jr.
Thomas F. Scanlan
Robert F. Hand
A. J. Cox
Don L. Kerstetter
F. A. DelleCave
Joseph O'Neill
Charles Stewart
Compressed Air & Gas Institute
Worthington Compressor
Joy Manufacturing
Chicago Pneumatic Equipment Division
LeRoi Division, Dresser Industries
Walker Manufacturing Company
Caterpillar Tractor Company
Gardner-Denver Company
Bucyrus-Erie
Construction Industry Manufacturers Assn.
Walker Manufacturing
Barber-Greene Company
P. K. Lindsay Company
Smith Air Compressors
Institute of Noise Control Engineering
J. I. Case
Schramm, Inc.
Cummins Engine
Acoustical Society of America
Perkins Engines Company
Northern Illinois Gas Company
Clark Equipment Company
Schwitzer Engineered Components
Grimmer-Schmidt Corp.
Citizen
Grossmont College
Clark Equipment
Construction Industry Manufacturers Assn.
American Road Builders' Association
Caterpillar Tractor Company
Penna. Dept. of Environmental Resources
Ingersoll-Rand
Quincy Compressor (Colt Industries)
Machinery and Allied Products Institute
-------
Portable Air Compressor Hearings — Arlington, Va.
Richard Girner Compressed Air & Gas Institute
accompanied by:
George Diehl Ingersoll Rand
Robert Harlow Schramm, Inc.
Richard Ostwald Gordon Smith and Company
Bill Heckenkamp Gardner-Denver Company
William Price Worthington Compressors, Inc.
Richard Geney Atlas Copco, Inc.
John Richards Joy Manufacturing
Lawrence H. Hodges J. I. Case Company
Max E. Rumbaugh, Jr. Schwitzer Engineered Components
Andrew Kauders General Services Administration
David Staples District of Columbia
Don Gallay City of Chicago
John A. Hilcken Arlington County, Virginia
Robert Hand Clark Equipment Company
Portable Air Compressor Hearings — San Francisco, Calif.
John McNally Caterpillar Tractor Company
Robert Levy City of San Francisco
Dr. Donna Dickman Washington Hearing and Speech Society
H. T. Larmore Construction Industry Manufacturers Assn.
Alvin Greenwald Citizen
John W. Ross City and County of San Francisco
Robert L. Greivell Koehring Company
Vincent Salmon Industrial Services, Inc:
J. Sx Mills Industrial Services, Inc.
Richard Anderson General Acoustics
Paul Laesch Sullair Corporation
3-3
-------
Section 4
THE INDUSTRY AND THE PRODUCT
GENERAL DESCRIPTION
Noise associated with construction has become a major problem in many cities and
towns. The trend toward urban renewal and more high-rise structures has created an almost
perpetual din in city streets. Equipment associated with construction activities has become
more numerous, and the time span for construction at a given site has lengthened. Residents
in proximity to a high-rise construction site may well plan on 2 years of elevated noise levels
as the structure is built.
The basic unit of construction activity is the construction site, which exists in both
space and time. The temporal dimension consists of various sequential phases that change
the character of the site's noise output as work progresses. These phases are discussed
further subsequently. In the case of building construction, the spatial character of the site
is self-evident.
Construction sites are typically classified in the 15 categories in which construction
data is reported by the U.S. Bureau of the Census and various state and municipal bodies.
The categories are:
• Residential buildings:
One to four family
Five family and larger
• Nonresidential buildings:
Office, bank, professional
Hotel, motel, etc.
Hospitals and other institutions
Schools
Public works buildings
Industrial
Parking garages
4-1
-------
Religious
Recreational
Store, mercantile
Service, repair station
• Municipal streets
• Public works (e.g., sewers, water mains)
For purposes of allocating construction effort among the different types of sites, it is
possible to group the nonresidential sites into four larger categories differentiated by the
cost of the average building in each category, as well as by the distribution of effort among
the various construction phases. These four groups, in order of decreasing average cost per
building, are [2] :
• Office buildings, hospitals, hotels
• Schools, public works buildings
• Industrial buildings, parking garages
• Stores, service stations, recreational buildings, and religious buildings
Construction is carried out in several reasonably discrete steps, each of which has its
own mix of equipment and, consequently, its own noise characteristics. The phases (some
of which can be subdivided) are:
• Building construction
1. a. Clearing
b. Demolition
c. Site preparation
2. Excavation
3. Placing foundations
-------
4. a. Frame erection
b. Floors and roof
c. Skin and windows
5. a. Finishing
b. Cleanup
• City streets
1. Clearing
2. Removing old roadbed
3. Reconditioning old roadbed
4. Laying new subbase, paving
5. Finishing and cleanup
• Public works
1. Clearing
2. Excavation
3. Compacting trench floor
4. Pipe installation, filling trench
5. Finishing and cleanup
The most prevalent noise source in construction equipment is the prime mover, e.g.,
the internal combustion engine (usually of the diesel type) used to provide motive and
operating power. Engine powered equipment may be categorized according to its mobility
and operating characteristics, as:
-------
• Earthmoving equipment (highly mobile).
• Handling equipment (partly mobile).
• Stationary equipment (The air compressor is in the latter category).
Typical average noise levels [2] at construction site boundaries are shown in Table 4-1
for each phase of construction activity.
It may be generally agreed that construction site noise can be alleviated by reducing
the noise levels of individual pieces of equipment employed within the site [2,3].
Other methods also exist that, by themselves or in combination, may be used to control
construction site noise. For example:
• Replacing individual operations and techniques by less noisy ones.
• Selecting the quietest of alternate operations to keep average noise levels low.
• Locating noisy equipment away from site boundaries, particularly near noise sensitive
land use areas.
• Providing enclosures for stationary items of equipment and barriers around particularly
noisy areas on the site.
Table 4-1
TYPICAL AVERAGE NOISE LEVEL, dBA,
AT CONSTRUCTION SITE BOUNDARIES<2)
Phases of
.Construction •
Ground clearing
Excavation
Foundation
Erections
Finishing
Domestic
Housing
83
88
81
81
88
Office Building
Hotel, Hospital
School, Public Work
84
89
78
-87
89
Industrial
Recreation, Store,
Service Station
84
89
77
84
89
Highways
Roads, Sewers,
Trenches
84
88
88
79
84
4-4
-------
There is no doubt that the construction industry can take steps to reduce its noise
through equipment selectivity or operational procedure noise control schemes. However,
regulations are needed to assure that the basic steps are taken uniformly by all components
of the industry.
THE INDUSTRY
The portable air compressor industry is a mature and highly competitive industry.
Manufacturers of portable air compressors vary significantly in size, financial strength, manu-
facturing capability, applied technology, marketing ability, and extent of product diversifi-
cation. Seventeen manufacturers, currently active in the domestic market, have been identi-
fied. Two manufacturers import components and assemble units in the United States, and
one imports completely assembled units. Sales in 1974 of S150 million resulted from ship-
ments of more than 16,000 units. Table 4-2 presents a listing of manufacturers and an
estimated dollar value of their portable air compressor sales. Eight manufacturers have
over 90 percent of the market.
Nine of the 17 manufacturers are divisions or subsidiaries of large corporations with
assets in excess of $100 million. These are: Atlas Copco (importer), Chicago Pneumatic,
Davey, Gardner-Denver, Ingersoll-Rand, Joy, Le Roi. Quincy and Worthington. Sales of
these corporations (parent company) in 1972 ranged from $182 million to $906 million.
These corporations are not highly specialized in the construction equipment industry [8],
but are extensively diversified, producing a wide variety of products sold in other industries.
Three medium-sized manufacturers have assets ranging from $10 million to $30 million.
These are Jaeger, Schramm, and Sullair. Sales of these corporations in 1974 ranged from
$10 million to $40 million. Five manufacturers are small companies with assets ranging
from $0.5 million to $3.0 million. They are American Jenback (importer), Grimmer-Schmidt,
Kent Air Tool, Lindsay, and Gordon Smith [8]. The medium and small-sized manufacturers
typically specialize in portable and stationary compressors and a few other products sold
primarily outside the construction equipment market.
Portable air compressor manufacturing facilities are concentrated in the northeast and
north-central United States. Plants vary considerably in terms of size, efficiency, technology,
and employment. Detailed plant location, employment and factory production information
is presented in Reference 8. While some firms have efficient plants utilizing the most up-to-
date technology, others have old, extremely inefficient plants utilizing technology and
4-5
-------
Table 4-2
ESTIMATED SALES OF PORTABLE AIR COMPRESSORS
BY MAJOR MANUFACTURERS, 1974
Manufacturer
American Jenback
Atlas Copco
Chicago Pneumatic
Davey
Gardner-Denver
Grimmer-Schmidt
Ingersoll-Rand
Jaeger
Joy
Kent Air Tool
Le Roi
Lindsey
Quincy
Schramm
Gordon Smith
Sullair
Worthington
Millions of
0.5
1.0
6.0
0.5
16.0
0.5
37.0
5.0
19.0
1.0
10.0
1.8
3.0
2.5
4.0
23.0
Dollars
-2.0
- 3.0
- 8.0
-2.0
- 18.0
- 2.0
-42.0
- 6.0
- 23.0
- 2.0
- 12.0
- 2.0
-4.0
-4.5
- 5.5
- 25.0
9.0 - 11.0
production methods that are nearly obsolete. Generally, the larger manufacturers have the
more efficient plants.
Most manufacturers utilize only one plant for the production of portable air compressors.
Generally, these plants are also used for the production of related products, including station-
ary air compressors. However, each product is typically manufactured on a separate production
line or in a separate area.
Approximately 9,000 people are employed in plants that manufacture portable air com-
pressors. The exact employment attributable to the production of portable air compressors
is considered confidential. It has been estimated that the total portable air compressor pro-
duction employment is in the range of 2,000 to 3,000 employees.
The portable air compressor industry generally operates between 65 and 75 percent
capacity. However, during 1973 the industry operated in excess of 85 percent of capacity.
The industry has been constrained from further expansion by the difficulty in obtaining
deliveries of engines and other components.
4-6
-------
Manufacturers obtain raw materials and components from interdivisional transfers,
component suppliers, and raw material suppliers. The finished product is distributed through
construction equipment distributors (dealers) who sell or lease the product to the primary end
users (such as the construction and mining industries), other industries, and government
agencies. Table 4-3 indicates the estimated distribution of unit shipments by end-use market
during the years 1967 through 1974 [8].
Table 4-3
ESTIMATED PERCENTAGE OF
TOTAL PORTABLE AIR COMPRESSOR UNIT
SHIPMENTS BY END USE MARKET, 1967-1974
End Use Market
Percentage of Units Shipped
Construction industry
Public works and other non-building
construction
Commercial, institutional and industrial
building construction
Mining industry
Industrial users
Government agencies
Other users.
Total
50
20
8
7
12
3
100
The single largest user of portable air compressors is the construction industry, which
currently accounts for an estimated 70 percent of total units shipped. Government agencies
account for about 15 percent of the units, followed by mining and industrial users, sharing
another 15 percent of total shipments.
Channels of distribution traditionally are through independent, authorized distributors
and factory-owned distributors or branches. In excess of 50 percent of manufacturer shipments
4-7
-------
of new portable compressors reach the end user via rental/purchase agreements. Intermittent
use requirements result in a large rental market. The trend to increased rental of compressors
is expected to continue. Used equipment is also an important factor in the portable air
compressor market.
From 6 to 13 percent of total annual shipments are exported each year, imports have
been a minor factor in the market (less than 7 percent of the 1972 unit volume).
Most manufacturers currently offer quieted portable air compressors due to customer
demand resulting from OSHA and local noise regulations. Domestic shipments of quieted
units vary by compressor capacity and power source type, as shown in Table 4-4.
Table 4-4
ESTIMATED SHIPMENTS OF QUIETED PORTABLE AIR COMPRESSORS
AS A PERCENT OF TOTAL UNIT SHIPMENTS BY MARKET SEGMENT
Power Source Type
Gasoline engine
Diesel engine
Air Flow Capacity
Range (CFM)
75-124
124-250
124-249
249-599
600-899
900 and over
Estimated Percent
of Total Shipments
20
20
20
20
10
10
•
THE PRODUCT
Portable air compressors are designed mainly to power pneumatic tools and equipment
at a construction job site. Primary applications include the generation of air power for:
• Operating hand tools
• Tunneling operations
• Mixing and atomizing to shoot fine particle material into place
4-8
-------
• Pneumatic conveying of small particle material
• Air-operated centrifugal pumps
• Air-powered hoist drums or brakes
• Snow production.
Compressors generally are rated according to maximum flow rate at a pressure of 100
pounds per square inch (psi) (although some firms have units rated up to 150 psi). Portable
air compressors used at construction sites generally range in flow capacity from a low of 75
cfm to ; high well in excess of 2000 cfm.
Almost all large units are diesel-engine driven, screw-type compressors. The intermediate
sized units are diesel and gasoline-engine driven, screw and rotary type compressors, while the
smaller types are primarily gasoline-engine driven, screw, rotary, and reciprocating type
compressors.
The portable compressors of interest are designed to be towed as trailers on two or
four oibber-tired wheels. They have weights ranging from 1 to 14 tons, lengths ranging
from 5 to 19 feet, and heights ranging from a little less than 6 feet to almost 10 feet.
Mounted on the trailer are the compressor, an air receiver, the driving engine, cooling system,
fuel tanks, tool boxes, and an enclosure. The enclosure itself, when designed for noise insula-
tion, can comprise as much as 10 percent of the total weight.
The most widely manufactured compressor in the United States today is the rotary
screw-type unit. The screw type compressor is a single-stage unit that provides a high
flow-rate-to-size ratio and offers high reliability due to its few moving parts. An engine
occupying 5 to 15 times the volume occupied by the basic compressor is needed along
with the accompanying cooling and exhaust system to drive the compressor. In most
cases, the engine is directly coupled to the male screw element, which then drives the
female element.
The basic screw-type compressor unit accounts for only a small fraction of the weight
and size of an operating portable compressor. Typically, rotary screw units used in portable
compressors are smaller in size than an automobile automatic transmission. Likewise, the
compressor mechanism itself produces little of the noise generated during operations.
Most U.S. manufacturers are phasing out their line of sliding-vane rotary compressors,
probably because they are reputed to require more maintenance and are less economical to
operate than other types. Nevertheless, there are still several portable compressor sets of
4-9
-------
this type on the market. As in the case of the screw-type compressors, the compressor
itself is relatively small, but the necessary concomitant equipment is substantial. Some-
times the compressor is mounted in the receiving tank to save space.
The traditional reciprocating compressor is used today almost exclusively in portable
compressors delivering less than 250 cfm. Unlike the screw and rotary-vane types, it usually
requires several stages to achieve the required pressure. Consequently, the basic unit is a
larger fraction of the total weight and size of the complete compressor assembly.
Rotary-screw manufacturers tend to compete by specializing in one or two types of
portable air compressors in each market segment. Table 4-5 summarizes the types of com-
pressors offered by each portable air compressor manufacturer.
Table 4-5
TYPE OF COMPRESSOR OFFERED BY MANUFACTURER
Manufacturer
American Jenback
Atlas Copco
Chicago Pneumatic
Davey Compressor
Gardner Denver
Grimmer Schmidt
Ingersoll-Rand
Jaeger
Joy Manufacturing
Kent Air Tool
Le Roi
Lindsay
Quincy
Schramm
Gordon Smith
Sullair
Worthington
Rotary Screw
X
X
X
X
X
X
X
X
X
X
X
Reciprocating
X
X
X
X
X
X
Rotary Vane
X
X
X
X
X
X
X
X
The basic units used to gauge productive capacity and performance of portable
compressors are the engine type (diesel or gasoline) and air flow rating in cfm at 100 psi.
4-10
-------
Thirteen manufacturers, shown in Table 4-6, offer a complete line of portable air
compressor capacity while the remaining four offer only the smaller capacity units.
Table 4-6
PORTABLE AIR COMPRESSOR CAPACITIES IN cfm
OFFERED BY MANUFACTURERS
Manufacturer
American Jenback
Atlas Copco
Chicago Pneumatic
Davey Compressor
Gardner-Denver
Gr immer-S chmidt
Ingersoll-Rand
Jaeger
Joy Manufacturing
Kent Air Tool
LeRoi
Lindsay
Quincy
Schramm
Gordon Smith
Sullair
Worthington
Gasoline Engine
75-124
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
125-250
X
X
X
X
X
X
X
X
X
X
X
X
X
Diesel Engine
125-249
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
250-599
X
X
X
X
X
X
X
X
X
X
X
X
X
600-899
X
X
X
X
X
X
X
X
X
X
X
X
X
900 & over
X
X
X
X
X
X
X
X
X
X
4-11
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Section 5
EXISTING LOCAL, STATE, AND FOREIGN NOISE REGULATIONS
According to Section 6 of the Noise Control Act of 1972, the proposed Federal
regulations for new portable air compressors will preempt new product standards for com-
pressors at the local and state level* unless those standards are identical to the Federal
standard. Further, according to Section 9 of the Act, regulations will be issued to carry out
the provisions of the Act with respect to new products imported or offered for importation.
EPA reviewed available literature and conducted a survey to determine the number of
existing regulations that are applicable to construction equipment and portable air compressors
and that may be affected by proposed Federal regulations. In the following subsections, the
findings of the review are summarized.
LOCAL AND STATE REGULATIONS
Information on state and local construction noise regulations was obtained from 123
cities with populations in excess of 100,000 and from 226 cities with populations of less
than 100,000. In addition, information was received from 46 of the 50 states surveyed [9].
As indicated by Table 5-1, 27 of the 123 cities with a population in excess of 100,000
and 21 of the 226 cities with a population less than 100,000 have some form of a construction
regulation at this time. Of the 43 cities with some form of construction equipment regula-
tion, 36 have operational limits and 7 have new product standards as shown by Table 5-2.
Of the 46 states that replied to the survey, 4 had specific regulations for the noise of
construction equipment. Colorado, Indiana, New York, and Alaska have performance
standards, while Indiana has new product standards currently in force.
*Local and state governments are not prohibited from "establishing or enforcing controls
on environmental noise through licensing, regulation or restriction of the use, operation
or movement of any product" or from establishing or enforcing new product noise standards
for types of construction equipment not regulated by the Federal Government.
5-1
-------
Table 5-1
TYPE OF LOCAL NOISE ORDINANCES FOR
CONSTRUCTION FOR SELECTED POPULATIONS
Population
Over 100,000
Under 100, 000
TOTAL
No Specific
Law
54
157
211
Nuisance
Law
37
48
85
Ordinance
Under
Development
5
0
5
Performance
Standards
27
21
48
Total
123
226
349
Table 5-2
TYPE OF LOCAL NOISE PERFORMANCE STANDARDS
FOR CONSTRUCTION
Population
Over 100, 000
Under 100, 000
TOTAL
Operational Limits
18
18.
36
New Product
Standards
5
2
7
Since the Federal portable air compressor regulation will preempt existing or con-
templated local and state portable air compressor regulations, cities and states that
will be affected have been identified. Figure 5-1 shows that seven cities (and no states)
have new construction equipment noise standards. Also shown is that Grand Rapids,
Mich., and New York City, N.Y., have the most stringent standard along with the shortest
time period for compliance.
These seven regulations then, in part, will be preempted by the new Federal law on
portable air compressors. The new Federal law will preempt these jurisdictions only from
promulgating or enforcing a new product standard for portable air compressors. It will not
prohibit them from enforcing laws against other types of construction equipment and will
not prohibit them from establishing or licensing operational limits for portable air compressors.
5-2
-------
1/1/73
1/1/74
1/1/75
1/1/80
1/1/72
1/1/73
1/1/75
1/1/80
1/1/72
1/1/73
1/1/75
1/1/80
before 1/1/73
O after 1/1/73
3
O
IU
oc
u.
O
111
1/1/75
1/1/80
1/1/72
1/1/73
1/1/75
1/1/80
1/1/72
1/1/73
1/1/80
7/1/73
1/1/75
1/1/80
12/31/72
6/30/74
12/31/75
12/31/71
12/31/73
12/31/74
SALT LAKE CITY, UTAH @ 50 FEET
LOUISVILLE, KY. @ 50 FEET
DES PLAINES. ILL. @ 50 FEET
COOK COUNTY, ILL. @ 50 FEET
CHICAGO, ILL. @ 50 FEET
BOSTON, MASS. @ 50 FEET
GRAND RAPIDS, MICH. @ 50 FEET
NEW YORK CITY, N.Y.
@ 1 METER
KANSAS CITY, MO.
@ 1 METER
70
1 METER = 3.3 FEET
15.2 METERS = 50 FEET
75 80
SOUND LEVEL INdBA
I
85
I
90
I
95
Figure 5-1. New Product Noise Standards for Construction Equipment
5-3
-------
FOREIGN REGULATIONS
Over 300 inquiries were sent to foreign manufacturers of portable air compressors and
representatives of foreign nations who were knowledgeable in the field of environmental
noise [10]. These inquiries solicited information and comments in the following five areas.
1. The technology available to reduce the noise of portable air compressors and noise
level data for existing models of air compressors.
2. Legislation setting limits on the noise level of construction equipment, especially
portable ah" compressors.
3. The effects of government regulations on the cost of producing or marketing
portable air compressors that must be quieted.
4. Specifications for the noise levels produced by portable air compressors used in
government contracts.
5. Standards for measuring the noise level of air compressors.
Although information hi areas other than regulations was requested, in most
instances the individuals and countries responding did not address anything but the
applicable regulations on construction equipment.
Generally, it was found that foreign countries have regulations that deal specifically -
with construction noise in the following ways:
• Standards of recommended practice such as the Guidelines for Noise issued by the
National Federation of Building Trades Employers and the Ministry of Public
Works in the United Kingdom.
• Contract specifications between buyer and builder such as those in Norway or New
South Wales, Australia.
• General nuisance laws such as those in the various municipalities in Canada and
Paris, France.
• Regulation of the noise level in various land use areas. These laws frequently differ-
entiate between daytime and nighttime levels. Examples include Oslo, Norway;
Zurich, Switzerland; Sweden; and Vienna, Austria.
-------
• Regulation of the noise emission level of specific types of equipment, such as
portable air compressors.
The levels specified by the cities and nations regulating portable air compressor noise
are summarized in Figure 5-2.
VI
V-i
3 90
r-
-p
(fl
g 80
T3
t
<-{
0)
I
-0 70
i
60
1 UNITED KINGDOM
RECOMMENDED
CM
TV
L
|
i
C
L
R
6
u
,?
!
I
C
L
C«m > 353
Cfm < 353
SWEDEN
STOCKHOLM
SWEDEN
JAPAN
TOKVO. JAPAN
(D
r*» CM
«- (•*
VI £
1 ^
Ee
VI ti
E |I
u
CO
8*
a> T
f 0
I'
WEST Gl
a
| Cfm 176-353
2 1-10-75
rCf m > 353
1-10-72
-
rCf m > 353
1-10-75
(1) Some data corrected to 7 meters
(2) Some data corrected for sound level
(3) Levels are for any air flow currently available unless otherwise stated
Figure 5-2. Foreign Compressor Noise Regulations
5-5
-------
Section 6
MEASUREMENT METHODOLOGY
MEASUREMENT STANDARDS
• Numerous recommended practices, standards, and regulations for noise measurement
have been proposed by national and international organizations [13] to standardize the
measurement methodology used by industry, consumers, and government regulatory bodies.
The Society of Automotive Engineers (SAE) has published recommended practices and stan-
dards or draft documents that standardize the noise measurement methods for construction
equipment and construction sites [14, 15]. The American National Standards Institute (ANSI)
for the United States and the International Standards Organization (ISO) have developed,
through their member groups, numerous noise measurement standards. Of particular interest
to the portable air compressor manufacturers is the Compressed Air and Gas Institute (CAGI)
test code for measurement of sound from pneumatic equipment [ 16]. This standard has been
accepted for promulgation by ISO as ISO2 151-1972 and by ANSI as ANSI S5.1-1971. One
section is specifically devoted to portable air compressors and is widely used by portable air
compressor manufacturers to describe the sound pressure level of their products.
With consideration given to the possible use of sound power or sound power level to
describe portable air compressor noise, methods suitable for this type of description have
been investigated. Two methods investigated were:
1. The 10 point hemispherical method of Reference 17.
2. The National Bureau of Standards far and near field method of Reference 11.
In both methods, sound pressure levels are measured and sound power or sound
power level is computed. Further description of the sound pressure level and the sound
power/sound power level methods follows.
CAGI METHOD - SOUND PRESSURE LEVEL
Octave-band sound pressure levels from 63 to 8000 Hz and A-weighted sound levels are
obtained during idle and fullpower conditions at 10 locations around the compressor. The
locations are shown in Figure 6-1.
6-1
-------
Direction
of Maximum
Sound Level
Figure 6-1. CAGI/PNEUROP Method Microphone Locations
Octave-band data are used to show the characteristics of portable air compressor noise
at the microphone location at which the highest sound level was recorded.
A-weighted sound levels are used to calculate the average sound level at the 1- and 7-
meter microphone locations. The average level is calculated by one of the following three
methods:
1. Maximum Variation of 5 dB or Less. If the maximum variation in corrected sound
pressure levels is 5 dB or less, average the sound pressure levels arithmetically.
2. Maximum Variation of 5 to 10 dB. If the maximum variation hi corrected sound
pressure levels is between 5 and 10 dB, average the sound pressure level values
arithmetically and add 1 dB.
3. Maximum Variation over 10 dB. If the maximum variation exceeds 10 dB, average
according to the equation (6-1) below:
L = lOLogjol _
10
/
... (6-1)
6-2
-------
where
L = Average sound level (dB A) (or band average pressure level in decibels),
Li = Sound level (dB A) (or band sound pressure level in decibels) at the ith
position, and
n = Number of measuring stations.
10-POINT HEMISPHERE METHOD - SOUND POWER LEVEL
Theoretically, sound pressure levels measured over the entire surface of an imaginary
sphere surrounding the source should be used when calculating sound power levels. The
practical procedure for approximating the entire sphere is to select a number of points
located at the center of elements of equal area that are situated on the surface of an
imaginary hemisphere about the source. Figure 6-2 is a schematic of the microphone points
used for the 10-point hemisphere method, while Figure 6-3 shows the coordinates (relative
to the radius of the hemisphere) for the microphone positions. Sound power level is cal-
culated using Equation 6-2.
PWL = SPL + 20 Iog10 r + 0.5 dB ... (6-2)
where
PWL = sound power level in dB re 10"12 watts,
SPL = spatial average sound pressure level dB, and
r = radius of the hemisphere.
NATIONAL BUREAU OF STANDARDS METHODOLOGY
The National Bureau of Standards (NBS) investigated a measurement methodology
that would provide for the determination of A-weighted sound power level or the equivalent
A-weighted sound pressure level at a reference distance. The methodology makes use of
A-weighted sound level data acquired at a minimum of eight measurement positions disposed
on a curved surface surrounding the portable air compressor at a distance of 1 meter from
the surface of the machine. A-weighted sound data acquired at the eight measurement
positions are used to first calculate the average sound level of the test specimen and are then
6-3
-------
-X
-Y
.1
L0
7
= Height Above
Figure 6-2. Schematic Diagram of 10 Microphone Locations
at the Center of Elements of Equal Area on the
Surface of a Hemisphere about a Sound Source
6-4
-------
fll
9s
01
•
©
mi
•^^
POSITION
A
B
C
__ _ T(* 1 • ^ %-
F
G
H
1
•
X/R
0.158
0.775
0.738
0.775
0.158
- 0.257
-0.834
-0.834
-0.257
0.100
Y/R
0.898
0.550
- 0.067
- 0.603
- 0.961
-0.652
- 0.399
0.315
0.498
- 0.099
Z/R
0.410
0.313
0.671
0.193
0.224
0.713
0.381
0.452
0.828
0.990
Figure 6-3. Relative Coordinates for 10 Points of Hemisphere of Radius R
-------
combined with the area of the measurement surface to arrive at the A-weighted sound power
level of the machine. Reference 11 provides an in-depth discussion of the steps and
requisite calculation employed to determine A-weighted sound power level using the NBS
methodology.
As stated above, a minimum of eight measurement positions are employed in the
methodology, with provisions for measurements at eight additional positions should the •
range of the first eight sound level values exceed 8 dB. For conditions under which data
at the eight microphone positions suffice, one microphone is located near the center of
each of the four sides of the source, and four microphones are located above the top of
the source near the corners of the measurement surface. Figure 6-4 shows the microphone
array for the minimum (eight) measurement requirements. Table 6-1 lists the microphone
position coordinates for the eight measurement points of Figure 6-4. For situations
requiring additional measurements, Table 6-2 prescribes the coordinates of eight additional
measurement positions.
EPA PORTABLE AIR COMPRESSOR NOISE TEST PROCEDURE
In arriving at a compressor test procedure, EPA recognized the need for a common,
well known descriptor of portable air compressor noise to avoid possible confusion over
units of measurement by industry, state/local governments, and the public. Also recognized
was the need for a relatively simple method to accurately determine portable air compressor
noise that could be used both for product verification and enforcement.
Candidates for the proposed description of portable air compressor noise were:
• A-weighted sound pressure in dBA
• Sound power level in dB
• Sound power in milliwatts.
A-weighted sound pressure level in dBA was selected for several reasons, including its
utility and ease of acquisition. A-weighted sound pressure level can be measured directly
using common, readily available equipment. Thus, it is common to and widely used by
industry, the scientific community, state and local governments, and the general public to
assess human response to noise. This is in contrast to sound power level and sound power,
which cannot be measured but have to be calculated, typically from sound pressure level
data.
6-6
-------
Measurement surface
Zi
Reference parallelepiped
X
Plan View
Measurement surface
A
Reference parallelepiped
Measurement position
Figure 6-4. Microphone Placement - NBS Methodology
6-7
-------
Table 6-1
MICROPHONE POSITION COORDINATES - NBS METHODOLOGY*
Position Number
1
2
3
4
5
6
7
8
X
a
0
-a
0
al
~al
-~al
al
Y
0
b
0
-b
bl
bl
~bl
-bl
Z
hi
"i
hj
h!
greater than h
greater than h
greater than h
greater than h
Distance From
Reference Surface
r
r
r
r
r
r
r
r
*See Figure 6-4.
Source overall dimensions are L. W. H. corresponding to length, width and height
=j + r, = — + r,
hl =
ai =
Origin for the coordinate system is the point on the ground plane under the
geometric center of the source.
6-8
-------
Table 6-2
COORDINATES OF ADDITIONAL POSITIONS - NBS METHODOLOGY*
Position number
9
1C
11
12
13
14
15
16
X
a2
0
-a2
0
-1
-ai
-ai
ai
Y
0
bi
0
-bl
b
b
-b
-b
Z
hi
hi
hi
hi
Distance from
Reference Surface
r
r
r
r
r
r
r
r
_ 1 c
a2 ~ 2 (a + 2 ' < a
*See Figure 6-4.
6-9.
-------
By selection of the A-weighted sound level descriptor, the 10-point hemisphere and
far-field/near-field measurement methods for the acquisition of data to calculate sound
power level and sound power, respectively, were eliminated as candidates for the desired
test procedure. Their elimination resulted because the rigor involved in the methods is not
needed for the simple, direct measurement of A-weighted sound pressure level.
The remaining candidate for the desired test procedure was the CAGI/PNEUROP
measurement method. In reviewing this method, consideration was given to whether data
were needed at both the 1- and 7-meter microphone locations. EPA concluded that only
one set of data was needed, that at 7 meters. This conclusion was based on the fact that
the 1-meter measurement locations lie in the near field (see Section 7 of this document).
Although the near field data may be appropriate for regulatory use, they would not be
satisfactory for far-field extrapolation, as is often the case when it is desired to estimate
noise levels at residential positions some distance from the construction site (Section 7
discusses the problem in more detail). In other words, the 1-meter data are not as utilitarian
as are the 7-meter data.
Consequently, EPA selected the 7-meter microphone locations because:
• The microphone locations are in the far field.
• The data satisfactorily describe compressor noise.
• The data could be used for extrapolation with some degree of confidence.
The Agency also added an overhead microphone location to guard against compressor
design that would direct major sound energy upwards (this would be of significance to
persons residing in high-rise buildings adjacent to construction sites). Further, the need to
search for and report the maximum A-weighted sound pressure of the compressor was
eliminated, since data indicate that the maximum occurs at or near the four horizontal
points selected for measurement.
By selection of a modified but more simple CAGI/PNEUROP test method, little
education, if any, would be required on the part of industry, since the members of CAGI
are familiar with and currently use the CAGI/PNEUROP procedure.
The conditions and the measurement procedures requisite to measure the noise of
portable air compressors for the purpose of compliance with a noise standard are presented
in the following discussion.
6-10
-------
Test Site Description
Locations for measuring noise during noise compliance testing must consist of an open
site above a hard reflecting plane. The reflecting plane must consist of a surface of sealed
concrete or sealed asphalt and must extend 1 meter beyond each microphone location. No
reflecting surface such as a building, sign board, or hillside shall be located within 10 meters
of a microphone location.
Measurement Equipment
The following measurement equipment or its equivalent must be used during noise
standard compliance testing.
• A sound level meter and microphone system that conform to the requirements of
American National Standard Institute ANSI SI.4-1971, "Specification for Sound
Level Meters," as shown in the section concerning Type I sound level meter, and
the International Electrotechnical Commission (IEC) Publication No. 179. "Precision"
Sound Level Meters" regarding the sections concerned with microphone and ampli-
fier characteristics.
• A windscreen must be employed with the microphone during all measurements of
portable air compressor noise when the wind speed exceeds 11 km/hr. The wind-
screen shall not affect sound levels from the portable air compressor in excess of
± 0.5 dB.
• The entire acoustical instrumentation system, including the microphone and cable,
shall be calibrated before and after each test series. A sound level calibrator
accurate within ± 0.5 dB shall be used. A complete frequency response calibration
of the instrumentation over the entire range of 25 Hz to 11.2 kHz shall be performed
at least annually using methodology of sufficient precision and accuracy to determine
compliance with ANSI SI.4-1971 and IEC 179. This calibration shall consist, at a
minimum, of an overall frequency response calibration and an attenuator (gain
control) calibration plus a measurement of dynamic range and instrument electronic
noise.
• An anemometer or other device, accurate to within ± 10 percent, shall be used to
measure wind velocity.
• An indicator accurate to within ± 2 percent shall be used to measure portable air
compressor engine speed.
6-1
-------
• A gauge accurate to within ± 5 percent shall be used to measure portable compressor
air pressure.
• A metering device accurate to within ± 10 percent shall be used to measure the
portable air compressor compressed air volumetric flow rate.
Portable Air Compressor Operation
During noise standard compliance testing, the portable air compressor must be
operated at a design full speed with the compressor on load, delivering its rated output
flow and pressure. The discharged compressed air must be piped clear of the test site or
silenced.
Test Conditions
Noise standard compliance testing must be carried out under the following conditions:
• No rain or other preceipitation.
• No wind above 19 km/hr.
• No observer located within 1 meter, in any direction, of any microphone location,
or between the test unit and any microphone.
• Portable air compressor sound levels, at each microphone location, shall be a
minimum of 10 dB greater than the background sound level.
Microphone Locations
Five microphone locations must be employed to acquire portable air compressor
sound levels to test for noise standard compliance. A microphone must be located
7 ± 0.1 meters from the right-, left-, front-, back side and top of the test unit. The micro-
phone position to the right-, left-, front- and back side of the test unit must be located
1.5 ±0.1 meters above the reflecting plane. Figure 6-5 shows the microphone array.
6-12
-------
1.5m
Geometric Center
of Surface
of Interest
Microphone No. 1
Figure 6-5. Microphone Locations to Measure Portable Air Compressor Noise
Data Required
The following data must be acquired during noise standard compliance testing:
• A-weighted sound levels at one microphone location prior to operation of the test
unit and at all microphone locations during test unit operations.
• Portable air compressor engine speed.
• Portable air compressor compressed gas pressure.
• Portable air compressor flow rate.
6-13
-------
Calculation of Average Sound Levels
The average A-weighted sound levels from measurements at the specified microphone
locations must be calculated by the following method.
L= 10 login f4- ^ 10 (Li/10) j ...(6-3)
where:
L = average sound level, dBA, in decibels
LJ = sound level, dBA, in decibels at the i th location,
and
n = number of measurement position.
Presentation of Information
The following information must be reported:
• Background ambient sound level in dBA.
• Portable air compressor sound levels in dBA at each microphone location.
• Average portable air compressor sound levels in dBA.
N
• Portable air compressor compressed gas pressure, in kg/cm2 or psig.
• Portable air compressor compressed gas flow in m3/min or cfm.
• Portable air compressor manufacture, model and serial number.
• Acoustic instrumentation manufacturer, and model number.
The recommended data format is shown in Figure 6-6.
6-14
-------
Test Report Number
SUBJECT:
Manufacturer:
Rated Speed:
Model:
Serial No.:
rpm:
Configuration Identification:
Portable Air Compressor Identification No.:
TEST CONDITIONS:
Manufacturers Test Site Identification and Location:
Reflecting Plane Composition:
Rated Capacity: nr*/ min
Category Identification:
Build Date:
Operating Speed as Tested: Beginning of Test rpm
End of Test ^ ^ rpm
Air Pressure Supplied: kg/cm2. Ambient Wind Speed _
Actual How Rate: m3/min. Barometric Pressure
Temperature: °F
INSTRUMENTATION:
Microphone Manufacturer:
Sound Level Meter Manufacturer:
Calibrator Manufacturer:
Other and Manufacturer:
Model No.
Model No.
Model No.
Model No.
Serial No.
Serial No.
Serial No.
Serial No,
DATA:
Sound Levels,
Decibels
A-weighted
Background Sound
Level at Location 1
in Decibels
Location
1
2
3
4
5
Average
Sound
Level
TESTED BY:
REPORTED BY:
SUPERVISORY PERSONNEL:
DATE:
DATE:
TITLE:
TITLE:
Figure 6-6. Recommended Portable Air Compressor Noise Data Sheet
6-15
-------
Section 7
PORTABLE AIR COMPRESSOR NOISE
The basic elements of all noise problems are the (1) source, (2) path, and (3) receiver.
Studies have been conducted on all three of these elements. The first two are discussed in
this and the following section, and the third is discussed in Section 10.
Study of the portable air compressor as a source included evaluation of:
• Overhead noise levels of unsilenced and silenced compressors.
• Noise levels of unsilenced and silenced portable air compressors ranging from 85 to
1200 cfm capacity.
• Repeatability of compressor noise measurements.
• Noise directivity of unsilenced and silenced compressors.
• Compressor sound power levels.
• Low frequency compressor noise.
• Identification of major noise sources associated with portable air compressors (see
Section 8).
• Degree of quieting with application of present technology (see Section 8).
Study of the propagation path included the following considerations:
• Ground reflections
• Path discontinuities
• Calculation of far field data from near field data.
7-1
-------
OVERHEAD NOISE
To increase the data base and to provide data to assess the noise characteristics of
portable air compressors, noise measurements were made of 4 gasoline and 19 diesel
powered compressors ranging in capacity from 85 to 1200 cfm. Table 7-1 lists information
about the units and the test method employed. As indicated in the table, both silenced and
standard versions of some compressors were evaluated, and, in some cases, the compressor
housing doors were purposely left open.
The most commonly used portable air compressor measurement scheme, the CAGI/
PNEUROP method (see Section 6), does not presently include measurement of sound above
portable air compressors. Since engine exhaust often is directed upward, noise radiating in
this direction could be of significance, particularly to persons in offices and apartments
located above operating compressors. Consequently, measurements were made of noise
radiating upward and were compared with that radiated to the side of compressors.
Table 7-2 lists the measured CAGI/PNEUROP average and overhead noise levels for
the 26 compressor tests. The last column in this table is the difference between these two
levels. Figure 7-1 shows a histogram of these differences.
For 4 of 26 compressors, the overhead noise level is greater than the horizontal noise
level. All other models show the overhead direction to be quieter than, or equal to, hori-
zontal radiated noise. The mean difference in Figure 7-1 shows the upward-directed noise
to be 0.6 dBA less than the CAGI/PNEUROP calculated level not including an overhead
measurement point. The spread in the data; however, results in a standard deviation of
2 dBA.
Of the four compressors that are significantly noisier overhead, two are for the same
model (doors open and closed) with a relatively inefficient exhaust muffler. The other two
are for silenced units similar to companion products with overhead sound levels significantly
less than the sideline average. Consequently, if we momentarily ignore these results as
atypical or as possible measurement error, the statistics of the remaining 20 are computed.
The following values result:
• Mean: -1.5 dBA
• Standard deviation = 1.1 dBA
Thus, for this group of compressors, the overhead noise level is about 1.5 dBA less than in
other directions.
7-2
-------
Table 7-1
COMPRESSORS TESTED AND TEST METHODOLOGY EMPLOYED
Manufacturer
Atlas Copco
Atlas Copco
Atlas Copco
Atlas Copco
Atlas Copco
Atlas Copco
Atlas Copco
Atlas Copco
Gardner- Denver
Gardner-Denver
Card ne r- Denver
Ingersoll- Rand
Inge rsoll- Rand
Ingersoll- Rand
Ingersoll- Rand
Ingersoll- Rand
Ingersoll- Rand
Ingersoll- Rand
Ingersoll- Rand
Ingersoll- Rand
Jaeger
Jaeger
Jaeger
Jaeger
Worth! ngton
Worthington
Model
ST-48
ST-95
VSS-170 Dd
VT-85 Dd
VS-85 Dd
VSS-125 Dd
STS-35 Dd
VSS-170 Dd
SPWDA/2
SPQDA/2
SPHGC
DXL 1200
DXL 1200
(doors open)
DXL900S
DXL 900S
DXL GUI 050
DXL900S
DXL 900S
DXL 900
DXL 750
A
A (doors open)
E
E (doors open)
160 G/2 QT
750-QTEX
Silenced
or Standard
Standard
Standard
Silenced
Standard
Silenced
Silenced
Silenced
Silenced
Silenced
Silenced
Silenced
Standard
Standard
Silenced
Silenced
Standard
Silenced
Silenced
Standard
Standard
Standard
Standard
Standard
Standard
Silenced
Silenced
Type
Engine
Diesel
Diesel
Diesel
Gas
Gas
Diesel
Diesel
Diesel
Diesel
Diesel
Gas
Diesel
Diesel
Diesel
Diesel
Diesel
Diesel
Diesel
Diesel
Diesel
Gas
Gas
Gas
Gas
Gas
Diesel
Type
Compressor
Reciprocal
Reciprocal
Reciprocal
Reciprocal
Reciprocal
Reciprocal
Reciprocal
Reciprocal
Rotary-Screw
Rotary- Screw
Rotary-Screw
Rotary- Screw
Rotary-Screw
Rotary-Screw
Rotary- Screw
Rotary- Screw
Rotary-Screw
Rotary- Screw
Rotary- Screw
Rotary-Screw
Rotary-Screw
Rotary- Screw
Vane
Vane
Vane
Rotary-Screw
Serial No.
51232751
51-274977
51-23507-
ARP203149
ARP203903
51-345060
ARP550924
51-235072
635851
608227
629717
74430
74430
73693
74050
75613
74051
740471
75847
77380
RS-32189
RS-32189
RC-32032
RC-32032
821-478
848-019
Test Condition
(cfm, psi)
160,100
330, 105
170, 850
85,100
85,100
125,100
125, 100
170,100
1200, 000
750, 000
185,000
1200,125
1200,125
900, 125
900, 125
1050, 125
900, 125
900, 125
900, 125
750, 125
175,100
175,100
85, 100
85,100
160,100
750,100
Test Method
CAGI/PNEUROP
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
Overhead
Measurement
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
10 Point
Hemispherical'
X
5
X
X
X
X
X
4
Diagonal
X
X
X
u>
1. ISO 2151-1972 Method (See Figure 6. I)
2. ISO 2151-1972 Method plus A 7 meter overhead point
3. See Figure 6.9 and 6.10
4. Measurements were made at diagonal locations at 0 meters
5. Measurements were made for the compressor operating at idle and full power
-------
Table 7-2
COMPARISON OF CAG1/PNEUROP AVERAGE SIDE
WITH OVERHEAD NOISE LEVELS
No.
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
Manufacturer
Atlas Copco
Atlas Copco
Atlas Copco
Atlas Copco
Atlas Copco
Atlas Copco
Atlas Copco
Atlas Copco
Worthington
Worthing ton
Ingersoll- Rand
Ingersoll^ Rand
Ingersoll- Rand
Inger s oil- Rand
IngersoU-Rand
Ingersoll- Rand
Ingersoll- Rand
Ingersoll- Rand
Ingersoll- Rand
Gardner-Denver
Gardner- Denver
Gardner-Denver
Jaeger
Jaeger
Jaeger
Jaeger
Model
ST-48
ST-95
VSS-170 Dd
VT-85 Dd
VS-85 Dd
VSS-125 Dd
STS-35 Dd
VSS-170 Dd
160 G/2 QT
750-QTEX
DXL 1200
DXL 1200*
DXL 900S
DXL 900S
DXL CU1050
DXL 900S
DXL 900S
DXL 900
DXL 750
SPWDA/2
SPQDA/2
SPHGC
A
A*
E
E*
(A)
CAGI/
PNEUROP
84
80.5
71
82.5
75.5
70
73
71
75
75
94.5
96.5
77.5
75.5
91
76
75.5
90.5
88
74
78.5
77.5
88.5
89
81.5
82
(B)
Overhead
83
79.5
68
79
76
72.5
77
68.5
72
73.5
75
74.5
89
73.5
74
89
88
73
78
75
88
89.5
84
85
B-A
-1
_i
-3
-3.5
0.5
2.5
4
-2.5
-3
-1.5
-2.5
-1
-2
-2.5
-1.5
-1.5
0
-1
-0.5
-2.5
-0.5
0.5
2.5
3
*Doors open
7-4
-------
£
2 3
-T
-
"S
2
Median: - 1 dB(A)
Mean: -0.6dB(A)
a = 2.0dB(A)
-5 -4 -3 -2-10 2
dB(A) Difference
[OverheacHVIinus CAGI/PNEUROP]
Figure 7-1. Comparison Between Overhead Noise Level
and CAGI/PNEUROP Level
PORTABLE AIR COMPRESSOR NOISE LEVELS
New Data
As discussed previously, measurements were made of a total of 23 portable air
compressor types. Tables 7-3 and 14 list noise levels of the standard and silenced com-
pressors, respectively, while Figure 7-2 shows a plot of noise versus cfm capacity. From
review of the data in the tables and figures, the following may be concluded:
• Noise levels of both standard and silenced compressors increase with increasing com-
pressor capacity, with noise of the standard units increasing at a more rapid rate.
• Noise levels of standard compressors range in level from 81.4 to 92.6 dBA at 7 meters.
• Noise levels of silenced compressors range in level from 70.1 to 78.2 dBA at 7 meters.
• Silenced compressors are on the average 10 to 15 dBA quieter than standard units.
7-5
-------
Table 7-3
NOISE LEVELS OF STANDARD COMPRESSORS
USING THE CAG1/PNEUROP MEASUREMENT METHOD
Manufacturer
Atlas Copco
Atlas Copco
Atlas Copco
Jaeger
Jaeger
Ingersoll-Rand
Ingersoll-Rand
Ingersoll-Rand
Ingersoll-Rand
Model
VT85Dd
ST-48
ST-95
E
A
DXL750
DXL900
DXLCU1050
DXI1200
S/N
ARP203149
51-232751
51-274977
RC32032
RS32189
77380
75847
75613
74430
Cfm
85
160
330
85
175
750
900
1050
1200
Average Noise Level (dBA)
1 meter
94.8
96.6
91.9
92.5
98.9
98.6
97.9
100.8
103.0
7 meter*
81.4
83, "
80.2
81.5
88.2
87.7
89.9
90.2
92.6
* Includes overhead measurement point
-------
Table 7-4
NOISE LEVELS OF SILENCED COMPRESSORS
USING THE CAGI/PNEUROP MEASUREMENT METHOD
Manufacturer
Atlas Copco
Atlas Copco
Atlas Copco
Atlas Copco
Worthington.
Gardner-Denver
Gardner-Denver
Worthington
Inger soil- Rand
Inge rs oil- Rand
Ingers oil- Rand
Inger soil- Rand
Gardner-Denver
Models
VS85
STS35Dd
VSS125Dd
VSS170Dd
160G/2QT
SPHGC
SPQDA/2
750QTEX
DXL 900S
DXL 900S
DXL 900S
DXL 900S
SPWDA/2
S/N
ARP203903
ARP550924
51-345060
51-235072
821478
629717
608227
848-019
73693
74050
74051
740471
635851
Cfm
85
125
125
170
160
185
750
750
900
900
900
900
1200
Average Noise Level (dBA)
1 meter
89.0
85.5
81.0
83.9
84.5
87.0
86.1
84.0
82.4
82.0
83.1
82.4
84.1
7 meter*
75.5
73.5
70.1
70.2
74.2
77.1
78.2
74.7
76.0
75.1
75.3
75.0
73.7
*Includes overhead measurement point
-------
•••
100
Silenced Compresso
1—
O Standard Units
100
300
900
1100
500 700
Capacity-cfm
Figure 7-2. Noise of Standard and Silenced Compressors as a Function of Capacity - CFM
1300
-------
Existing Data
Manufacturers supplied EPA (Contractor BBN) with noise data at 7 meters for 194
compressor models. Table 7-5 lists the data in terms of compressor capacity, engine type,
and standard/quieted units. Also shown in the table is the number and percent of units
below a particular noise level.
In summary, the data shows:
• Standard models of gas engine powered compressors range in noise level from 71.0
to 92.0 dBA with a mean value of 82.8 dBA.
• Silenced models of gas engine powered compressors range in noise level from 72 to
81 dBA with a mean value of 76.1 dBA.
• Standard models of diesel engine powered compressors of less than 251 cfm capacity,
range in noise level from 80.0 to 93.0 dBA with a mean value of 84.7 dBA.
• Silenced models of diesel engine powered compressors, of less than 251 cfm capacity,
range in noise from 70.0 to 88.0 dBA with a mean value of 75.5 dBA.
• Standard models of diesel engine powered compressors, of greater than 250 cfm
capacity, range in noise level from 84.0 to 102.0 dBA with a mean value of 91.7 dBA.
• Silenced models of diesel engine powered compressors of greater than 250 cfm
capacity, range in noise level from 74.0 to 88.0 dBA with a mean value of 77.7 dBA.
CORRELATION OF DATA
Data acquired by EPA, using the CAGI/PNEUROP method were compared with available
manufacturer's data. Figure 7-3 presents a histogram of the compressor in which good corre-
lation is shown, i.e., both mean and median ratios are approximately zero.
To assess the correlation of noise levels of compressors of a particular model, measure-
ments were made of four units of 900 cfm capacity. Table 7-6 summarizes the tests results
and shows that noise levels correlate to within 1.5 dB at individual measurement positions
and to within 1.0 dB on the average.
7-9
-------
Table 7-5(a)
PERCENT AND NUMBER OF PORTABLE AIR COMPRESSORS
WITH NOISE LEVELS NOT IN EXCESS OF A PARTICULAR VALUE*
(Major Category of Portable Air Compressors by Capacity and Type of Engine)
Gasoline Engine, All Capacities**
Standard Mode
dBA Level
71.0
72.0
73.0
74.0
75.0
76.0
77.0
78.0
79.0
80.0
81.0
82.0
83.0
84.0
85.0
86.0
87.0
88.0
89.0
90.0
91.0
92.0
Percent of
Cumulative
Units Below
0.0
3.12
3.12
9.37
9.37
12.50
12.50
18.75
18.75
21.87
28. 12
28. 12
34.37
50.00
62.50
75.00
81.25
90.26
90.62
93.75
96.87
100.00
s
Number of
Units Below
0
1
1
3
3
4
4
6
6
7
9
9
11
16
20
24
26
29
29
30
31
32
Quieted Models
dBA Level
72.0
73.0
74.0
75.0
76.0
77.0
78.0
79.0
80.0
81.0
Percent 01
Cumulative
Units Below
0.0
11.54
15.38
26.92
50.00
65.38
69.23
84.62
92.31
100. 00
Number of
Jnits Below
0
3
4
7
13
17
18
22
24
26
Mean: 82. 8 dBA***
Standard Deviation: 4. 92 dBA***
Mean: 76.1 dBA***
Standard Deviation: 2. 40 dBA***
* Average sound pressure level in dBA at 7m according to the recommended
measurement practice of ISO 2151-1972. Manufacturers were sometimes
imprecise in defining the noise data submitted to BBN. BBN has treated this
data as an average of noise level for a model based on testing a number of
units.
** BBN did not document in its report the manufacturers whose model data is
included in the 194 data points reported.
*** The mean is a simple average of model noise data. Data is not available to
weight by relative model unit volume sold. Partial weighting schemes by
capacity and/or manufacturer were not utilized.
7-10
-------
Table 7-5(b)
PERCENT AND NUMBER OF PORTABLE AIR COMPRESSORS
WITH NOISE LEVELS NOT IN EXCESS OF A PARTICULAR VALUE*
(Major Category of Portable Air Compressors by Capacity and Type of Engine)
Diesel engine, below 251 cfm capacity**
Standard models
dBA Level
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
Percent of
Cumulative
Units Below
0.00
2.86
2.86
20. 00
28.57
34.29
54.29
62.86
74.29
77.14
85.7
88.57
88.57
97.17
100.0
Number of
Units Below
0
1
1
7
10
12
19
22
26
27
30
31
31 .
34
35
Mean: 84. 7 dBA***
Standard Deviation: 3. 0 dBA***
(Quieted models
dBA Level
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
Percent of
Cumulative
Units Below
0.00
12.12
12.12
12.12
18.18
21.21
48.48
54.54
66.67
69.70
75.76
78.79
81.82
87.88
93.94
96.97
96.97
96.97
96.97
100.00
Mean: 75. 5 dBA***
Number of
Units Below
0
4
4
4
6
7
16
18
22
23
25
26
27
29
31
32
32
32
32
33
Standard Deviation: 5. 14 dBA***
Average sound pressure level in dBA at 7m according to the recommended
measurement practice of ISO 2151-1972. Manufacturers were sometimes
imprecise in defining the noise data submitted to BBN. BBN has treated
this data as an average noise level for a model based on testing a number
of units.
BBN did not document in its report the manufacturers whose model data is
included in the 194 data points reported.
The mean is a simple average of model noise data. Data is not available to
weight by relative model unit volume sold. Partial weighting schemes by
capacityand/or manufacturer were not utilized.
7-11
-------
Table 7-5(c)
PERCENT AND NUMBER OF PORTABLE AIR COMPRESSORS
WITH NOISE LEVELS NOT IN EXCESS OF A PARTICULAR VALUE*
(Major Category of Portable Air Compressors by Capacity and Type of Engine)
Diesel engine, above
f
dBA Level
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
standard mooeis
Percent of
Cumulative
Units Below
0.00
2.33
9.30
9.30
11.63
21.21
23.26
37.21
46.51
53.49
62.79
74.42
76.74
76.74
81.40
88.37
93.02
97.67
97.67
100.00
Number of
Units Below
0
1
4
4
5
7
10
16
20
23
27
32
33
33
35
38
40
42
42
43
Mean: 91. 7 dBA***
Standard Deviation: 4. 02 dBA***
250 cfm capacity**
Oiiiotorl mnriels
^ «
dBA Level
73
74
75
76
77
78
79
80
81
82
8"3
84
85
86
87
88
Percent of
Cumulative
Units Below
0.00
6.25
9.38
21.88
46.88
56.25
62.50
65.63
68.75
75.00
78.13
81.25
87.50
90.63
96.88
100.00
Number of
Units Below
0
2
3
7
15
18
20
21
22
24
25
26
28
29
31
32
Mean: 77. 7 dBA***
Standard Deviation: 3. 87 dBA***
Average sound pressure level in dBA at 7m according to the recommended
measurement practice of ISO 2151-1972. Manufacturers were sometimes
imprecise in defining the noise data submitted to BBN. BBN has treated
this data as an average noise level for a model based on testing a number
of units. , , .
BBN did not document in its report the manufacturers whose model data is
included.in the 194 data points reported.
The mean is a simple average of model noise data. Data is not available to
weight by relative model unit volume sold. Partial weighting schemes by
capacity and/or manufacturer were not utilized.
7-12
-------
s 4
c
_
:
L
Median: 0 dB A
Mean: -0.1 dB A
0 = 1.5dB A
-5 -4 -3
NOTE: Silenced Models Only
-2 -1
Sound Level Difference, dB A
(Mfgr. Minus Survey)
Figure 7-3. Comparison of Manufacturer Supplied Data with Survey Data
NOISE DIRECTIVITY
Noise levels measured during compressor operation at rated power were analyzed to
assess noise directivity around portable air compressors. Table 7 7 lists J3A levels, average
dBA levels, and the maximum directivity factor associated with the six types of compressors.
The data were acquired using the 10-point hemisphere measurement method and show
little variance in noise level from position to position, indicating little directivity of noise.
Figure 7-4 shows a polar plot of noise at azimuthal locations every 30 degrees in the
horizontal plane around a compressor. Again, little directivity is shown.
PORTABLE AIR COMPRESSOR SOUND POWER LEVEL
Though portable air compressors have been and are currently characterized in terms
of sound pressure level at a specified distance, thought was given to the possible character-
ization in terms of sound power. Of prime consideration was a feasible measurement
methodology. Accordingly, portable air compressor sound power levels were calculated
7-13
-------
Table 7-6
REPEATABILITY OF NOISE LEVELS OF FOUR MODELS
THE INGERSOLL RAND DXL 900S COMPRESSOR
Serial No.
73693
74050
74041
740471
Measurement Positions**
7
73
72.5
73
72
8
76.5
75.5
76.5
76.5
9
78.5
76.5
77
77
10
77
76.5
76.5
75.5
11*
75
74.5
73.5
74
Average dBA Level
76.0
75.1
75.3
75.0
* Overhead Position
** See Figure 6-1
-------
Table 7-7
AIR COMPRESSOR NOISE DIRECTIVITY
Micropnone
Location*
A
c
E
F
H
T
J
Average dBA
EH
O •
(N
O
o
10
rH
O
4J
C
•H
•P
0
o
I
en
en
o
u
0
u
M
rt
•P
X
9-1
O
o
m
c
O
tr>
C
-P
0
o
in
o
•H
U
X
Q
T)
«
,_!
rH
0
(0
0)
c
H
en
0
0
X
Q
13
C
«
rH
rH
0
Cfl
tn
C
H
Sound Level, dBA
77
77
77
77
78
77
78
77
77
76
77.1
Maximum Directivity
Factor ** 1.23
71
75
72
72
72
71
71
72
71
70
71.7
2.14
72
72
73
73
71
71
72.5
72.5
72
72.5
72.2
1.22
92
94.5
93
94.5
94.5
93
91
91.5
92
89
92.5
1.58
77.5
76.5
80
75.5
78
80.5
81
81
79
78
78.9
1.62
€N
"^s.
8
CU
CO
M
(U
C
fl)
Q
M
Q)
£
T)
i-l
O
81
80.5
77
78.5
79
79.5
80.5
81
80.5
77
79.5
1.43
* See Figure 6-2 and 6-3
** Maximum directivity factor = antilogy
7-15
L -L
max
-------
330
300
240
210
60°
120"
Figure 14. Horizontal Directivity of Ingersoll-Rand
(DXL 900 S) Compressor
7-16
-------
using data acquired by the CAGI/PNEUROP method and by a method developed by the
National Bureau of Standards. These levels were then compared with levels calculated from
data acquired by more conventional means; i.e., by microphones located at the center of
surfaces of equal area on the surface of an imaginary hemisphere about the source. 1 he
distinct differences between the measurement methodologies evaluated are the microphone
placement in the far field (7 meters) for the CAGI/PNEUROP methodology and in the near
field (1 meter) for the NBS methodology.
CAGI/PNEUROP Measurement Methodology
The results presented in Table 7-8 show that power levels calculated from the CAGI/
PNEUROP 4- and 5-point data compare well to those calculated from data obtained using the
more precise 10-point hemispherical measurement method. An average difference of only 0 6 dB
was found in each case. These results occurred primarily because the compressors tested were
To ery directive. In the extreme case of a completely nondirective compressor all methods would
yield exactly the same results. In fact, only one sound level measurement would be required.
NBS Measurement Methodology
NBS performed an experimental study to assess the validity of using "near field" mea-
surements of sound pressure levels to predict the sound power level of portable air compressors.
The experimental program consisted of the measurement of the sound pressure leves of 17
portable air compressor models. Measurements were made on two hypothetical surfaces, a
large and a small surface, surrounding the test units.
The larger surface yielding the "far field" measurement data was a hemisphere of a
fixed 7-meter radius. Sound pressure levels were measured at a total of 84 positions. This
was accomplished by rotating an array of seven microphones through 12 different position.
Figure 7-5 shows the basic seven microphone array and lists the coordinates of the 84 micro-
phone positions.
The smaller measurement surface, which yielded the "near field" data, consisted of a hypo-
thetical rectangular box surrounding the source at a distance of 1 meter from the surfaces of each
of the 17 portable air compressor models tested. Figure 7-6 shows the typical microphone array
employed. Further details regarding the microphone arrays appears in Reference 11.
Table 7-9 presents a comparison of portable air compressor sound power levels calcu-
lated from near and far field data for 17 models of compressors. Shown fa the excellent
correlation between the data, with the average difference being 0.44 dB. Accordingly, it is
7-17
-------
Table 7-8
SOUND POWER LEVEL COMPARISONS
Compressor
Atlas Copco
VSS 170
Worthington
160 QT
Worthington
750-QTEX
Lager soil- Rand
DXLCU 1050
Ihgersoll- Rand
DXL 900S
Gardner-Denver
SPQDA/2
(Full Power)
Gardner- Denver
SPQDA/2
(Idle)
PWL*
(4pU)
(dBA)
96.4
100.9
99.9
117.4
102.2
' 105.0
96.6
PWL*
(5pt.)
(dBA)
96.3
100.5
99.9
117.2
102.1
105.1
97.1
PWL*
(10 pt. )
(dBA)
96.7
102.1
100.2
117.5
103.9
104.5
97.5
™ho
minus
PWL.
4
0.3
1.2
0.3
0.1
1.7
-0.5
0.9
PWL10
minus
PWL5
0.4
1.6
0.3
0.3
1.8
-0.6
0.4
*PWL = Sound power level
7-18
-------
Cables to Pole
Support
MICROPHONE
NO.
1
2
3
4
5
6
7
ANGLE 0/
(degrees)
14.2
35.1
65.5
90.0
47.6
24.2
4.7
X,
Z,
(metres)
6.79
5.71
2.89
0.00
4.71
6.38
6.98
1.73
4.03
6.33
7.00
5.18
2.88
.58
where in degrees =
0, 30, 60, 90, 120, 150, 180
210, 240, 270, 300, 330
Figure 7-5. Far-Field Measurement Microphone Array (p: 1.5 cm = 1 m)
-------
to
o
1 m
Figure 7-6. Representative Near-Field Measurement Positions
-------
Table 7-9
COMPARISON OF PORTABLE AIR COMPRESSOR SOUND POWER LEVELS
CALCULATED FROM NEAR AND FAR FIELD DATA
Compressor
cftn
185
150
160
150
200
100
160
125
365
900
100
175
175
185
175
85
150
Characteristic
Size (Length, Width,
Height) Meters
1.97x1.28x1.40
1.73x0.77x1.47
2.07x1.14x1.77
1.71x1.24x1.77
1.83x0.96x1.50
1.52x0.67x1.42
2.10x1.28x1.78
1.78x1.30x1.85
3.66x1.82x2.14
4.29x2.19x2.51
1.78x1.22x1.37
2.70x1.29x1.43
2.70x1.29x1.43
2.70x1.29x1.43
1.99x1.27x1.45
1.96x1.10x1.34
1.93x1.24x1.36
Far Field Sound
Power Level, dBA
Re 10 Watts
105.1
110.8
106.8
113.1
108.9
109.0
106.9
103.1
98.7
104.8
107.7
101.1
101.4
99.3
108.7
101.1
103.6
Near Field Sound*
Power Level, dBA
Re 10 Watts
103.9
110.8
106.5
113.8
107.5
108.4
107.0
103.0
97.1
105.8
108.2
100.6
99.1
98.7
110.1
101.8
103.6
Difference, dBA
Far Field Minus
Near Field
1.2
0
0.3
0.7
1.4
0.6
0.1
0.1
1.6
1.0 •
-0.5
0.5
2.3
0.6
-1.4
-0.7
-0.6
* One of eight calculations using near field data (see reference 11 for additional calculations/comparisons).
This particular listing uses data at points corresponding (approximately) to the eight point measurement
array of ISO draft standard DIS 3744 and DIS 3746.
-------
concluded that portable air compressor sound power levels may be accurately calculated
from data measured on a surface 1 meter from the compressor enclosure using the NBS
measurement methodology calculation scheme.
LOW FREQUENCY NOISE
The A-weighting network of sound level meters attenuated low-frequency noise; e.g.,
-39.4 dB, -26.2 dB, -16.1 dB, and -8.6 dB at frequencies of 31.5 Hz, 63 Hz, 125 Hz, and
250 Hz, respectively [18]. As such, great differences can result between A-weighted levels
and the unweighted (relatively speaking) C-weighted levels. The significance of this is the
possibility that while noise suppression methods may reduce a compressor's A-weighted noise
rating, the C-weighted level could conceivably remain the same or could, in fact, increase.
Though A-weighted sound level decreases might adequately reduce health and welfare
impact, C-weighted noise control may be desirable as well to preclude the escalation of
overall unweighted compressor noise.
Tables 7-10 and 7-11 show dBC/dBA differences for standard and silenced portable air
compressors, respectively. As shown, dBC/dBA differences up to 28 dB are noted for silenced
models. Figures 8-1 and 8-2 give insight into the cause for the greater dBC/dBA difference for
the silenced models. In the figures it is shown that a lower dBA level for the silenced unit
has been achieved by a shift of peak sound levels to the low-frequency range. Note that
while the A-weighted sound level of a compressor has been reduced by 5 dB (standard to
silenced) the C-weighted value has been reduced by only 1 dB as a result of the different
weighting characteristics of the A and C networks.
Since (1) an A-weighted noise reduction does not necessarily imply an attendant C-
weighted reduction and (2) there may arise a need to control the C-weighted level of com-
pressor noise, Figure 7-7 was prepared from the data of Tables 7-10 and 7-11 to give insight
into achievable C-weighted levels. The line in Figure 7-7 represents a best-fit curve through
the data points and indicates that a dBC minus dBA limit of 20 dB would be a reasonable
control limit.
ACOUSTIC VALUE OF PORTABLE AIR COMPRESSOR DOORS
At a construction job site, portable air compressor equipment compartment doors are
sometimes left open because of the operators' misguided intent of furnishing more engine
and compressor cooling. Actually, portable air compressors are designed to provide adequate
cooling with the access doors closed. Since closed access doors eliminate a direct line of
sight to the engine (which is the major source of noise), an escalation of portable air com-
pressor noise is expected to occur when the doors are left open.
7-22
-------
Table 7-10
COMPARISON OFdBA LEVELS WITH dBC LEVELS OF
STANDARD PORTABLE AIR COMPRESSORS
Manufacturer
Atlas Copco
Atlas Copco
Atlas Copco
Ingersoll- Rand
Ingersoll- Rand
Ingersoll- Rand
Ingersoll- Rand
Jaeger
Jaeger
Model
VT85Dd
ST-48
ST-95
DXL750
DXL900
DXLCU1050
DXL1200
E
A
S/N
ARP203149
51-232751
51-274977
77380 V
75847
75613
74430
RC32032
RS32189
cfm
85
160
330
750
900
1050
1200
85
175
dBC Level Minus
dBA Level* dB
11
8.5
9.5
5
3
7
3
12.5
13.5
-jj
to
* Average levels at 7 meters
-------
Table 7-11
COMPARISON OF dBA LEVELS WITH dBC LEVELS
OF SILENCED PORTABLE AIR COMPRESSORS
Manufacturer
Atlas Copco
Atlas Copco
Atlas Copco
Atlas Copco
Worthington
Gardner-Denver
Gardner-Denver
Worthington
Ingersoll- Rand
Ingersoll-Rand
Ingersoll- Rand
Ingersoll-Rand
Gardner-Denver
Model
VS85
STS35Dd
VSS125Dd
VSSlTODd
160G/2QT
SPHGC
SPQDA/2
750QTEX
DXL 900S
DXL 900S
DXL 900S
DXL 900S
SPWDA/2
S/N
ARP203903
ARP550924
51-345060
51-235072
821478
629717
608227
848-019
73693
74050
74051
740471
635851
cfm
85
125
125
170
160
185
750
750
900
900
900
900
1200
dBC Level
Minus dBA Level*
dB
16.0
23.5
28.0
21.0
15.0
12.0
7.5
10.5
7.7
6.9
7.8
7.5
10.0
*Average levels at 7 meters
-------
i '
! •.
00
a
0
Cfl
•g
"J
&
0)
+30
+20
+10
c
I -10
2>
'•
6
8
Silenced Units
Standard Units
100
300
500
700
Capacity cfm
900
1100
1300
Figure 7-7. Portable Air Compressor C-Weighted minus A-Weighted Levels
Versus Capacity - CFM
-------
Six tests were conducted (three of the standard units and three of silenced units) to
assess the magnitude of escalation of portable air compressor noise due to opening the access
doors. Table 7-12 presents the results of the tests of the standard units. Shown is a noise
increase of up to 5 dB.
Table 7-12
EFFECT ON STANDARD PORTABLE AIR COMPRESSOR
NOISE OF OPENING THE EQUIPMENT COMPARTMENT
ACCESS DOORS
Manufacturer
Ingersoll-Rand
Jaeger
Jaeger
Model
DXL 1200
A
E
A-Weighted Increase, dBA*
5.0
1.5
1.5
* Difference in level at the right side of the unit between door open and closed
position.
Table 7-13 lists the results for the silenced units. Shown is an increase up to 12 dBA
when the access door of the Worthington 750 QTEX was left open.
Table 7-13
EFFECT ON SILENCED PORTABLE AIR COMPRESSOR NOISE
OF OPENING THE EQUIPMENT COMPARTMENT ACCESS DOOR
Manufacturer
Worthington
Atlas Copco
Worthington
Model
160 QT
VSS170Dd
750 QTEX
A-Weighted Increase, dBA
5.0
11.0
12.0
7-26
-------
In view of the data of Tables 7-12 and 7-13, portable air compressor equipment com-
partment access doors must remain closed during compressor operation to preclude acoustic
degradation.
PORTABLE AIR COMPRESSOR NOISE PROPAGATION
If the propagation of sound from compressors to points more than several hundred feet
distant is of concern, then meteorological factors, i.e., wind, temperature, humidity, and
precipitation, may play a significant role. In addition, obstacles and variations in ground
cover may also be important. For shorter distances, the propagation may be complicated by
interference phenomena between the sound waves radiating directly from a source and those
reflected from nearby surfaces, especially the ground [ 19, 20, 21 ].
Ground Reflections
Contributions arising from constructive/destructive interference between direct sound
waves and sound waves reflected from the ground plane at measurement positions have been
evaluated. Figure 7-8 shows A-weighted noise measured 7 meters away from a compressor
at various heights above the ground. While sound levels may vary in some 1/3 octave-bands
as much as 7 dBA from one height to another, the variation in overall sound level is ± 1 dBA
from the central position.
The effect of ground reflections on the measured sound levels at the 7-meter positions
appear to be "averaged out" by the spatial distribution of the individual noise-generating
components of the compressor. Thus, it is concluded that at 7 meters ground reflections do
not modify the overall measured sound levels.
Path Discontinuities
As compressor noise propagates away from the source, propagation path discontinuities
can affect the sound waves. The six configurations in Figure 7-9 comprise those typical at
construction sites. The half space shown in this figure represents the area surrounding a com-
pressor during testing per ISO-2151-1972 or when used during construction in residential or
light-industrial areas. Sound propagating in a half space is subject to the interference effects
discussed previously. When a compressor in a residential or light-industrial area is next to a
building, the buildings usually are far enough apart to be described by the "L" space in
Figure 7-9. Anderson [22] reported that sound propagates in an "L" cross section as it does
in free space. The sound level at a point in an "L" space is expected to be on the order of
7-27
-------
oo
0.6 m Above Ground
1.8 m Above Ground
1.2 m Above Ground
•T /
*'"'\ /
»: ! .••'%.
Worthington 750 Compressor
At Full Power (2100 rpm)
I I I I I I I I I 1
500
1000
2000
4000
8000
16,000
One-Third Octave-Band Center Frequency (Hz)
*Sound was pref iltered by A -weighing network prior to 1/3 octave band analysis.
Figure 7-8. Effect of Microphone Height on A-Weighted Sound at 7 Meters
-------
JUL
HALF SPACE
(NO CORRECTION)
BUILDING
"L"SPACE
(ADD 2 dB)
BUILDING
BUILDING
w////my/u
"U"SPACE
(ADD4dB)
n
VAULT
(ADDIOdB)
BUILDING
BARRIER
BARRIER
(SUBTRACT 17 dB)
v.
BUILDING
BARRIER
W/////,
I
(SUBTRACT 20 dB)
BARRIER AND PIT
Figure 7-9. Configurations of Locations of Compressors at Construction
Sites (Corrections are for half space sound levels measured at
7 meters from the machine surface.)
7-29
-------
3 dB higher than the, sound level measured at the same point in a free field over a reflecting
plane, because the sound energy is concentrated in a smaller volume in an "L" space than in
a half space. Francois and Fleury [19] measured a corresponding 2-dB increase in compressor
noise in an "L" space.
The "U" space in Figure 7-9 is representative of city "canyons," formed by a street or
alley and the vertical walls of nearby buildings. Appendix A of Reference 10 discusses the
propagation of sound in city canyons in more detail and also includes the results of calcula-
tions carried out using an extension of the theory of Weiner, et al [23]. The theory shows
that a nondirectional source produces sound levels in a typical city canyon that are 6 dB
higher 100 feet from the source than the levels present in a half space. Francois and
Fleury [19] measure a corresponding 4 dB increase for a "U" space of different dimensions
from the "U" space analyzed in Appendix A of Reference 6.
There is some concern that the sound levels experienced in the upper stories of city
buildings might be unusually high if the observers are located above a compressor with pro-
nounced vertical directivity, particularly if the compressor sound is confined within a city
canyon. However, Appendix A of Reference 6 shows that an air compressor radiating sound
four times as efficiently (in terms of intensity) in the vertical direction than it does in the
horizontal direction would expose people in city buildings to less than 4 dB higher sound
levels than an air compressor that uniformly radiates an amount of sound energy. Thus, this
assertion does not appear to be valid.
A compressor operated under a bridge or overpass can be described in terms of the vault
space in Figure 7-9. The sound levels generated in such a space can be more than 10 dB
higher than the sound levels generated in a half space.
The barrier and pit configurations depicted in Figure 7-9 are typical of construction sites
in cities. Usually the construction of a building in a city center begins with the erection of a
tall broad fence. During the initial ground breaking, compressors operate at ground level
behind the fence. As excavation proceeds, compressors operate within the pit dug for the
basement floors. Calculations presented in Appendix B of Reference 24 show that pits and
barriers can reduce the noise levels experienced by outdoor ground level observers by as
much as 20 dB below the levels experienced in an unobstructed half space. The benefits to
upper story observers in buildings across the street depend on the construction stage, the
observer's elevation and on whether there are vertical reflecting surfaces in addition to those
shown in the barrier configurations in Figure 7-9.
7-30
-------
Section 8
AVAILABLE NOISE CONTROL TECHNOLOGY
UNITED STATES TECHNOLOGY
In 1968, a major manufacturer of portable air compressors demonstrated significant
noise reduction by the use of muffling devices and acoustic enclosures [25, 26]. Since
then, numerous manufacturers in the United States and abroad have applied various degrees
of noise control technology and have reduced portable air compressor noise. Figures 8-1
and 8-2 show two examples of effective noise control. In this section, the current state-of-
the-art of compressor noise control is discussed and noise control techniques are
summarized.
Most large air compressors are diesel-engine driven, screw-type compressors. The inter-
mediate sizes are diesel and gasoline-engine driven, screw- and rotary- type compressors,
while the smaller types are primarily gasoline-engine driven, screw-, rotary-, and recipro-
cating- type compressors. For all standard types, the major noise sources are the driving
engine and the fan associated with the engine and compressor cooling air system. A
description of the various types of compressors is contained in References 5 and 6.
Application of acoustic insulation, effective mufflers, shock mounts, damping material,
and some fan, cowling, and duct hardware modifications/improvements generally describe
the technology used to quiet compressors. Use of this technology has produced the mean
noise reductions listed in Table 8-1.
The values listed in Table 8-1 may be compared with the potential for noise reduction
discussed in Reference 3. As indicated in Reference 3, the potential noise reduction was
5 dB and 10 dB by the use of improved intake silencers and engine mufflers, respectively.
Note that the 5 dB and 10 dB noise reductions are not additive, because the total noise
reduction is dependent upon individually reducing the noise level of all the major sources
of noise. To determine more accurate potential noise reduction capabilities for com-
pressors, a study was conducted of the three quieted units:
1. A gas engine powered air compressor.
2. A diesel engine powered air compressor of less than 500 cfm capacity.
3. A diesel engine powered air compressor of greater than 500 cfm capacity.
8-1
-------
100
90
fj
r
I
1
:
60
;
.-
50
Unsilenced Unit
I
Silenced Unit
H 63 125 250 500 1000 2000 4000 8000
Octave Band Center Frequencies, Hz
NOTES: (1) CAGI/PNEUROP Position 10
(2) 900 cfm, 125psi
Figure 8-1. Noise Control Applied to the Ingersoll-Rand Model DXL 900
8-2
-------
100
90
80
0
70
5C
Unsilenced Unit
I
Silenced Unit
63
ffi DO
•0 T
125 250 500 1000 2000 4000 8000
Octave Band Center Frequencies, Hz
NOTES: (1) CAGI/PNEUROP Position 9
Figure 8-2. Noise Control Applied to the Atlas-Copco Model VT85 Dd
8-3
-------
Table 8-1
MEAN NOISE REDUCTION BETWEEN "STANDARD," "QUIETED,"
AND "QUIETEST" UNITS
Standard to
quieted units
Quieted to
quietest units
Gasoline
6.7 dB
3.8dB
Diesel
Below 500 cfm
9.7 dB
6.4 dB
Diesel
Above 500 cfm
H.ldB
5.2 dB
The purposes of the study were to determine the major sources contributing to com-
pressor noise, the effectiveness of the noise control techniques currently used by manufac-
turers, and the evaluation of additional noise control required to reduce each unit's noise
to 65 dBA, measured at 7 meters from the unit.
Gas Powered Engine Compressor
A Worthington 160 QT was selected for analysis. Significant noise sources of this
unit are the compressor, the engine and its cooling fan, the exhaust and muffler shells, and
the sai intake [7].
The engine and compressor assembly radiate noise directly, with the compressor
assembly somewhat attenuated by the surrounding air-oil tank. In addition, since they are
rigidly attached to the chassis and shell of the machine, both engine and compressor vibra-
tions are transmitted directly to the frame and outer sheetmetal, which also vibrate and
radiate noise.
The engine cooling fan can produce considerable broadband noise as the result of fan
design practices that would cause excessive turbulance of the air surrounding the fan. In
addition to generating noise, such practice would also reduce efficiency of both the fan and
the overall cooling system.
-------
The engine exhaust and muffler arrangement radiate noise via an airborne path
through the muffler exhaust gas-flow path and via the structure (shell) surrounding the
muffler. The air-intake system supplies air for the engine and compressor through a
common air filter and silencer. The two air-induction-pressures combine to form a
separate noise source.
The noise level at 7 meters to the right side of the "as sold" unit was 76 dBA. The
contribution of the principal noise sources to this level are tabulated in Table 8-2.
Table 8-2
WORTHINGTOIS COMPRESSOR 160 QT COMPONENT NOISE LEVELS
Ccitnponent
dBA
Engine and compressor casing
Engine cooling fan
Muffler shell
Exhaust.
Intake
74
69
66
62
61
The individual noise sources were carefully studied to determine the methodology to
further reduce the unit's noise level to the 65 dBA study level. Table 8-3 lists one com-
bination of noise control techniques and anticipated attendant noise reductions that, when
analytically combined with the compressor noise producing component source levels, may
result in a portable air compressor with a noise level of 65 dBA at 7 meters.
Diesel Powered Compressor, Less Than 500 cfm
The quieted Atlas Copco Super Silensair VSS170 Dd was selected for analysis [7].
This unit produces approximately 72 dBA at a distance of 7 meters from the unit. The
analysis of the units's noise signature indicates that the principal noise sources are the
engine casing, engine exhaust, engine air intake, compressor casing, and compressor cooling
fan, each of which produce the sound levels at 7 meters listed in Table 8^.
Midfrequency silencing is achieved by use of an enclosure having sidewalk and end
doors lined with a foam-type acoustic absorption material. The enclosure has built-in
8-5
-------
Table 8-3
PORTABLE AIR COMPRESSOR NOISE REDUCTION
Engine and
compressor
casing
Engine cooling
fan
Muffler shell
Exhaust
Intake
Noise Control Technique
•^^^
Vibration isolation plus increased
transmission loss through
side doors
Shroud redesign, blade twist
and reduced fan speed
Lagging with acoustic insulation
Additional muffling
Improved silencer
Noise Reduction
14 dB
11 dB
10 dB
5 dB
4 dB
Table 8-4
ATLAS COPCO COMPRESSOR (VSS170 Dd) COMPONENT NOISE LEVELS
Component
Engine casing
Engine exhaust
Engine intake
Compressor casing
Compressor cooling fan
dBA
63
60
61
64
63
8-6
-------
ducting for the engine and compressor air intake and cooling. Cooling air exhausted
from the diesel engine, the compressor and intercooler, is ducted through another part of
the enclosure prior to discharge. These ducts are primarily effective in blocking direct,
line-of-sight, internal noise radiation from the engine and compressor to the ambient. An
additional reduction of 5 to 7 dB in radiated sound could probably be obtained by employ-
ing the following noise reduction techniques:
• Application of damping material to the enclosure panels; damping will reduce
panel vibration levels and improve panel transmission loss due to the added mass.
• Increasing the internal sound absorption by (a) treating a larger amount of the
internal surface area and (b) using a thicker absorptive material.
NOTE: The absorptive material should be treated to prevent degradation due to
oil/fuel contamination.
• Use of a more effective vibration isolation mount to decouple the engine and com-
pressor from the chassis.
• Use of a more effective diesel exhaust muffler.
By using the preceding noise control techniques, a 7 dB overall reduction in a compressor
noise level of 65 dBA at 7 meters may result.
Diesel Engine Powered Air Compressor Greater Than 500 cfm Capacity
The "Blue Brute" 750-QTEX single stage, portable, rotary screw compressor manu-
factured by Worthington CEI was selected for study [7]. The 750-QTEX is a unit silenced
to produce 75 dBA at 7 meters. Among diesel powered compressors delivering greater than
500 cfm, the 750-QTEX is one of the quietest; it is only 1.5 dB noisier than the mean for
the lowest decile.
The technology by which the 750-QTEX has been quieted is also characteristic
of the quietest compressors in its category. It has rubber engine mounts, nonrigid hose
coupling, sealed doors, damped panels, interior sound absorption, silenced fan louvers
for cooling air intake and exhaust, two-stage custom designed muffler, bottom pan, and
a special cooling fan. Principal sources of the noise are listed in Table 8-5 along with
their individual noise levels.
3-7
-------
Table 8-5
WORTHINGTON COMPRESSOR 750 QTEX COMPONENT NOISE LEVELS
Component
Engine and compressor casing
Engine cooling fan
Muffler shell
Exhaust outlet
dBA
69
62,5
70
67
The 750-QTEX enclosure presently provides adequate noise reduction of engine
and compressor airborne sound, except at the cooling air intake and exhaust ducts.
Additional noise reduction is possible with design improvement of both the ducts and
the material used for acoustic absorption [7].
EUROPEAN TECHNOLOGY
Atlas Copco and CompAir compressors use a double-wall enclosure that serves as an air
duct and silencer as well as a barrier to engine and compressor radiated noise. All the "Super
Silenced" Atlas Copco air compressors are of the reciprocating type. Discussions with Atlas
Copco indicate that reciprocating air compressors are more efficient, with less heat rejection.
Atlas Copco uses air cooled engines with cooling fans built in, which demonstrate a much
better performance than the fans measured on domestic air compressors. CompAir com-
pressors use a sliding vane or rotary screw type compressor with a water cooled Perkins diesel
engine. The pusher type fan is well shrouded. Proper air flow through either unit requires
door-shut type operation. The noise control technology used in Europe is similar to that
used in the United States, but a more systematic approach is applied to quieting air compressors.
Noise control design is more from the frame up and uses an integrated approach rather than
merely adding on quieting components. Foreign "super silenced" air compressors tend to
have a boxy look.
To achieve low noise levels, enclosures should be absolutely sealed under operation
in order to avoid noise leaking out through even small openings. It has been reported that
large compressors emitting less than 65 dBA under full power are already on the market[27].
8-8
-------
Section 9
ECONOMIC STUDY
Section 6 of the Noise Control Act of 1972 provides that the Administrator of the
Environmental Protection Agency (EPA) shall establish noise emission standards (when
feasible) for products that are found to be major sources of noise and which fall into specific
product categories. Construction equipment is one such category and the portable air
compressor is a piece of equipment in that category.
Section 6 further states that the regulation:
shall include a noise emission standard which shall set limits on noise
emissions from such product and shall be a standard which ... is
requisite to protect the public health and welfare, taking into account
the magnitude and conditions of use of such product . . . the degree
of noise reduction achievable through the application of the best
available technology, and the cost of compliance . . . Any such noise
emission standards shall be a performance standard. In addition,
any regulation . . . may contain testing procedures necessary to assure
compliance with the emission standard in such regulation, and may
contain provisions respecting instructions of the manufacturer for
the maintenance, use, or repair of the product.
To address the potential economic impact of noise emission regulations upon the
various affected societal units (industry, user, suppliers), EPA acquired data on the pricing
characteristics, dollar sales, and unit sales of the portable air compressor manufacturing
industry. Additional information was developed on the costs of quieting portable air com-
pressors using the current production technology and on the best available quieting tech-
nology. The major conclusions of the economic impact analysis performed with these data are
presented in this section.
The objective of the analysis was to assess the economic impact of the adoption of
alternate noise emission standards for the portable air compressor industry. This assessment
included consideration of the impact on raw material and component suppliers, distributors,
manufacturers, and users, and the general public. The impact on key governmental policy
concerns such as employment and the balance of trade was also assessed.
9-1
-------
INDUSTRY BACKGROUND
Dollar Sales
Sales of portable air compressors are sensitive to government and private construction
activity. Sales of large units have historically followed trends in the construction industry,
while smaller units have followed the general economy. Dollar value of portable air com-
pressor shipments has fluctuated between $58.7 million and $89.7 million during the years
1967 through 1972.
Table 9-1 presents the value of total portable air compressor shipments during 1967
through 1972. The data of Table 9-2 were derived from information made available by the
Compressed Air and Gas Institute and the Department of Commerce. The derivation of
these data is discussed in Reference 8.
Table 9-1
ESTIMATED DOLLAR VALUE OF ANNUAL SHIPMENTS OF
PORTABLE AIR COMPRESSORS: 1967-1972
Year
1967
1968
1969
1970
1971
1972
Value of Shipments
(millions)
$58.7
59.9
75.3
70.3
74.1
89.7
Portable Air Compressor Prices
The Bureau of Labor Statistics maintains wholesale price indices on two capacity
classes of portable air compressors, 100 to 300 cfm and 600 cfm. The price indices for
both classes fell between February 1968 and February 1972 (13 and 11 percent, respectively)
By May 1975, prices for both classes had risen substantially, 22 percent for the smaller com-
pressors and 35 percent for the larger ones. Table 9-2 presents average list prices of portable
9-2
-------
Table 9-2
ESTIMATES OF PORTABLE AIR COMPRESSOR
AVERAGE 1975 LIST PRICES
Capacity (in cfm) and
Power Source Type
75 - 124 Gas
124 - 250 Gas
124 - 250 Diesel
251 - 750 Diesel
600 - 899 Diesel
900 and over Diesel
Estimated Average List
Price
$ 5,667
7,867
9,614
35,661
60,493
87,388
air compressors by power source and rated air flow capacity computed from data collected
by EPA in the spring of 1975.*
Percent Distribution by Type Compressor
The portable air compressors currently manufactured are primarily powered by gasoline
or diesel engines. Three basic types of compressors are used in portable air compressors:
rotary screw, sliding vane, and reciprocating. Table 9-3 illustrates the distribution of engine
and compressor type according to engine capacity.
Unit Sales
Data on total unit shipments tabulated in Table 9-4 presents another picture of the por-
table air compressor market. From 1967 through 1972, portable air compressors experienced
moderate by cyclical growth, averaging approximately 3 percent annually. Sales surged dramati-
cally from 1972 to 1973, increasing by approximately one third. Although recent sales data are
not available, it is understood that the surge continued into 1974.
*A11 portable air compressor pricing is based on discounts from published list prices. The
manufacturers published discount schedule typically ranges from 20 to 25 percent. How-
ever, discounts to distributors can vary from 15 to 45 percent, depending on volume and
other transaction factors.
9-3
-------
Table 9-3
DISTRIBUTION OF ENGINE TYPES AND COMPRESSOR DESIGN TYPES
ACCORDING TO RATED ENGINE CAPACITY IN CFM AT 100 PSIG
Compressor Type
Reciprocating
Vane
Screw
All types
75-200 cfm
Gasoline
16.6%
25.6%
15.4%
57.6%
Diesel
10.3%
19.2%
12.8%
42.3%
Gasoline
and
Diesel
26.9%
44. 8%
29.2%
99.9%
201-500 cfm
Gasoline
0%
10.3%
2.6%
12.9%
Diesel
30.8%
33. 3%
23. 1%
87. 2%
Gasoline
and
Diesel
30.8%
43.6%
25.7%
100. 1%
Above 500 cfm
Gasoline
0%
0%
0%
0%
Diesel
6.8%
17.0%
76.3%
100. 1%
Gasoline
and
Diesel
6.8%
17.0%
76. 3%
100. 1%
Table 9-4
UNIT SALES OF PORTABLE AIR COMPRESSORS,
1967 - 1973
Year
1967
1968
1969
1970
1971
1972
Rated Air Flow Capacity
Below 251
8,313
8,156
9,586
9,233
8,138
10,183
1973 | 13,286
Above 250
1,656
1,563
1,691
1,740
1,763
1,971
2,697
Trvtol
1 Oldl
9,969
9,719
11,277
10,973
9,901
12, 154
15,983
9-4
-------
Table 9-5 presents 1972 portable air compressor sales by power source type and
capacity.
Table 9-5
PORTABLE AIR COMPRESSOR 1972 SALES BY POWER SOURCE
TYPE AND CAPACITY CATEGORY
Power Source Type
and Capacity cfm
75 - 124 gasoline
125 - 250 gasoline
125 - 249 diesel
250 - 599 diesel
600 - 899 diesel
900 and over diesel
Total
Unit Shipments
3,082
4,827
2,101
576
1,095
473
12,154
Total
25.4
39.7
17.3
4.7
9.0
3.9
100.0
Price Per CFM
In its initial assessment of the portable air compressor market EPA divided compressors
into six categories based on engine type, rated air flow capacity, and whether or not they
were standard or quieted units. This division was made to get a definitive picture of price
and sound level differentials.
Table 9-6 presents a summary of the state of noise emissions and price of portable air
compressors in 1973, showing, for each category, the mean price per cfm and sound levels
at 7 meters (measured according to ISO 2151-1972).
The price differential between standard and quieted compressors is greatest for the
larger (i.e., above 250 cfm) compressors. The sound levels of both standard and quieted
versions of the large compressors are presented in the table.
9-5
-------
Table 9-6
NOISE EMISSIONS AND 1973 PRICE PER RATED cfm OF STANDARD AND QUIETED
VERSIONS OF PORTABLE AIR COMPRESSORS OF THE SAME MODEL
Number of Units
Mean Price Per cfm
Mean SPL at 7m (dBA)
Price Increase,
Standard to Quiet:
Amount
Percent
aasoune^
Standard
23
$38.83
84.1
Quieted
23
$42. 51
76.5
$3.76
9.5
Diesel Driven
Below 251 cfm
Standard
21
$45.91
84.3
Quieted
22*
$49.51
76.6
$3.60
7.8
Above 250 cfm
Standard
24
$44. 20
92.2
Quieted
24
$49. 53
78.3
$5.33
12.1
*Includes one model that had two quieted versions.
-------
REGULATORY OPTIONS INVESTIGATED
In an initial analysis, noise levels associated with three broad categories of portable air
compressor capacities were evaluated to assess the attendant impacts associated with the
application of quieting technology. The levels selected for study were based on noise
emission data of 194 portable air compressors, which represented about 55 to 65 percent
of the models offered for sale. The levels selected for study are listed in Table 9-7 along
with underlying rationale for their selection.
Table 9-7
INITIAL SOUND LEVEL LIMITS SELECTED FOR STUDY
Level One
Level Two
Level Three
Gasoline Driven
All cfm
Ratings
76 dBA
73 dBA
65 dBA
Diesel Driven
Below 501
cfm
76 dBA
70 dBA
65 dBA
Diesel Driven
Above 500
cfm
76 dBA
73 dBA
65 dBA
Note: Levels constitute a "not to exceed" criteria.
Subsequent analysis considered the cost and economic impacts of several regulatory
options, the primary dimensions of which were the maximum allowable sound pressure level
(76 dBA or 78 dBA) and the time allowed for compliance. These opt.uns are listed in Table
9-8 and include lead times to compliance ranging from 12 to 30 months. Available data are
not sufficient to allow an analysis of the sensitivity of the direct cost of compliance to
variation in the lead time (e.g.. the addition to costs of achieving compliance in 18 months
instead of 30 months).
Consideration of the adjustments required for manufacturers to achieve compliance and
estimates provided by BBN [7] suggest a lower bound on the time required for orderly adjust-
ment of 12 to 15 months and an upper bound of 24 to 30 months. The manufacturer adjust-
ments referred to include the acquisition of such new components as quieter engines, better
mufflers, and new acoustical enclosures in addition to the design modifications required to
incorporate these new components into the air compressors.
9-7
-------
Table 9-8
REGULATORY OPTIONS
Regulatory
Option
1
2
3
4
5
6
7
8
9
10
11
12
Air Flow
Capacity
(cfm)
All
All
All
Under 251
Above 250
Under 251
Above 250
Under 251
Above 250
Under 251
Above 250
Under 251
Above 250
All
All
Under 251
Above 250
Under 251
Above 250
Sound Pressure
Level
(dBA at
7 meters)
76
76
78
76
76
76
76
76
78
76
76
76
78
76
78
76
76
78
Time to
Compliance
(months)
12
18
18
18
24
12
24
12
18
12
18
18
24
24
24
24
30
24
30
9-8
-------
In the spring of 1975, EPA conducted a survey of the portable air compressor industry
to obtain estimates of the time required to achieve compliance with the 76 dBA and 78 dBA
standards. The resulting data, presented in Table 9-9, shows the percent noise impact reduc-
tion, the average percent list price increase, the annual aggregate increase in purchase cost,
and the first year annualized user costs that would accrue as a result of each regulatory option.
The table also presents the percentage of units in each major capacity class, that would
be brought into compliance in the time frame specified for each regulatory option. The
major finding of the industry survey was that a significant number (59 percent) of portable
air compressors could not be made to comply with a 76-dBA standard in the 12 months
(option 1) specified in the proposed rulemaking for portable air compressors (FederalRegister,
October 29, 1974). The additional analysis performed was limited to regulatory options
allowing, at a minimum, 18 months' lead time for compliance.
IMPACTS ON LIST PRICES OF ALTERNATIVE NOISE EMISSION STANDARDS
Two procedures were used to evaluate the impact of possible increases in list prices
resulting from the adoption of noise emission standards. For the first procedure, data
presented in Table 9-6 were used to estimate the percent increase in prices resulting from
quieting standard portable air compressors to the average sound level of quieted
(76 or 77 dBA for most engine/capacity classes). The second procedure (based on a
regression analysis of the data listed in Table 9-6) was used to estimate the price effects
of additional quieting down to a sound pressure level of 73 dBA.* Each evaluation is
based on an analysis of matched pairs, i.e., pairs of portable air compressor models in
which the first model of each pair is a standard unquieted version and the second model
is a quieted version.**
The estimates of price impacts given in this report should be interpreted as applying to
a lead time that allows orderly adjustments, corresponding to the conditions presumably
reflected in the list price/sound level data used for the estimates. The term orderly adjust-
ment, as used here, implies that sufficient lead time to compliance has been allowed so that
there are no serious adverse impacts on manufacturers, suppliers, or users that could be
avoided by a reasonable extension of the time to compliance. In other words, there would
be no plant shutdowns, serious supplier or user disruptions, or precipitous changes in market
*73 dBA corresponds to a 76 dBA emission standard and a 3 dBA production tolerance.
**See Reference 33 for a more complete description of the methodology.
9-9
-------
Table 9-9
IMPACT OF PORTABLE AIR COMPRESSOR NOISE EMISSION REGULATION
Option
1
2
3
4
5
6
7
8
9
10
11
12
cftn
All
All
All
<250
>250
<250
>250
<250
>250
<250
>'250
<250
>250
All
AU
<250
>250
<250
>250
SPL
dBA
76
76
78
76
76
76
76
76
78
76
76
76
78
76
78
76
76
78
Time
Months
12
18
18
18
24
12
24
12
18
12
18
18
24
24
24
24
30
24
30
Health &
Welfare
Noise
Impact
Reduction1
(%)
14.7
14.7
14.0
14.7
14.7
14.6
14.7
14.6
14.7
14.0
14.7
14.6
Cost of Compliance
Average
List Price
Increase
%
(16)2
12.3
10.0
12.3
12.3
11.2
12.3
11.2
12.3
10.0
12.3
11.2
Annual
Aggregate
Increase In
Purchase Cost-*
$ Million
(22)2
25.0
20.3
25.4
25.4
23.4
25.4
23.4
25.0
20.3
25.4
23.4
1st Year
User
Annualizec1
Costs*
$ Millions
(3.8)2
5.0
4.1
5.1
5.1
4.7
5.1
4.7
5.0
4.1
5.1
4.7
Potential
Percent of
Compressors Not
Ready for Sale
<250 cfm
54
21
1
21
54
54
54
21
0
0
0
0
>250 cfm
80
57
47
16
16
47
57
10
16
10
0
0
1 Baseline is 27.4 million people exposed to construction site noise with levels above 55 L^.
2 These numbers were derived on the premise that manufacturers could accomplish the redesign of their
entire product line in 12 months. According to new data and information acquired, this assumption and
resulting estimates based on it are in error.
3 Based on estimated $206 million in sales in 1977-1978.
4 Based on estimated 10% depreciation and an estimated 10
-------
shares that result from a severe increase in adjustment costs to a manufacturer and that could
be substantially reduced if the manufacturer had additional lead time to bring his product
line into compliance.
Estimates were made assuming not-to-exceed sound level standards of 78 and 76 dBA
(at 7 meters) and production tolerances of both 2 and 3 dBA. These standards and production
tolerances result in four production sound level targets:
1. 76 dBA = 78 dBA standard with a 2 dBA tolerance
2. 75 dBA = 78 dBA standard with a 3 dBA tolerance
3. 74 dBA = 76 dBA standard with a 2 dBA tolerance
4. 73 dBA = 76 dBA standard with a 3 dBA tolerance
The resulting estimated percent increases in list price associated with the sound level targets
are listed in Table 9-10.
Table 9-10
ESTIMATED PORTABLE AIR COMPRESSOR LIST PRICE INCREASES
BY MAJOR ENGINE/CAPACITY CLASS AND ALL MODELS
SPL
Target
76 dBA*
75 dBA**
74 dBA*
73 dBA**
Percent Increase in Price
Gasoline
8.5%
10.3
12.1
14.2
Diesel
Below
251 cfm
7.0%
8.2
9.6
10.9
Diesel
Above
250 cfm
11.4%
12.1
13.0
13.9
All
Models
10. 0%
11.1
12.3
13.6
*2 dBA tolerance
**3 dBA tolerance
9-11
-------
For compressors with rated capacity above 250 cfm, the estimates given in Table 9-10
used data that excluded 600 cfm compressors. The reason for this exclusion is that com-
pressors with 600 cfm and 750 cfm rated air flow appear to be relatively close performance
substitutes for each other, and the data suggest substantially more quieting experience and
lower incremental costs of quieting for the 750 cfm machines. Should the cost differential
persist, one may anticipate a substantial shift of market shares away from 600 cfm com-
pressors in favor of the 750 cfm machines. The estimates are made under the assumption
that 600 cfm machines either adopt the cost-of-quieting characteristics of or are replaced
in the market by the 750 cfm machines.
An additional set of estimates was computed to test the sensitivity of the results to the
use of less optimistic assumptions; that is, the 600 cfm compressors retain their share of the
market and remain relatively expensive to quiet. Table 9-11 lists the estimated list price
increases resulting from the less optimistic assumption. For comparative purposes, list
price increases associated with the more optimistic approach are also listed in the table.
Table 9-11
COMPARISON OF ESTIMATED PORTABLE AIR COMPRESSOR
LIST PRICE INCREASES DERIVED UNDER TWO ASSUMPTIONS
SPL Target
dBA
73
75
Percent List Price Increase for Compressors
Above 250 cfm
Assumption 1*
13.9
12.1
Assumption 2**
19.4
16.4
*600 cfm compressors replaced by 750 cfm units.
**600 cfm compressors retain their market share.
As was mentioned earlier, there are significant differences between the list prices and
actual transaction prices of portable air compressors. Discounts from list prices of up to 45
percent are reportedly common. Ideally, the estimates should be based on actual transaction
prices. Also, the sound level and price data are 2 years old. Portable air compressor prices
have increased substantially during this period, and it is likely that the price behavior of
quieted and standard models have not always coincided. Additionally, the industry has 2
years of quieting experience not reflected in the data.
9-12
-------
It is not now possible to assess the effect that improved data would have on these
estimates; however, there is no reason to believe that better data would show a significant
increase in the estimated price impacts given.
ECONOMIC IMPACTS OF ALTERNATIVE REGULATORY OPTIONS
The economic impact analysis that follows is built upon the price in the preceding
impact analysis. The economic impact analysis study was separated into six segments:
1. Price and Sales Impacts. This segment includes the analysis of price impacts and
results and changes in industry sales that occur relative to a baseline forecast.
2. Cost of Compliance. This segment includes the cost of the resources used to
achieve compliance with the regulatory options and reflects the increased costs of
producing quieted equipment and the cost associated with changes in performance
and maintenance.
3. Market Impacts. This segment includes an analysis of broad changes in industry and
market conditions that might accompany the adoption of alternative noise emission
standards.
4. Foreign Trade. This segment covers an assessment of the impacts on exports, imports,
and balance of trade.
5. Individual Impacts. This segment gives an assessment of market impacts that fall
differentially on specific companies or industry segments, such as unemployment,
lowered sales and profits, or changes in market shares.
6. Disruptive Impacts. This segment considers changes that may occur in response to
various shutdowns, unemployment, etc., that may be caused by the regulation of
portable air compressors.
Two approaches were used to assess economic impact: (1) making direct estimates
based on field interviews and (2) using published information and making indirect estimates
by projecting market conditions with and without noise emission standards.
The data on which to base the estimated impacts were obtained from several sources
including manufacturers of portable air compressors.
9-13
-------
The assumed portable air compressor industry/market reactions to noise regulations
are:
1. The total costs to manufacture the equipment will increase.
2. The manufacturers will pass this cost on in the form of an increase in the distributor
price (list price).
3. The distributor will pass its cost increase on in the form of an increase in the nego-
tiated customer price.
4. The portable air compressor end user will pass the increase in his equipment purchase
costs on to his customers as an increase in the price of products and services provided.
5. Final changes in industry prices and volumes will reflect the changes in portable air
compressor purchase prices and operating costs.
6. Ultimately, the consumer will pay a higher price for products due to the required
increased cost to reduce noise.
If there are overall cost reductions, as opposed to cost increases, from the adoption of
noise control technology, competitive pressures will cause cost decreases to be passed on up
the economic chain to the consumer in the form of lower prices.
The scenario under which the economic impacts were estimated is based on the tech-
nology and costs contained in References 5, 7, and 33. The estimates of impacts given here
assume that the conditions reflected in the 1973 sound level/price data represent the actual
technology adopted and costs to be incurred in the future. It is likely that new technologies
at lower costs will be developed. Thus, if the current costs, based on an assessment of on-
the-shelf technology, are reasonably accurate, they give upper bound estimates. Noise
standards can be attained at these costs, but possibly they will be attained at less cost based
on better future technology.
Price and Sales Impacts
It is assumed that purchasers of portable air compressors will be presented with a price
increase associated with each noise emission standard selected for study. Estimated price
increases attributable to compliance with various regulatory options were presented in
Table 9-10. The list price was selected as the basis for the economic impact analysis because
it is conservatively constructed and is based on the broadest sample of cost and noise sup-
pression data available.
9-14
-------
Table 9-12 presents estimates of average list price percentage increases and resulting
decreases in sales associated with manufacturer compliance with the regulatory options,
assuming a price elasticity of demand of -0.35.
Rising prices can be expected to result in reduced sales as demand falls off because
users will either find more efficient ways to use gasoline or diesel-engine driven air com-
pressors, in an effort to cut costs, or will switch to substitute products that provide a lower
cost alternative method of performing the same work. The degree to which sales will fall
depends on the ease with which buyers can change their compressor use habits in different
applications in order to cut costs.
With price increases below 20 percent (constant dollars) air compressor users will
probably refrain from widespread immediate substitution because:
1. Portable air compressors are a convenient power source for many applications.
2. Users currently have a high investment in tools that operate on compressed air
(costing 10 to 200 percent as much as the compressor).
3. Costs of using compressors can be lowered somewhat without substitution through
more renting of equipment and other practices.
Demand may fall off more rapidly in response to price increases in excess of 20 percent as it
becomes worthwhile to substitute hydraulic or electric systems for compressed air systems.*
Decreased industry sales for all options range between 3 and 5 percent. The largest sales
impact generally falls on the diesel-driven compressors with more than 250 cfm capacity. These
impacts are equivalent to 1 or 2 years of sales growth at the rates experienced by the industry
from 1967 to 1972, but are less than one-fifth of the industry sales growth from 1972 to
1973. (Sales data for 1974 are not available.)
*The response to price increases in this discussion is considered under the assumption that
the prices of substitutes remain constant. To the extent that substitutes for portable air
compressors experience comparable price increases, e.g., due to other government regula-
tions, the demand response to increasing air compressor prices will be dampened.
9-15
-------
Table 9-12
ESTIMATES OF INCREASED PRICES AND DECREASED SALES
ASSOCIATED WITH THE REGULATORY OPTIONS
Regulatory
Option
2
3
4
8
9
10
11
12
Air Flow
Capacity
(cfm)
All
All
Under 251
Above 250
Under 251
Above 250
All
All
Under 251
Above 250
Under 251
Above 250
Sound
Pressure
Level
(dBA at
7 meters)
76
78
76
76
76
78
76
78
76
76
78
Time to
Compliance
(months)
18
18
18
24
18
24
24
24
24
30
24
30
Percent Price
Increase
2 dBA
Tolerance
12.3
10.0
12.3
11.2
12.3
10.0
12.3
11.2
3 dBA
Tolerance
13.6
11.1
13.6
12.5
13.6
11.1
13.6
12.5
Percent Decrease
In Sales
(elasticity of -0. 35)
2 dBA
Tolerance
4.3
3.5
4.3
4.0
4.3
3.5
4.3
4.0
3 dBA
Tolerance
4.8
3.9
4.8
4.3
4.8
3.9
4.8
4.3
MD
-------
Impact on Industry Employment
Decreased industry sales will tend to lower employment in the industry. However, the
labor required per manufactured compressor will tend to increase, due to the quieting require-
ments. Data are not available to determine the net effect of these two counteracting forces.
A portion of any net decrease in employment could be accomplished by normal attri-
tion. It has been common in recent years for between 2 and 3 percent of the labor force in
all manufacturing to leave their job voluntarily. Data on labor turnover in the portable air
compressor industry are not available.
Based on the estimated impacts on industry sales, industrywide employment impacts of
any of the regulatory options would not appear severe, provided sufficient compliance time
is allowed.
COST OF COMPLIANCE
The total cost of achieving compliance with any of the regulatory options is composed
of many parts. Additional resources - labor, materials, and capital - must be used in the
production of the quieter compressors.* To the extent that the users of portable air com-
pressors go to substitute technologies (e.g., electric and hydraulic equipment) or make
other adjustments to avoid purchasing the higher priced compressors, they may adopt
alternative methods of production that presumably would have been more costly than the
lower priced unquieted compressors. Users are therefore avoiding the cost of higher priced
compressors by incurring the cost of previously less favored methods of production. And
to the extent that new air compressor sales are reduced, labor in the industry may be unem-
ployed while moving their present employment to alternatives - a third type of resource
cost.
Data are not available to assess the value of each of these components of the costs of
complying with the regulatory options and the distribution of these costs among differ-
ent segments of society (e.g., labor, the construction industry, the purchasers of new con-
struction, and the compressor manufacturing industry). As an alternative, an assessment has
been made under the assumption that the only societal adjustment to the new regulations is
to reallocate the required resources to the air compressor industry to produce quieter equip-
ment. This assumption implies that there is no decrease in industry sales in response to
higher prices and, consequently, no associated unemployment. The assumption is also made
*Increased user operating and maintenance costs are assumed to be negligible. See Reference 8.
9-17
-------
that the increase in list price includes a normal profit or return on capital resources utilized
in the quieting of compressors.
With these assumptions, the total cost of compliance with a regulatory option may be
approximated by the dollar value increase in compressor sales under the assumption that
prices increase by the percentages given in Table 9-10 and that unit sales are not changed in
response to the higher prices. This assessment makes no statement as to the manner in
which these costs are distributed among the different segments of society.
Using these assumptions, an annual aggregate increase in purchase cost was calculated
for the first year of full compliance for each regulatory option. The base year sales used in
the calculation is for the 12 months beginning on the date all new compressors (regardless
of capacity) are covered by the regulation, assuming the regulation is promulgated in July
1975. EPA has estimated that total portable air compressor retail sales in 1977-1978
will be approximately $206 million.
The results of the calculations are presented in Table 9-13, where it is shown that the
annual aggregate increase in purchase cost relating to the regulatory options range from $20
to $28 million.
User Costs
If a user purchases a new quieter and more expensive portable air compressor, the higher
price paid represents an increase in his investment expenditures. The book value of his equip-
ment (carried at cost) will be increased by the amount of the higher price. This amount will
be depreciated over the accounting life* of the equipment in order to allocate the cost of
equipment over the revenue received through its operation.
If the user borrows the funds required to finance the purchase, he bears an additional
interest cost attributable to the higher purchase price of the equipment. If he uses equity
financing, he foregoes the opportunity of investing the additional funds in other income
generating activities and thus incurs an opportunity cost just as real as the interest cost of
debt financing. In either case, the user bears an increased cost of financing the equipment
purchase that may be associated with the higher price.
It is assumed depreciation is 10 percent of the original cost of the equipment and that
10 percent of the purchase price gives an appropriate cost of the increased purchase price to
*Accounting life and true, useful life need not coincide.
9-18
-------
Table 9-13
ESTIMATES OF THE ANNUAL AGGREGATE INCREASE IN PURCHASE COST
RELATED TO ALTERNATIVE REGULATORY OPTIONS
Regulatory
Option
2
3
4
8
9
10
11
12
Air Flow
Capacity
(cfm)
All
All
Under 251
Above 250
Under 251
Above 250
All
All
Under 251
Above 250
Under 251
Above 250
Sound
Pressure
Level
(dBA at
7 meters)
76
78
76
76
76
78
76
78
76
76
78
Time to
Compliance
(months )
18
18
18
24
18
24
24
24
24
30
24
30
Annual Aggregate Increase
In Purchase Cost
($ millions)
2 dBA
Tolerance
25.0
20.3
25.4
23.4
25.0
20.3
25.4
23.4
3 dBA
Tolerance
27.6
22.6
27.9
25.7
27.6
22.6
27.9
25.7
-------
his operating costs each year. It is also assumed that all other costs incurred by the user as a
result of the noise regulations are negligible.*
For the first full year of compliance, the increased cost to appear in the income state-
ments of the users of the new quieted equipment is, with the assumptions given above, equal
to 20 percent of the annual aggregate increase in purchase cost given in Table 9-13. These
first year user annualized costs are presented in Table 9-14 and range between $4 and $6
million.**
To calculate the corresponding user annualized cost for the first year of a 100-percent
quieted portable air compressor population, the following assumptions were made:
• All new quieted equipment survives at least 10 years.
• No existing unquieted equipment survives more than 10 years.
• Portable air compressor sales grow at a constant rate over the first 10 years of the
regulation.
Two sets of growth rates are used. The first set is the average annual rate of unit sales
growth experienced from 1967 through 1972 (i.e., 2.8 percent for small compressors and
3.6 percent for large compressors) and the second rate of growth is that experienced from
1967 through 1973 (i.e., 6.0 percent for small compressors and 7.0 percent for large com-
pressors).***
These growth rates result in 100-percent quieted populations at the end of 10 years equal
to 11.61 and 13.56 times the number of new compressors purchased during the first full year
of compliance. These 100-percent quieted user annualized costs are presented in Table 9-15,
with the values ranging between $48 and $76 million.
These values are small relative to the total value of construction, corresponding to the
relatively small portable air compressor industry. The 100-percent quieted user annualized
cost of $76 million, for example, is only 0.06 percent of the $135 billion value of new con-
struction in 1973.
*See Reference 8.
**These costs may be considered a component of the annual aggregate increase in purchase
cost and should not be added to the values given in Table 9-13.
***It is not anticipated that the higher (i.e., 6 and 7 percent) growth rates will be maintained.
The use of these growth rates therefore yields an upper bound on the difference between
first-year and 100-percent quieted estimates.
9-20
-------
Table 9-14
FIRST YEAR USER ANNUALIZED COSTS OF ALTERNATIVE REGULATORY OPTIONS
to
Regulatory
Option
2
3
4
8
9
10
11
12
Air Flow
Capacity
(cfm)
All
All
Under 251
Above 250
Under 251
Above 250
All
Ail-
Under 251
Above 250
Under 251
Above 250
Sound
Pressure
Level
(dBA at
7 meters)
76
78
76
76
76
78
76
78
76
76
78
Time to
Compliance
(months)
18
18
18
24
18
24
24
24
24
30
24
30
First Year User
Annualized Costs
($ millions)
2 dBA
Tolerance
5.0
4.1
5.1
4.7
5.0
4.1
5.1
4.7
3 dBA
Tolerance
5.5
4.5
5.6
5.1
5.5
4.5
5.5
5.1
-------
Table 9-15
100 PERCENT QUIETED POPULATION USER ANNUALIZED COSTS
OF ALTERNATIVE REGULATORY OPTIONS
Regulatory
Option
2
3
4
8
9
10
11
12
Air Flow
Capacity
(cfm)
All
All
Under 251
Above 250
Under 251
Above 250
All
All
Under 251
Above 250
Under 251
Above 250
Sound
Pressure
Level
(dBA at
7 meters)
76
78
76
76
78
76
78
76
76
78
Time to
Compliance
(months)
18
18
18
24
18
24
24
24
24
30
24
30
User Annualized Cost, 100% Population ($ million)
1967-1972
Growth Rate*
2 dBA
Tolerance
58.1
47.6
59.0
54.6
58.1
47.6
58.1
54.6
3 dBA
Tolerance
63.9
52.2
65.0
59.2
63.9
52.2
63.9
59.2
1967-1973
Growth Rate**
2 dBA
Tolerance
67.8
55.6
68.9
63.7
67.8
55.6
67.8
63.7
3 dBA
Tolerance
74.6
61.0
75.9
69.2
74.6
61.0
74.6
69.2
*2. 8 percent for small compressors and 3.
**6.0 percent for small compressors and 7.
6 percent for large.
0 percent for large.
-------
This implies that any regulation that does not cause significant disruptions in the supply
of portable air compressors will probably have relatively little aggregate impact outside the
portable air compressor industry.
Market Impact
The impact of promulgating noise emission levels for portable air compressors on the
market and industry as a whole is discussed in greater detail in Reference 8. However, this
discussion treats in a summary form those impacts on the market that can be expected from
the adoption of noise control technology. Included in this summary are the impacts on
upstream components suppliers, downstream distributors, and end users.
Suppliers
The suppliers of components to (1) engine manufacturers, (2) muffler manufacturers,
(3) fan manufacturers, and (4) enclosure and vibration isolator manufacturers will generally
experience higher dollar sales. General suppliers to portable air compressor manufacturers
will not be adversely affected by the adoption of noise control technology primarily because
most suppliers to the industry derive only a small portion of their business from manufac-
turers of portable air compressors.
Distribution
Channels of distribution and portable air compressor operations are not expected to
materially change due to the noise emission standards.
End Users
It has been estimated that the increased costs to be incurred by portable air compressor
owners will be less than 0.1 percent of total operating costs of end user industries. Therefore,
little, if any, change in portable air compressor end user industries are expected.
9-23
-------
Foreign Trade
This discussion addresses the impact of the adoption of noise standards on export and
import patterns for portable air compressors. Noise regulations do not apply to export
products but do apply to products imported for use in the United States.
Exports
Domestic portable air compressor manufacturers will be able to export both quieted
and unquieted products to foreign countries, depending upon their respective noise regula-
tions To the extent that some foreign markets presently require quiet compressors
domestic manufacturers wiU-be in an improved competitive position. Stud, ^puts ^om
portable air compressor manufacturers indicated that no changes in export patterns are
expected.
Imports
Imports currently account for between 5 and 10 percent of the total domestic portable
air compressor unit consumption. Imported portable air compressor pnces «J"«^
competitive with or lower than domestic manufacturer pnces. However, imports have not
Sficanay penetrated the United States market because of lack of effective d,s,nbu,,on
networks pVor product quality in some instances, poor service and parts dehvery, and
ntnsheTmpetition by domestic producers. Quieted imported portable air compressors
"no, expected to make significant taroads into the *^^™£«£ "~
dated with quieting, plus import costs would exceed the costs incurred by domesfc
producers.
Balance of Trade
Based on the factors reviewed, no material impact on the balance of trade is anticipated.
Individual Impacts
This discussion addresses differential impacts that may develop affecting a single firm or
set of firms.
9-24
-------
Small Portable Air Compressor Manufacturers
Small manufacturers may not have sufficient manpower and/or funds to immediately
allocate to the required development programs. However, costs and^ quieting technology
are not expected to create a problem for small manufacturers provided they are given
adequate time to adjust.
Firms Experienced in Noise Technology
Those firms having already attained experience in quieting technology and currently
having quieted products on the market are much better prepared to meet Federal noise
emission levels. Thus, they are expected to hold an advantage in the market for a limited
period of time.
Disruptive Impacts
Given adequate lead time and appropriate planning, no significant disruptive economic
impacts are predicted due to the establishment of noise standards per se.
Cost changes are on the order of 10 to 13 percent. However, volume changes are small
relative to baseline conditions. The portable air compressor industry would be expected to
continue its normal growth pattern. Some small unemployment (measured in tens) may
occur in specific communities.
9-25
-------
SUMMARY
1. Compressor list prices may increase as shown in Table 9-16.
Table 9-16
SUMMARY OF ESTIMATED PRICE INCREASES
(in percent, with 2 dBA tolerances)
Engine/Capacity Class
Gasoline (All)
Diesel (<250 cfm)
Diesel (>250 cfm)
Average
Option
2
12.1
9.6
13.0
12.3
Option
3
8.5
7.0
11.4
10.0
Option
4
12.1
9.6
13.0
12.3
Option
8
12.1
9.6
11.4
11.2
Option
9
12.1
9.6
13.0
12.3
Option
10
8.5
7.0
11.4
10.0
Option
11
12.1
9.6
13.0
12.3
Option
12
12.1
9.6
11.4
11.2
The price increases will be passed on to end users.
2. Sales may be affected as indicated in Table 9-17
Table 9-17
SUMMARY OF ESTIMATED SALES REDUCTIONS
(in percent, with 2 dBA tolerances)
Engine/Capacity Class
Gasoline (All)
Diesel ( < 250 cfm)
Diesel ( >250 cfm)
Average
Option
2
4.2
3.4
4.6
4.3
Option
3
3.0
2.4
3.5
3.5
Option
4
4.2
3.4
4.3
4.3
Option
8
4.2
3.4
4.0
4.0
Option
9
4.2
3.4
4.6
4.3
Option
10
3.0
4.0
3.5
3.5
Option
11
4.2
3.4
4.6
4.3
Option
12
4.2
3.4
4.0
4.0
9-26
-------
3. The estimated annual aggregate increase in purchase price for noise abatement for
portable air compressors is presented in Table 9-18.
Table 9-18
SUMMARY OF ESTIMATED ANNUAL AGGREGATE INCREASE
IN PURCHASE PRICE
(in $ million, with 2 dBA tolerances)
Option
2
$25.0
Option
3
$20.3
Option
4
$25.4
Option
8
$23.4
Option
9
$25.0
Option
10
$20.3
Option
11
$25.4
Option
12
$23.4
4. There will be little effect on upstream component suppliers. Distributors and end
users may be affected in that alternative air sources and competitive systems will
become a more important factor in working on or moving material.
5. There will be no significant effect on factory operations.
6. No significant unemployment is expected to occur.
7. No changes in export or import patterns should occur because of noise regulations.
8. No significant impact will be transmitted to the national or a regional economy,
provided adequate lead time to compliance is allowed.
9-27
-------
Section 10
EVALUATION OF EFFECTS OF PORTABLE AIR COMPRESSOR NOISE ON
PUBLIC HEALTH AND WELFARE OF THE U.S. POPULATION
Pursuant to the Noise Control Act of 1972, EPA has selected and published noise
measures believed to be most useful for describing environmental noise and its effects on
people, independent of the source(s) of noise. In addition, information has also been pub-
lished on the noise levels "requisite to protect the health and welfare'" including personal
comfort and well being, as well as the absence of clinical symptoms (e.g., hearing loss). Using
information published in References 1 and 2. analyses were performed to evaluate the effects
of the air compressor regulation on the health and welfare of the U.S. population exposed
to construction site noise.
The approach taken for the analyses was to evaluate the effects, in terms of percent
changes, in the impact of construction site noise on U.S. population resulting from the reduc-
tion of portable air compressor noise alone and then in combination with the reduction of
truck noise. Truck noise is a major contributor to construction site noise and is currently the
subject of noise emission control. The methodology presented in Appendix B has been
applied to the specific case of construction noise to evaluate potential public health and
welfare benefits derived from portable air compressor and truck noise regulations.
The analyses considered construction of residential and nonresidential buildings, city
streets, and public works that normally occur in places where population density is high.
Heavy construction, such as highways and civil works, has been omitted from the study since
the bulk of this activity generally occurs in thinly populated areas where the extensiveness
of potential noise effects on people is minor. In the framework of the analysis, construction
is viewed as a process that can be categorized according to the type of construction, as well
as to the separate and distinct activity phases that occur.
The basic unit of construction activity is the construction site. A construction site
exists in both time and space. Four different types of construction sites were evaluated in
the analysis:
1. Domestic housing and residential.
2. Nonresidential, office buildings, hotels, hospitals, schools, government buildings,
including highrise.
10-1
-------
3. Industrial, parking garage, religious monuments, amusement and recreation, stores,
service stations, but no highrise.
4. Public works, municipal streets, and sewers.
Construction activity is generally carried out in several discrete steps, each of which
has its own mix of equipment and attendant noise output. The phases of construction
studied were those of Reference 2. The data presented in Reference 2, adopted for the
present analysis, provide all the necessary input for deriving the variation in noise output
with time. Basically, the process involved in deriving the noise history at each site consists
of identifying the equipment found at each site in each construction activity phase in
terms of:
• The number of equipment types typically present at the site in a given phase.
• The duty cycle of each type of equipment.
• The average noise level of each equipment type during the construction activity
operation.
The original information given in Reference 2 has been reviewed and revised to include
data that has since become available in Reference 32. The revisions appear in Tables 10-1 a,
b, c and d.
The usage factors presented in Tables 10-1 a through d, were combined with typical
periods of use (hours) of equipment operated for a particular task, to yield a site Leq as
measured 50 feet from the site. For the purpose of this analysis, a construction site is
viewed as a complex source in which equipment is centered at a point 50 feet from an
observer. This consideration provides a model with which to establish a base set of data.
The Leq obtained using this model was converted to an Ldn for a 24-hour day and then
converted to an annual L^n- Thus, each construction site was viewed as a complex noise
source with a fixed annual value of Ldn. The analysis was repeated for each type of site.
The human impact of construction noise was brought into the analysis by use of the
data presented in Reference 2 with regard to the number of construction sites of various
types in a number of geographical regions, as well as the population densities within the
regions. The number of sites per year was taken from Table IV of Reference 32, and the
population density data was taken from Table XI of Reference 2. For the nonresidential
10-2
-------
Table 10-1 a
USAGE FACTORS OF EQUIPMENT IN DOMESTIC HOUSING CONSTRUCTION
Equipment
Air compressor
Backhoe
Concrete mixer
Concrete pump
Concrete vibrator
Crane, derrick
Crane, mobile
Dozer
Generator
Grader
Paving Breaker
Loader
Paver
Pile driver
Pneumatic tool
Pump
Rock drill
Roller
Saw
Scraper
Shovel
Truck
(81)*
(85)
(85)
(82)
(76)
(88)
(83)
(87)
(78)
(85)
(88)
(84)
(89)
(101)
(85)
(76)
(98)
(80)
(78)
(88)
(82)
(88)
Construction phase
O O bx>
bC '£ '£ C £5
C Cti C^ JL "~1
a § i * a
<§ o 3 o> g
O W h W fr
- 0.1 - - 0.25
.0.02 0.2 - - 0.02
0.4 0.08 0.16
_ _
_ _
_ _
0.10 0.04
0.10 0.1 - - 0.04
0.4 -
0.05 - - - 0.02
0.01
0.2 0.1 - - 0.04
0.025
_ _
0.04 0.1 0.04
0.1 0.2
0.005
0.04
0.04[2]** O.l[2] 0.04(2]
0.05 - 0.01
- 0.2 -
0.04 0.1 - - 0.04
S-i "
0 £
^ ^""^
h 0) "o
r§ ^ 0
^ o £•
^^ 0)
o w d
lO ""O O
~— o
g"'sH o>
i-3 CL O
68.7
69.5
76.5
-
-
-
69.5
72.0
64.5
65.0
61.0
70.0
66.0
-
72.5
63.0
65.5
59.0
68.5
67.0
65.5
70.0
Hours at site
Leq /5Q') per site during work periods = 82. 0 dBA
24 24 40 80 402 = 208 hrs.
26 days
Total number of sites = 514,424 (Table W(a) of reference 32)
* Numbers in parentheses ( ) represent average noise levels (dBA) at 50 ft.
** Numbers in brackets [ ] represent average number of items in use, if that
number is greater than one. Blanks indicate zero or very rare usage.
10-3
-------
Table 10-1 b
USAGE FACTORS OF EQUIPMENT IN NONRESIDENTIAL CONSTRUCTION
($190K-4000K)
Equipment
Air compressor
Backhoe
Concrete mixer
Concrete pump
Concrete vibrator
Crane, derrick
Crane, mobile
Dozer
Generator
Grader
Paving breaker
Loader
Paver
Pile driver
Pneumatic tool
Pump
Rock drill
Roller
Saw
Scraper
Shovel
Truck
(81)*
(85)
(85)
(82)
(76)
(88)
(83)
(87)
(78)
(85)
(88)
(84)
(89)
(101)
(85)
(76)
(98)
(80)
(78)
(88)
(82)
(88)
Construction phase
bD
.3
:-
0>
I— 1
U
_
0.04
-
-
-
_
-
0.16
0.4[2]
0.08
-
0.16
-
-
-
-
-
-
-
0.55
-
0.16[2]
§
•r-t
1
d
o
X
w
1.0[2]**
0.16
-
-
-
-
-
0.4
1.0[2]
-
0.1
0.4
—
-
-
1.0[2]
0.04
-
-
-
0.4
0.4
g
•i— (
1
i
PM
1.0[2]
0.4
0.4
0.08
0.2
-
-
-
-
-
0.04
-
-
0.04
0.04
1. 0[2]
-
-
0.04[3]
-
-
-
§
*i-H
1
!H
W
1. 0[2]
-
0.4
0.4
0.2
0.16
0. 16 [2]
-
-
-
0.04
-
-
o.ie[2]
0. 16[2]
0.4
-
-
1.0[3]
-
-
—
If
GQ
• |H
.2
h
0.4[2]
0.04
0.16
0.08
0.04
0.04
0.04 [2]
0.16
-
0.02
0.04
0.16
0.1
0.04[2]
0.04[2]
-
0.005
0.1
-
-
-
0.16
•i
pi
?-i 0>
O -H
£
|i-|
^ «s £
*" 02 £H
^^ ^3 O
°f'£ o
hJ a o
83.5
76.5
79.0
74.5
67.0
76.0
74.0
78.0
75.0
63.5
75.0
75.0
70.0
85.0
76.0
76.5
78.0
60.5
76.5
73.0
72.0
80.0
Le_/50T\ per site during work periods =
91.0 dBA
Hours at site
80
320 320 480 160 2 = 1360 hrs.
170 days
Total number of sites = 12,710 (Tables IV(b) of reference 32)
* Numbers in parentheses () represent average noise levels (dBA) at 50 ft.
** Numbers in brackets [ ] represent average number of items if number is
greater than one. Blanks indicate zero or very rare usage.
10-4
-------
,Table 10-1 c
USAGE FACTORS OF EQUIPMENT IN INDUSTRIAL CONSTRUCTION
($30K-820K, no high-rise)
Equipment
Air compressor
Backhoe
Concrete mixer
Concrete pump
Concrete vibrator
Crane, derrick
Crane, mobile
Dozer
Generator
Grader
Paving breaker
Loader
Paver
Pile driver
Pneumatic tool
Pump
Rock drill
Roller
Saw
Scraper
Shovel
Truck
(81)*
(85)
(85)
(82)
(76)
(88)
(83)
(87)
(78)
(85)
(88)
(84)
(89)
(101)
(85)
(76)
(98)
(80)
(78)
(88)
(82)
(88)
Construction phase
o
faO VH
£3 erf
"r"1 ^
cA Cd
1 8
o w
1.0
0.04 0.16
-
-
-
-
-
0.2 0.4
0.4 0.4
0.05
0.1
0.16 0.4
-
- -
-
0.4
0.02
- -
-
0.14
0.4
0.16[2] 0.26[2]
o
•iH
ert
T3
JH
O
fc
0.4
0.4
0.4
0.05
0.2
-
-
-
-
-
0.04
-
-
0.04
0.04
1.0 [2]
-
-
0.04[2]
-
-
-
a
O
•f-t
o
at
W
0.4
-
0.16
0.16
0.1
0.04
0.08
-
-
--
0.04
-
-
-
o.i[s]**
0.4
-
-
O.l[2]
-
-
-
,
cT
.^
r*|
CO
•i-t
0.4
0.04
0.16
0.08
0.04
0.02
0.04
0.04
-
0.02
0.04
0.04
0.12
-
0.04
-
0.003
0.1
-
0.08
0.06
0.16
A
a
f-t 01
|||
3 f-( ^
T3 0 &<
^ 0)
~ CQ d
"— ' T3 O
i£- °
%'% ®
®
iJ a- o
78.0
76.5
77.5
71.0
65.5
70.0
68.0
77.5
68.5
62.5
75.0
74.5
70.5
81.0
76.0
53.0
75.0
60.5
67.5
70.5
72.0
78.5
Hours at site
Leq/50') per site during work periods =
80 320 320 480 160£
88. 0 dBA
1360 hrs.
170 days
Total number of sites = 50,839 (Tables IV(c) of reference 32)
* Numbers in parentheses () represent average noise levels (dBA) at 50 ft.
** Numbers in brackets [ ] represent average number of items in use, if that
number is greater than one. Blanks indicate zero or very rare usage.
10-5
-------
Table 10-1 d
USAGE FACTORS OF EQUIPMENT IN PUBLIC WORKS CONSTRUCTION
(Municipal streets and sewers)
Equipment
Air compressor
Backhoe
Concrete mixer
Concrete pump
Concrete vibrator
Crane, derrick
Crane, mobile
Dozer
Generator
Grader
Paving breaker
Loader
Paver
Pile driver
Pneumatic tool
Pump
Rock drill
Roller
Saw
Scraper
Shovel
Truck
(81)*
(85)
(85)
(82)
(76)
(88)
(83)
(87)
(78)
(85)
(88)
(84)
(89)
(101)
(85)
(76)
(98)
(80)
(78)
(88)
(82)
(88)
Construction phase
§
bJD !«j
'** c§
Q> 0
6 w
1.0 1.0
0.04 0.4
- -
- -
0.1
-
0.3 0.4
1.0 0.4
0.08
0.5 0.5
0.3 0.3
-
-
0.4[2]
0.02
-
-
0.08
0.04 0.4
O.ia[2] 0.16
a
•2 a
1 -
§ CO
0 f-i
0.4 0.4
0.16[2] 0.4[2]
— ~
— —
0.04 0.04
0.16
0.2
0.4 0.4
0.2
0.04
0.2
0.1 0.5
— —
0.04[2] 0.1
1.0(2] 0.4[2]
- -
0.01 0.5
0.04[2] 0.04
0.2 0.08
0.04
0.4[2] 0.2[2]
g,
•g
CO
a
fe
0.4[2]**
0.16
0.16 [2]
"""
mm
—
—
0.16
0.4
0.08
0.16
—
~
0.04
~
0.5
—
0.08
0.04
0.16 [2]
•t
t-t 0>
^ "~*
H3 § .2,
^ * 2
f^ «. W
_55 x QJ
'Q O f**
^t|~l o
•* CQ fl
§s °
^^H Q
® Q >
h4 a o
79.0
74.5
81.0
~
74.0
69.5
79.5
75.0
74.0
80.5
76.0
81.5
m^
72.5
75.5
c\ n c?
82. 5
73.5
63.5
78.0
71.0
84.5
L per site during work periods =
eq(50f)
Hours at site:
12
12
24
24
122 -
91. 0 dBA
84 hrs.
10 \ days
Total number of sites = 485,224 (Table IV(d) of reference 32)
* Numbers in parentheses () represent average noise levels (dBA) at 50 ft.
** Numbers in brackets [] represent average number of items in use, if that
number is greater than one. Blanks indicate zero or very rare usage.
10-6
-------
building category, the transfer of people from the suburbs to the central city during the
average working day was considered by adjusting the population data, consistent with the
model presented in Reference 2, which is summarized in Table XI of the reference. This
adjustment was necessary to account for the fact that most construction in cities occurs
during the working day. Thus, population estimates were obtained for 20 different cases
corresponding to the four construction types (residential, nonresidential, municipal streets
and public works) and five categories of regions.
1. Large high-density central city
2. Large low-density central city
3. Other Standard Metropolitan Statistical Areas central cities
4. Urban fringe
5. Metropolitan areas outside the urban fringe.
Two models were used for the propagation of site noise into the community. In
residential areas and other lightly built up areas, noise was assumed to be attenuated at the
rate of 6 dB per doubling of distance away from the source. Accordingly, around each site there
exists a series of annulations, each of which represent successive 3 dB areas of greater attenuation.
A mean noise level L(jn (annual L(jn) was associated with each annulus, as well as the area in
square miles. The latter figure, when multiplied by the population density typical of the region,
yielded the average number of people, (P), living within that annulus. It was assumed that
on the average, only half of these people are affected by the noise because it is reasoned
that only half of the rooms in a structure in proximity to the site face the site. This assump-
tion appears reasonable but must be recognized as being somewhat arbitrary.
In the case of the nonresidential (office) building category, a different model was
considered. For this situation it was assumed that noise confined in a built up area is
attenuated by only 3 dB per doubling of distance for the first 400 feet, due to the canyon
effect, and then attenuates at 6 dB per doubling of distance, since at that point noise is
free to decrease by classical spherical divergence. Further, it was assumed that only 25
percent of the people in each annulus were affected by the construction noise since in
most office buildings not all the rooms have outside exposure. This assumption appears
reasonable, but it is also somewhat arbitrary.
CONSTRUCTION SITE NOISE IMPACT
The impact of an environmental noise has two basic dimensions: extensiveness and inten-
sity. Extensiveness of impact is measured in terms of the total numbers of people impacted
10-7
-------
regardless of the severity of individual impact. Intensity, or severity, of an individual's
impact is measured in terms of the level of the environmental noise.
For analytic purposes, it is desirable to have a single number representing the magni-
tude of the total noise impact in terms of both extensiveness and intensity in a specific
environmental situation. With a single number descriptor of noise impact, relative changes
in impact can be described in terms of simple percentage changes of relief from an initial
value. In this method, presented in Appendix B, the intensity of an environmental noise
impact at a specific location is characterized by the Fractional Impact (FI).
In the computation of the fractional impact (FI) associated with each annulus around
a construction site for office buildings and industrial facilities, computations were performed
relative to an exterior Ldn of 65 dB rather than the 55 dB assumed for residential areas
and public work areas. The rationale for this assumption was that in office buildings
adjoining construction sites, windows are normally closed, which increases the noise
reduction between outside and inside (Reference 30). The window-closed condition
provides at least 10 dB more attenuation than does the window-open condition. Accord-
ingly, exterior levels of 65 dB in the window-closed condition and 55 dB with windows
open will generally produce identical interior noise levels.
From knowledge of the various fractional impacts and the number of people con-
tained in each annulus, the equivalent population impacted in each annulus was obtained
and then summed to obtain the total impact (Peq)-*
Computations were performed to assess the change in the equivalent population
impacted by construction site noise, relative to the new regulation condition for portable
air compressor noise when reduced to levels of 76 dBA, 73 dBA, 70 dBA, and 65 dBA at
7 meters from the compressor housing. Since new-truck noise regulations currently being
formulated will, in time, produce lower truck noise levels at construction sites, the effect
of the combined reduction of portable air compressors and new-truck noise were addi-
tionally evaluated. The benefits of reducing portable air compressor and new truck noise
levels are summarized in Table 10-2 in terms of both Peq and the percent reduction of im-
pact upon the change on U.S. population exposed to construction site noise.
To further illustrate the significant benefits and relief afforded the population by
reducing new portable air compressor noise levels, Figure 10-1 has been prepared from the
data of Table 10-2. As shown in Figure 10-1, a sizeable reduction (approximately 15
percent) in the magnitude of the impact by construction site noise is achieved by regulating
Peq is numerically equal to the equivalent number of people having a fraction impact
equal to unity (100 percent impacted). See Appendix B for further details.
10-8
-------
Table 10-2
SUMMARY OF BENEFITS TO THE POPULATION IMPACTED
BY CONSTRUCTION SITE NOISE RESULTING FROM REGULATION
OF PORTABLE AIR COMPRESSOR AND TRUCK NOISE
Baseline data — — — - — —
Only air compressors reduced:
a) 76 dBA T—
b) 73 dBA
c) 70 dBA —
d) 65 dBA
Trucks reduced 83 dBA
a) Air compressors @ 76 dBA
Trucks reduced 75 dBA
a) Air compressors @ 76 dBA
1,245,622
1,062,800
1,053,810
1,049,266
1,046,133
781,000
677,660
Percent
Reduction
14.7
15.4
15.8
16.0
37.3
45.6
portable air compressor noise to 76 dBA; more stringent regulation of the air compressor
is not warranted at this time due to the little (approximately 1 percent) added health and
welfare benefits.
The results, shown in Figure 10-1 and Table 10-2, derived from the regulation of new
portable air compressors and new trucks are time dependent; that is, the benefits accrued
occur in time as the current unregulated compressor and truck population is replaced by
quiet regulated units. Figure 10-2 illustrates the magnitude by which the health and welfare
benefits accrue in time using the assumption that quiet portable air compressors and trucks
replace unquieted units at the rate of 10 percent per year.
The data clearly demonstrates that the reduction of portable air compressor noise to
an average of 76 dBA at 7,meters produces significant and desirable relief to the population
from construction site noise. In terms of acoustic energy contribution to construction site
noise, Table 10-3 shows that the reduction of portable air compressor noise to 76 dBA
reduces its energy contribution to nonresidential construction site noise (present worst case)
by 15.8 percent, for a total site contribution of approximately 1.0 percent.
10-9
-------
90
ta
85
<
80
\
8
DC
-
£ 75
0
ui
0 70
8
-
§
ff
u
65
i
t
20
30
PERCENT REDUCTION IN THE IMPACT
OF CONSTRUCTION SITE NOISE
Figure 10-1. Effect of Portable Air Compressor Noise Reduction
on the U. S. Public Impacted by Construction Site Noise
10-10
-------
50 —
40 -
o
< LU
a. u)
^ O
30 -
§ I 20
UJ CO
oc z
UJ U.
01
o.
10 -
PORTABLE AIR COMPRESSOR
AND TRUCK NOISE REGULATION
PORTABLE COMPRESSOR
NOISE REGULATION
I
I
I
I
I
1976 1978 1980 1982 1984 1986 1988
YEAR
Figure 10-2. Construction Site Noise Impact Reduction Caused by
Portable Air Compressor and Truck Noise Regulation
10-11
-------
Table 10-3
CONTRIBUTION OF PORTABLE AIR COMPRESSOR NOISE
TO CONSTRUCTION SITE NOISE
Site
Residential
Public works
Industrial
Nonresidential
Percent* of site noise
Compressor
Noise
at 88 dBA**
4.6
6.1
10.0
16.9
Compressor
Noise
at 76 dBA
.3
.4
.6
1.1
Rank* at site
Compressor
Noise
at 88 dBA**
7th
7th
3rd
2nd
Compressor
Noise
at 76 dBA
16th
16th
17th
17th
* On an energy basis
** Current average level at 7 meters of all compressors.
The data show the decreasing importance of portable air compressors (in terms of total
emitted acoustic energy) from the second most predominant construction site noise source
after trucks (at present) to the 16th noisiest piece of equipment comprising the hardware
mix of 20 pieces of equipment typically used at construction sites.
Further public health and welfare analyses were performed to assess the benefits
derived by splitting the portable air compressor population at 250 cfm and reducing noise
of compressors larger than 250 cfm to a different level. Table 10-4 lists the case studied.
Table 10-4
PORTABLE AIR COMPRESSOR NOISE REDUCED BY CATEGORY
Air flow capacity
(cfm)
Reduced noise level
(dBA)
<250
>250
76
78
10-12
-------
The rationale for this case study is as follows:
1. Eighty-two percent of the portable air compressors sold (by 1972 sales figures)
have air flow capacity of less than 250 cfm.
2. Many of the portable air compressors in the 18 percent greater than 250 cfm
category are used in remote areas where the impact on public health and welfare
is minimal.
3. Data indicate it is more difficult to quiet large portable air compressors.
4. The mean noise level of the population of quiet portable air compressors in the
marketplace today, with flow capacity greater than 250 cfm, is 77.9 dBA.
The analysis demonstrates a resultant 0.1 percentage point loss of effectiveness; that
is, a 14.6-percent impact relief from construction site noise as compared with the 14.7-
percent relief when all portable air compressors are reduced to 76 dBA.
ACTUAL POPULATION EXPOSED TO CONSTRUCTION SITE NOISE
To further assess the benefits of reducing portable air compressor and truck noise in
terms of the reduction in actual population exposed to construction site noise, the cumula-
tive number of people exposed to construction site noise levels above Ldn 55, 60, 65, 70,
and 75 was determined for:
• No construction equipment noise reduction, i.e., today's equipment noise levels.
• Portable air compressors reduced to 76 dBA.
• Portable air compressors reduced to 76 dBA and trucks (concrete mixers and dump
trucks) reduced to 83 dBA.
The estimated cumulative number of people currently exposed to construction site
noise and the attendant reduction in the number of people exposed to reduced portable
air compressor and truck noise levels is tabulated in Table 10-5. As shown, the reduction of
portable air compressor noise alone reduces the number of people exposed to levels above
Ldn 55 (the noise level identified as protective of health and welfare with an adequate
margin of safety) by 4.2 million, while reduction of both portable air compressor and
truck noise reduces the number of people exposed by 7.4 million. With portable air
10-13
-------
Table 10-5
EFFECT OF PORTABLE AIR COMPRESSOR AND TRUCK NOISE
EMISSION REGULATIONS ON THE U. S. POPULATION
EXPOSED TO CONSTRUCTION SITE NOISE
Ldn
55
60
65
70
75
No
Regulation
Cumulative
Population
exposed to
Construction
Site Noise
27,457,000
7,723,000
2,079,000
587,000
93,000
Construction Equipment
Regulated
Portable Air Compressors
Regulated*
Cumulative
Population
Exposed
23,242,000
6,456,000
1,714,000
472,000
61,000
A
4,215,000
1,267,000
365,000
115,000
32, 000
Portable Air Compressors
and Trucks Regulated**
Cumulative
Population
Exposed
20,045,000
5,569,000
1,526,000
412,000
50,000
A
7,412,000
2,154,000
553,000
175,000
43,000
* 76 dBA @ 7m (23 ft.)
** Portable air compressors regulated at 76 dBA @ 7m (23 ft.) and trucks
regulated at 83 dBA @ 15.2m (50 ft.)
compressor and truck noise reduced, 20 million people will remain exposed to construc-
tion site noise levels above Ldn 55; this being so because the 18 other pieces of construction
equipment continue to contribute significant acoustic energy to the site environment.
10-14
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Section 11
ENFORCEMENT
Enforcement of new product noise emission standards applicable to new portable air
compressors will be accomplished through:
• Production verification testing of compressor configurations.
• Assembly process testing using selective enforcement auditing of production com-
pressors and
• In-use compliance programs.
The predominant portion of any production verification testing and assembly process
testing will be carried out by the manufacturer and audited or confirmed by EPA
personnel, as necessary.
Any test used for production verification testing and any test used for assembly pro-
cess testing of production compressors should be the same test as that specified in the regu-
lations or correlative so that compliance may be accurately determined. The standard
measurement methodology, which'can be used both for production verification testing and
assembly process testing of portable air compressors, is a modified version of the CAGI/
PNEUROP test method that appears in Section 6.
Analyses have been performed to assess potential product verification and selective
enforcement auditing testing costs. Appendix C presents the estimates and lists the under-
lying assumptions used in the analyses.
PRODUCTION VERIFICATION
Production verification is the testing of early production models by a manufacturer or
by EPA to verify that a manufacturer has developed the necessary technology and is capable
of applying the technology in a manufacturing process.
11-1
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Production verification does not involve any formal EPA approval or issuance of certifi-
cates subsequent to manufacturer testing, nor is any extensive testing required by EPA. A
compressor configuration must undergo production verification prior to or soon after its
distribution in commerce. Like configurations may be grouped into'a category, as defined
in the regulations. A compressor model would be considered to have been production verified
after the manufacturer has shown, based on the application of the noise measurement testing
methodology, that a configuration or configurations of that model conform to the standard.
Production verification testing of all configurations produced by a manufacturer may not be
required if a manufacturer can show that the noise levels of some configurations in a category
are consistently higher than others in a category. In such a case, the noisiest configuration
would be the only configuration requiring verification. Manufacturers must reverify when-
ever they implement engineering changes to their products that are likely to adversely affect
noise emissions. Additionally, some further testing on a continuing or other basis of pro-
duction products may be necessary to assure that all products manufactured conform to the
standards.
Production verification provides EPA with confidence that production models will con-
form to the standards and also limits the possibility that nonconforming compressors will be
distributed in commerce. If the possibility exists that subsequent models may not conform
to the standard, selective enforcement auditing may be used to determine whether production
compressors continue to actually conform to the standard.
Selective Enforcement Auditing
The regulations provide for sample testing based on an audit of production compressors
(Selective Enforcement Auditing). Selective Enforcement Auditing (SEA) is the term used
to describe the testing of a statistical sample of production compressors, from a particular
compressor category or configuration selected, to determine whether production compressors
conform to the standard and to provide the basis for further action in the case of nonconform-
ity. SEA testing is performed pursuant to an administrative request in accordance with the
proposed test procedure.
The sampling strategy adopted by EPA does not attempt to impose a quality control or
quality assurance scheme upon a manufacturer but merely audits the conformity of his
products.
Testing is initiated by a test request that will be issued to the manufacturer by the
Assistant Administrator for Enforcement or his designated representative. A test request
may be directed to a category, a configuration, or several configurations in a category. The
test request will require the manufacturer to test a sample of compressors of the specified
category or configuration produced at a specified plant.
11-2
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An important influencing factor regarding the decisions of the Administrator to issue a
test request is whether the manufacturer is conducting noise emission testing of production
compressors under his own quality control scheme. If a manufacturer can provide evidence
that his compressors are meeting standards based on test and sampling methods acceptable to
EPA, issuance of a test request may not be necessary.
The general type of sampling strategy developed by EPA employs attributes-type sampling
plans applied to a specific number of batches of compressors. Under inspection by attributes,
items are inspected or tested to determine whether they meet the prescribed specification.
The basic decision criterion is the number of compressors having parameters that meet the
specification rather than the average value of some parameter. The particular specification
for compressors is the noise emission standard established by regulation.
Two types of sampling plans for inspection of batches are employed, single and
multiple sampling. For single sampling, only one test sample of compressors is selected
from the batch subject to testing. Single sampling is used when the batch size ranges
from 4 to 15; while multiple sampling is used for batch sizes over 15 compressors. Multiple
sampling differs from single sampling in that small consecutive test samples are drawn from a
batch rather than one large sample. Multiple sampling offers the advantage of keeping the
number of compressors tested to a minimum when the compressors are meeting the standard.
The samples required under the single sampling plan range from 3 to 4 per batch, depending
on the batch size. Under the multiple plan sample size ranges from 2 to 14.
The sampling plans are arranged according to the size of the batch from which a sample
or samples are to be drawn. Each plan specifies the sample size and acceptance and rejection
numbers associated with an acceptable quality level (AQL) of 10 percent. As applied to
compressor noise emissions, the AQL is the maximum percentage of compressors that fail to
meet the noise emission standard; but, for purposes of sampling, inspection can be considered
acceptable. An AQL of 10 percent was chosen to take into account some test variability and
random production errors.
The sampling plans provide for audit of a manufacturer's product noise emission stan-
dard conformance as based on tests performed on a sequence of production batches of his
products. As a result of the acceptance or rejection of the prescribed number of batches,
the determination is made as to whether the manufacturer is producing compressors within
the prescribed acceptable quality level of 10 percent.
Batches tested are accepted or rejected based on tests performed on samples of com-
pressors. The number of n on complying compressors in a sample is compared to the accep-
tance and rejection numbers for the appropriate sampling plans. If the number of failures is
less than or equal to the acceptance number, the batch is said to be accepted. On the other
11-3
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hand if the number of failing compressors in the sample is greater than or equal to the rejec-
tion number, then the batch is said to be rejected. The probability that a batch will be
accepted if the percentage of noncomplying compressors is less than the AQL is high. The
probability that a batch will be rejected if the actual number of noncomplying compressors
is greater than the AQL increases as the percentage of noncomplying compressors increases.
When the sampling strategy involves a multiple sampling plan, there may be some
instances in which the number of failures in a test sample may not allow acceptance or
rejection of a batch. When this occurs continued testing may be required until a decision
can be made to either accept or reject a batch.
Regardless of whether a batch is accepted or rejected, noncomplying compressors will
have to be repaired or adjusted and will have to pass a retest before they can be distributed
in commerce.
The fact that one batch of compressors is accepted or rejected does not provide suffi-
cient information as to whether tffe particular category or configuration(s) selected for testing
is in compliance with the standard. This is because the number of compressors tested in
inspecting one batch is not of a large enough sample to determine production quality on an
extended basis. To provide a large enough sample on which to base production quality, the
manufacturer must inspect a sequence of batches. As in the case for the sampling plans for
inspecting batches, the sequences of batches that must be inspected are arranged according to
the size of the batch. Associated with each batch size is the number of consecutive batches
required to be inspected and batch sequence acceptance and rejection numbers. Pairs of
consecutive batches are inspected and the number of rejected batches are compared to the
batch sequence acceptance and rejection numbers. If the number of accepted batches is less
than or equal to the batch sequence acceptance number, the manufacturer will not be required,
at that time to conduct further sampling and testing of the category or configuration selected
pursuant to the initial test request. If the number of rejected batches is greater than the batch
sequence acceptance number but less than the rejection number, the manufacturer must con-
tinue to inspect consecutive batches. If the number of rejected batches is equal to or greater
than the batch sequence rejection number, the manufacturer may be required to institute
100 percent testing for all compressors identified in the request.
The sampling and batch sequence inspection plans in this regulation were designed so
that the maximum manufacturer's risk is 5 percent. That is, if the percentage of noncomply-
ing compressors a manufacturer produces is 10 percent or less, there is a maximum probability
of 0.05 that he will be requested to institute 100 percent testing.
Since the number of compressors tested in response to a test request may vary consider-
ably, a fixed time limit cannot be placed on completing all testing. The proposed approach
-------
is to establish the time limit for complying with an SEA request on the basis of a maximum
specified test time per compressor, taking transportation requirements, if any, into consider-
ation. The manufacturer would be allowed a reasonable amount of time for transport of
compressors to a test facility if one were not available at the assembly plant.
The sampling plans developed by EPA for use in the regulations can be characterized by
operating characteristic (OC) curves. The OC curves for the EPA plans are presented in
Figure 11-1, which graphically demonstrates how the probability of accepting a batch sequence
varies with the percentage of noncomplying compressors. The maximum manufacturer's risk
O!
o-
0)
V)
to
CD
Q.
O
u
8
u
3
V)
"5
O
£
A =
B =
C =
D =
Batch Size
4 to 8
9 to 15
16 to 25
26 and greater
100
Percentage Noncomplying
Figure 11-1. Operating Characteristic Curves for Sampling Plans
11-5
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previously referred to can be read directly from the OC curves. For each batch size, the
manufacturer's risk is one minus the probability of accepting the batch sequence when the
percentage nonconforming is 10 percent. The consumer's risk, which is the probability of
a batch sequence being accepted when the percentage nonconforming exceeds the AQL, can
also be read directly from the OC curves.
If a manufacturer can provide evidence that his compressors are meeting the standard
using tests and sampling methods acceptable to EPA, issuance of a test request may not be
necessary. For batch-type sampling plans, EPA will judge the acceptability of a manufac-
turer's sampling plan in terms of the OC curve or curves characterizing the plan. The OC
curve or curves for a manufacturer's sampling plan must be comparable to the OC curves for
the EPA plans.
If a manufacturer employs a continuous-type sampling plan (such as Department of
Defense Handbook HI06, "Multi-level Continuous Sampling Procedure and Table for
Inspection by Attributes"), then the average outgoing quality limit (AOQL) must not exceed
10 percent, where the AOQL is the worst average outgoing quality that will result from
employing a given sampling plan, regardless of the incoming quality.
Both attributes and variable type sampling plans will be considered by EPA for use by
a manufacturer in his quality control scheme. In the event a manufacturer elects to use a
variables-type plan, he must demonstrate to EPA that the sampling plan is appropriate for
the type of distribution that noise emissions from compressors manufactured by him exhibit.
To demonstrate suitability of either an attribute- or variable-type sampling plan, the manu-
facturer must provide data to EPA on test results from a sufficiently large sample of com-
pressors to enable statistically valid conclusions to be drawn regarding the underlying distri-
bution. He must also include the analysis of the data.
It is the manufacturer's responsibility to derive the OC curves or AOQL for his plan or
plans for presentation to EPA before EPA will make a judgment relative to the acceptability
of both the plan and test results, on the basis of such a plan, as an alternative to issuance of
a test request
ENFORCEMENT ACTION
The prohibitions in the Act would be violated in the following instances:
1. If the manufacturer fails to properly verify the conformance of production com-
pressors.
11-6
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2. If it is determined, on the basis of selective enforcement audit testing or other
information, that nonconforming production compressors are knowingly being
distributed into commerce.
3. If the manufacturer fails to comply with an Administrator's order specifying appro-
priate relief where nonconformity is determined.
4. If the noise control system of a compressor is "tampered with," as defined in the
Act.
Remedies
In addition to the criminal penalties, fines and imprisonment, associated with violations
of the prohibitions of the Act, the Administrator has the option of issuing an order specify-
ing such relief as he determines necessary to protect the public health and welfare. Such
orders could require that a manufacturer recall products distributed into commerce not in
conformity with the regulations, whether or not the manufacturer had knowledge of the
nonconformity. Recall orders will be issued in situations in which selective enforcement
testing demonstrates that compressors of a particular configuration that do not conform
with the applicable emission standard have been distributed in commerce.
The Administrator may also issue an order requiring the manufacturer to cease distri-
bution in commerce of compressors when the requirements of production verification have
not been met.
Any orders would be issued only after manufacturers had been afforded notice and an
opportunity for a hearing.
Labeling
The label will provide notice to buyers and users that the product is sold in conformity
with the regulations and that the compressor is equipped with noise attenuation devices,
which should not be removed or rendered inoperative, as prohibited under Federal law. The
label also states that the use of a product that has been tampered with is prohibited.
11-7
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In-Use Compliance
The intent behind this requirement is to ensure that the public health and welfare
benefits derived from the portable air compressor standard are fully achieved over time.
The Agency maintains that product noise emission standards developed to protect public
health and welfare must not degrade during the product's life. However, where degradation
cannot be reasonably prevented through periodic preventive maintenance and repair,
standards may include a degradation allowance.
Currently, no data are available to determine whether and to what degree the noise
from a properly maintained and repaired portable air compressor would degrade in time.
Accordingly, the Agency is reserving a section for useful life requirements in the regulation
and will defer action on setting a useful life standard until necessary and sufficient data are
collected on which to base a standard. The delay in promulgating a useful life standard
should not be construed as a deemphasis of this requirement, but merely as a means to
assure that an accurate and fair useful life requirement may be imposed.
The manufacturer is required (by Section 6 (d) (1) of the Act) to warrant to the first
purchaser and each subsequent purchaser that the compressor was designed, built, and
equipped to conform at the time of sale to the Federal noise emission standards. Thus, the
manufacturer is required to remedy all defects in design, assembly, or in any part of the
system, that at the time of retail sale caused the Federal noise emission standard to be
exceeded. Although the warranty covers only date-of-sale nonconformity, the consumer
may make a claim under the warranty at any time during the life of the product, as long as
he can establish noncompliance on the date of sale.
Recall is generally the appropriate remedy (under Section 11 (d) (1)) to require the
manufacturer to repair or replace a class of compressors that fails to conform to Federal
standards at the time of sale. Such recall may be used, for example, when products are
discovered in use with defects relating back to the date of sale that would cause
noncompliance.
Tampering with (removing or rendering inoperative) the noise control devices and ele-
ments of design, so that Federal noise emission levels are exceeded, is prohibited under
Section 10 (2) (A) of the Act. The use of a product after it has been tampered with is also
prohibited.
Finally, manufacturers are required (pursuant to regulations under Section 6 (c) (1)) to
provide instructions to purchasers specifying the maintenance, use, and repair necessary to
minimize or eliminate any possible degradation from the initial noise emission levels.
11-8
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Section 12
ENVIRONMENTAL EFFECTS OF NOISE EMISSION REGULATION
OF PORTABLE AIR COMPRESSORS
IMPACT RELATED TO ACOUSTICAL ENVIRONMENT
The regulation will limit the magnitude of noise emission of newly manufactured por-
table air compressors and will produce a 14.7 percent reduction in the impact of construction
site noise on people. When viewed in concert with new truck noise regulations, a reduction
in total impact of 45 percent is anticipated when the current population of compressors
and trucks is replaced by quiet units. This regulation is a first step in a comprehensive
noise abatement effort aimed at reducing the total environmental noise to which the popu-
lation is subjected. The composite impact of all Federal noise emission regulations will be
aimed at a level of environmental noise consistent with protecting human health and welfare.
IMPACT RELATED TO LAND
Portable air compressor regulations will have no adverse effects relative to land.
IMPACT RELATED TO WATER
Portable air compressor regulations will have no adverse effects on water quality or
supply.
IMPACT RELATED TO AIR
These regulations will have no adverse impact on air quality.
There exists a possibility of market shifts from gasoline-powered to diesel-powered
portable air compressors. If these shifts occur in favor of diesel-engine powered compressors,
total air emissions might be reduced since diesel engines produce less pollutants as the
byproduct of combustion than do gasoline engines.
12-1
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IMPACT RELATED TO ENERGY
Portable air compressor regulations will have little, if any, impact on fuel consumption.
There exists considerable disagreement among the industry regarding any potential
increase in fuel use by quieted portable air compressors. It is EPA's belief that fuel con-
sumption increases that may result from, increased cooling requirements will be offset
through the use of more efficient fans in the quieted compressors.
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REFERENCES
1. "Information on Levels of Environmental Noise Requisite to Protect Public Health
and Welfare with an Adequate Margin of Safety," Environmental Protection Agency,
550/9-74-004, March 1974.
2. "Noise from Construction Equipment and Operations, Building Equipment and Home
Appliances," Environmental Protection Agency NTID 300.1, December 1971.
3. "Report to the President and Congress on Noise," 92d Congress, 2d Session, 92-63,
February 1972.
4. Patterson, W. N., et.al, "Specialty Construction Trucks: Noise and Cost of Abate-
ment," Bolt Beranek and Newman, Report No. 2566a, September 1973.
5. Freeze, T. W., et al, "Portable Air Compressor: The Costs, Benefits and Penalties of
Reducing Their Noise," EPA Contract No. 68-01-1539, Bolt Beranek and Newman,
Report No. 2566c, March 1, 1974.
6. Patterson, W.N., et al, "Portable Air Compressor Noise," Bolt Beranek and Newman,
Report No. 2795a, March 29, 1974.
7. Patterson, W. N., et al, "Portable Air Compressor Noise: Diagnosis and Control,"
Bolt Beranek and Newman, Report No. 2795b, March 29, 1974.
8. Kearney, A. T., "A Study to Determine the Economic Impact of Noise Emission
Standards in the Construction Equipment Industry: Portable Air Compressor Report.'
9. Steele, S. and the Noise Information Program, "A Study of Local and State Laws for
the Noise of Construction Equipment," EPA Contract No. 68-01-2229, Informatics,
Inc., Rockville, Md., May 1, 1974.
10. The Noise Information Program, "Foreign Regulations for Construction Equipment:
A Status Report," EPA Contract No. 68-01-1894, Informatics, Inc., Rockville, Md.,
March 25, 1974.
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11. Holmer, C.I., "Measurement Methodology and Supporting Documentation for Portable
Air Compressors," National Bureau of Standards, Washington, D.C., January 1975.
12. "Identification of Products as Major Sources of Noise," Federal Register, Vol. 39, No.
121, June 21, 1974.
13. "Standards on Noise Measurement, Rating Schemes, and Definitions: A Compilation,"
National Bureau of Standards, Washington, D.C., Publication 386, November 1973.
14. "Exterior Sound Level Measurement Procedure for Powered Mobile Construction
Equipment," Proposed SAE Recommended Practice x588.
15. "Construction Site Sound Level Measurements," Proposed SEA Recommended
Practice.
16. "CAGI-PNEUROP Test Code for the Measurement of Sound from Pneumatic Equip-
ment," ANSI 85,1-1972, 1969.
17. Peterson, A.P.G. and Gross, Jr., E.E., Handbook of Noise Measurement, General
Radio Co., 1972.
18. Griffiths, Lt. Col., J.D., "The Design of a Low Cost Sound Level Meter," USAF
TR-74-6, EPA 550/9-74-008, April 1974.
19. Francois, P., and Fleury, M., "Noise Measurement on Mobile Compressors for
Construction Sites," Cour, de la Norm., No. 220-VII-VIII: 467-474 (in French), 1971.
20. Oncley, P.B., "Correction Procedure for Outdoor Noise Measurement," Inter-Noise
72 Proceedings, Washington, D.C., 1972.
21. Bettis, R.A., and Sexton, M.X., "The Effect of Test Site Topography in Vehicle Noise
Measurement," presented at the 85th Meeting of the Acoustical Society of America,
Boston, Mass., 1973.
22. Anderson, G.S., Miller, R.L., and Schwartz, R.M., " 1972 Noise Levels and Noise
Models for Urban Truck Traffic: West Side Highway Project," Bolt Beranek and
Newman Report No. 2519A, 1973.
23. Wiener, P.M., Malme, C.I., and Gogos, C.M., "Sound Propagation in Urban Areas,"
Journal of the Acoustical Society of America, 37: 739-747, 1965.
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24. Kurze, U.J., and Anderson G.S., "Sound Attenuation by Barriers," App. Acoust., 4:
35-53, 1971.
25. Kessler, P.M., "Portable Compressor Noise Reduction-Final Report," Ingersoll Rand
Research, Inc., TND-362, August 1968.
26. Hinck, D.C. and McGahan, W.A., "Sound Reduction of Large Portable Air Compressors,"
Ingersoll Rand Research Inc.
27. Heinrick Flottman,'K.G., letter to Informatics, February 5, 1974.
28. "Public Health and Welfare Criteria for Noise," Environmental Protection Agency
Report 550/9-73-002, July 1973.
29. "Standard for the Calculation of the Articulation Index," ANSI S3.5-1969.
30. "House Noise - Reduction Measurements for Use in Studies of Aircraft Flyover Noise,"
Society of Automotive Engineers, Inc., AIR 1081, October 1971.
31. "Construction Noise Survey," Bureau of Noise Control, New York Department of
Environmental Conservation, April 1974.
32. Patterson, W.N., et al, "Regulation of Construction Activity Noise," Bolt Beranek and
Newman Report No. 2887, November 27, 1974.
33. General Electric TEMPO, "Proposed New Portable Air Compressor Regulation:
Supplementary Economic Impact Analysis." June 1975.
34. "Population Distribution of The United States as a Function of Outdoor Noise Level,"
Environmental Protection Agency Report 550/9-74-009, June 1974.
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APPENDIX A
DOCKET ANALYSIS
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Appendix A
DOCKET ANALYSIS
INTRODUCTION
Environmental Protection Agency is committed by statute and policy to
in-depth public participation in the decision making process for its environmental
regulations. This policy encourages and solicits contributions from the public
on technology, costs, health and welfare and economic impact or benefits and any
other attributes of the particular subject. Contributions are desired from as
many diverse views as are possible, and when such information, after thorough
analysis by the Agency, indicates a need for change, appropriate action is taken
to insure that the regulation being promulgated incorporates such changes.
Pursuant to the Agency's policy, three opportunities were provided for the
public to comment on the proposed noise emission regulation for portable air
compressors. On October 29, 1974, concomitant with publication of the Notice
of Proposed Rulemaking (NPRM) for portable air compressors (39 F.R. 38186),
a docket was opened to receive written public comments regarding the NPRM.
The period for public comment extended from October 29, 1974, to December 31,
1974, to allow interested persons 2 months to formulate comments and respond.
On February 18, 1975, a public hearing on the proposed regulation was held
in Arlington, Virginia, to provide additional opportunities for the public to com-
ment on the proposed rulemaking. This was followed by a second public hearing
on February 25, 1975, in San Francisco, California. A public hearing docket was
opened to accommodate written materials submitted to the Agency pursuant to
the hearings. This docket closed on March 10, 1975.
All public comments received by EPA/ONAC in the form of written docket
submissions, as well as from public hearing testimony, have been reviewed and
analyzed by the Agency. Where the analysis indicated changes were appropriate,
the Agency incorporated these into the regulation being promulgated.
Summarized in this section are the comments received by the Agency result-
ing from public participation in the portable air compressor rulemaking. Also
included are the Agency's responses to the comments. The docket analysis is
organized into two sections. Section 1 identifies and summarizes the major
issues raised by the various commenters. The issues have been separated into
five categories: (1) Technical, (2) Health and Welfare, (3) Economic, (4) Legal,
A-l
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and (5) Miscellaneous. Each issue is identified by number and is followed
by a list of those who raised the issue. Opposite the name of each
individual is a descriptor referring to the location of the comment in the
Agency's records. Comments received as submissions to the NPRM
docket are identified by a number preceded by the letter C, while those
arising from public hearings are identified by the word "Transcript."
Section 2 presents the Agency's response to each issue raised in Section 1.
All dockets and public hearing transcripts are available for public
inspection between 9:00 A.M. and 4:30 P.M. at:
EPA/ONAC
Room 1105, Crystal Mall #2
1921 Jefferson Davis Highway
Arlington, Virginia
A-2
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PORTABLE AIR COMPRESSOR REGULATION
DOCKET ANALYSIS
TABLE OF CONTENTS
LIST OF ISSUES
1. Technology A-4
2. Health and Welfare A-ll
3. Economics A-13
4. Enforcement A-21
5. Miscellaneous A-29
RESPONSE TO ISSUES
1. Technology A-30
2. Health and Welfare A-40
3. Economics A-42
4. Enforcement A-50
5. Miscellaneous A-GC
A-3
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1. TECHNOLOGY
Issue Docket No.
1.1 COMMENT;
C036
Transcript
1.2 COMMENT;
Transcript
Transcript
1.3 COMMENT;
C039
C036
Transcript
Transcript
Transcript
Transcript
Originator
A 76 dBA limit does not represent cur-
rently available technology.
Richard Gimer
Compressed Air and Gas Institute
Richard Gimer
Compressed Air and Gas Institute
The technology to quiet portable air com-
pressors is available.
J. A. Mills
Director of Research
Industrial Noise Services, Inc.
Richard S. Anderson
Vice President
General Acoustics Corporation
Data relating to degradation of noise
emission characteristics is insufficient to
predict degradation patterns for air com-
pressor's.
F. A. Dellecave
Ingersoil-Rand Corporation
Richard Gimer
Compressed Air and Gas Institute
Richard Gimer
Compressed Air and Gas Institute
Richard Ostwald
Engineer
Gordon Smith and Company
Richard Geney
Atlas Cop co
Lawrence H. Hodges
J. I. Case Co.
A-4
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Issue
1.4
1.5
1.6
1.7
Docket No.
COMMENT:
C033
Transcript
Transcript
COMMENT:
Transcript
COMMENT:
Transcript
Transcript
Transcript
Transcript
COMMENT;
C015
C036
Transcript
Originator
Fuel consumption can be expected to increase
as a result of the regulation.
R. D. Harlow
Schramm, Inc.
Robert Harlow
Schramm, Inc.
H. T. Larmore
CIMA
Fuel consumption may be expected to remain
the same or decrease as a result of the usage
of high efficiency fans.
Paul Laesch
Sullair Corporation
Quieting technology is not the same for all
sizes and configurations of air compressors.
Paul Laesch
Sullair Corporation
Richard Gimer
CAGI
William Heckenkamp
Gardner-Denver Company
Richard Geney
Atlas Copco
The availability of quiet engines is a problem
found by manufacturers in their efforts to com-
ply with the regulation.
C. M. Copeland
P. K. Lindsay Co.
Richard Gimer
CAGI
Richard Gimer
CAGI
A-5
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Issue
Docket No.
Originator
1.8
1.9
1.10
1.11
Transcript
Transcript
Transcript
COMMENT;
Transcript
C032
COMMENT;
CO 38
COMMENT:
Transcript
COMMENT;
C036
Transcript
Transcript
Transcript
William Price
Worthington Compressors, Inc.
William Heckenkamp
Gardner-Denver Company
Paul Laesch
Sullair Corpration
"Band aid" measures for controlling noise
emissions are more expensive than integrated
design changes.
Lawrence H. Hodges
J. I. Case Company
D. E. Kipley
Gardner-Denver Company
Portable air compressor noise should be
measured in terms of C-weighted decibels.
Don L. Kerstetter
Pennsylvania Dept. of Environmental
Resources
Portable air compressors should be required
to have cut off devices for shutdown when access
doors are opened.
Alvin Greenwald
Private Citizen
Problems with component parts availability
may affect manufacturers' abilities to comply
with the effective date of the regulation.
Richard Gimer
CAGI
Richard Gimer
CAGI
William Price
Worthington Compressors, Inc.
Richard Ostwald
Gordon Smith and Company
A-6
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Issue
Docket No.
Transcript
1.12 COMMENT;
C017
C023
C036
Transcript
1.13 COMMENT;
C023
1.14 COMMENT;
C031
C036
1.15 COMMENT;
C032
C040
COS 6
Originator
Paul Laesch
Sullair Corporation
EPA measurement methodology should be
compatible with proposed international
methodology.
William W. Lang
Institute of Noise Control Engineering
N. J. E. Hartwell
Perkins Engine Company
Richard Gimer
CAGI
George Diehl
Inger soil -Rand Company
The test specification for a fifth microphone
above the compressor should be reconsidered
N. J. E. Hartwell
Perkins Engine Company
There is no separately identifiable "noise
control system" per se for portable air com-
pressors
A. J. Cox
CIMA
-Richard Gimer
CAGI
The regulation should provide for a simpli-
fied manufacturer pre-production testing
procedure
D. E. Kipley
Gardner-Denver Company
Joseph O'Neill
Quincy Compressor
Richard Gimer
CAGI
A-7
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Issue Docket No. Originator
1.16 COMMENT: The present method for classification of
portable air compressors should be simpli-
fied to accommodate small volume production
COS7 William Price
Worthington Compressors, Inc.
COS9 F. A. DelleCave
Ingersoll Rand
C036 Richard Gimer
CAGI
Transcript William Price
Worthington Compressors, Inc.
Transcript Lawrence H, Hodges
J. I. Case Company
Transcript Robert L. Grievell
Koehring Company
1.17 COMMENT; In order to comply with the regulation,
manufacturers must design for well below
the standard.
C009 D. E. Kipley
Gardner-Denver Company
C010 Richard Gimer
CAGI
C016 Richard Ostwald
Gordon Smith and Company
C032 D. E. Kipley
Gardner-Denver Company
COS3 R. D. Harlow
Schramm, Inc.
C037 W. S. Price
Worthington Compressors, Inc.
COS9 F. D. Dellecave
Ingersoll-Rand
A-8
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Issue Docket No.
C040
C036
Transcript
Transcript
Transcript
Transcript
Transcript
1.18 COMMENT:
Transcript
1.19 COMMENT;
Transcript
Transcript
1.20 COMMENT;
Transcript
Transcript
1.21 COMMENT:
Originator
Bruce J. Smith
Bucyrus-Erie
Richard Gimer
CAGI
Richard Gimer
CAGI
Richard Ostwald
Gordon Smith and Company
William Heckenkamp
Gardner-Denver Company
William Price
Worthington Compressors, Inc.
Richard Geney
Atlas Copco
A single incident maximum dB(C) level
should be included in the regulation
Alvin Greenwald
Private Citizen
The EPA measurement methodology is not
suitable for in-use testing at a construction
site
Robert Levy
City of San Francisco
John W. Ross, Jr.
City and County of San Francisco
The Agency neglected in its background
studies to investigate of-test machines
larger than 1200 cfm
Richard Geney
Atlas-Copco
Paul Laesch
Sullair Corporation
A conflict between noise suppression technology and
safety considerations may exist regarding the flame
retardant properties of acoustical insulation laggings
A-9
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Issue Docket No.
Transcript
1.22 COMMENT;
Transcript
1.23 .COMMENT:
Transcript
Originator
Paul Laesch
Sullair Corporation
The regulation should include controls of
pure tone noise from portable air com-
pressors
Alvin Greenwald
Private Citizen
A tolerance in the standard should be allowed
on field tests to account for environmental
and instrumentation variance likely to occur
when portable air compressors are tested in
environments different from the controlled
environment of the manufacturer's facility
Richard Gimer
CAGI
A-10
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2. HEALTH AND WELFARE
Issue
2.1
2.2
2.3
Docket No.
COMMENT;
C032
COS 6
Transcript
Transcript
Transcript
COMMENT;
C024
C028
C030
C034
Transcript
COMMENT;
C029
Transcript
Originator
Consideration should be given to usage conditions
and amount of exposure to the public for different
types of machines in setting the regulation.
D. E. Kipley
Gardner-Denver Company
Richard Gimer
CAGI
Richard Gimer
CAGI
William Heckenkamp
Gardner-Denver Company
Paul Laesch
Sullair Corporation
Benefits to public health and welfare do not
justify the economic impact of the regulation.
R. W. Wiedow
Northern Illinois Gas Company
Hugh I. Myers
Private Citizen
Robert F. Hand
Clark Equipment
American Road Builders Association
William Heckenkamp
Gardner-Denver Company
The regulation will have a beneficial impact
on the public health and welfare.
Thomas F. Scanlan
Grossmont College
David Staples
Environment Health Administration
Washington, D. C.
A-ll
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Issue
2.4
Docket No.
Transcript
Transcript
Transcript
COMMENT;
C024
C034
Originator
Don Gallay
Department of Environmental Control
City of Chicago
Dr. Donna Dickman
Washington Hearing and Speech Society
Alvin Greenwald
Private Citizen
EPA should undertake a more thorough
cost/benefit study.
R. W. Wiedow
Northern Illinois Gas Company
American Road Builders Association
A-12
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3. ECONOMICS
Issue
3.1
3.2
Docket No.
COMMENT;
con
C014
C018
C022
C030
C031
COMMENT;
C016
C028
C030
COS 6
Transcript
Transcript
Transcript
Originator
The portable air compressor regulation is
inflationary.
Bruce J. Smith
Bucyrus-Erie
W. J. Cowan
Barber-Greene Company
Lawrence H. Hodges
J. I. Case
Lawrence H. Hodges
J. I. Case
Robert F. Hand
Clark Equipment
A. J. Cox
CIMA
Smaller manufacturers in the industry will
be those most severely impacted by the regu-
lation.
Richard Ostwald
Gordon Smith and Company
Hugh I. Myers, Jr.
Private Citizen
Robert F. Hand
Clark Equipment
Richard Gimer
CAGI
Robert L. Grievell
Koehring Company
Paul Laesch
Sullair Corporation
Richard Gimer
CAGI
A-13
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Issue
Docket No.
Originator
3.3
Transcript
Transcript
COMMENT;
C006
C009
C010
C022
C027
C030
C031
C033
C035
C036
COS 7
C039
Transcript
George Diehl
Ingersoll -Rand
Richard Ostwald
Gordon Smith and Company
The economic impacts of the useful life pro-
vision were not included in the cost of com-
pliance studies.
J. M. Ombrello
LeRoi Division, Dresser Industries
D. E. Kipley
Gardner-Denver Company
Richard Gimer
CAGI
Lawrence H. Hodges
J. I. Case
George J. Shadtner
Grimmer-Schmidt Corporation
Robert F. Hand
Clark Equipment
A. J. Cox
CIMA
R. D. Harlow
Schramm, Inc.
Caterpillar Tractor Co.
Richard Gimer
CAGI
William S. Price
Worthington Compressors, Inc.
F. A. Dellecave
Ingersoll-Rand
Richard Gimer
CAGI
A-14
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Issue
Docket No.
Originator
3.4
3.5
Transcript
Transcript
Transcript
Transcript
Transcript
Transcript
Transcript
COMMENT;
C006
C027
C036
C040
COMMENT:
COO 6
C009
Robert Harlow
Schramm, Inc.
Richard Ostwald
Gordon Smith and Company
William Heckenkamp
Gardner-Denver Company
William Price
Worthington Compressors, Inc.
Richard Geney
Atlas-Copco
Lawrence H. Hodges
J. I. Case Co.
H. T. Larmore
CIMA
The cost of constructing a test facility at
a manufacturer's plant location is economically
infeasible.
J. M. Ombrello
Le Roi Division, Dresser Industries
George J. Stradtner
Grimmer-Schmidt Corporation
Richard Gimer
CAGI
Bruce J. Smith
Bucyrus Erie
The 16% estimated per unit price increase
is an underestimation of the true cost to com-
ply with the regulation due to the compliance
and enforcement provisions.
J. M. Ombrello
Le Roi Division, Dresser Industries
D. E. Kipley
Gardner-Denver Company
A-15
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Issue
Docket No.
Originator
C010
C016
C022
C027
C031
C032
COS 3
C035
C039
Richard Gimer
CAGI
Richard Ostwald
Gordon Smith and Company
Lawrence H. Hodges
J. I. Case
George J. Stradtner
Grimmer-Schmidt Corp.
A. J. Cox
CIMA
D. E. Kipley
Gardner -Denver
R. D. Harlow
Schramm, Inc.
Caterpillar Tractor Co.
F. A. DelleCave
C040
C036
Transcript
Transcript
Transcript
Transcript
Transcript
Transcript
Ingersoll-Rand
Joseph Q'Neill
Quincy Compressor
Richard Gimer
CAGI
Richard Gimer
CAGI
Robert Harlow
Schramm, Inc.
William Heckenkamp
Gardner-Denver Co.
Lawrence Hodges
J. I. Case Co.
H. T. Larmore
CIMA
Paul Laesch
Sullair Corporation
A-16
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3.7
3.8
3.9
3.10
Docket No.
COMMENT:
C030
Originator
There is no need for a Federal noise regu-
lation for portable air compressors because
marketplace pressures will force production
of quieted machines without a regulation
Robert F. Hand
Clark Equipment
COMMENT; Maintenance of dB(C) levels is costly and
unnecessary
C023
C036
COMMENT;
C022
C030
C023
C036
COMMENT;
Transcript
COMMENT;
C0032
N. J. E. Hartwell
Perkins Engines
Richard Gimer
CAGI
The regulation will have a harmful impact
on foreign trade patterns in the industry
Lawrence H. Hodges
J. I. Case Company
Robert F. Hand
Clark Equipment
N. J. E. Hartwell
Perkins Engines
Richard Gimer
CAGI
.The regulation will have the effect of in-
creasing air compressor rentals, to the
detriment of industry sales volume
Paul Laesch
Sullair Corporation
A board of review should be established
to ensure that manufacturer costs are not
prohibitive
D. E. Kipley
Gardner - Denver
A-17
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Issue Docket No..
3.11 COMMENT:
Transcript
3.12 COMMENT;
C016
3.13 COMMENT:
C002
C015
C016
C027
C032
C033
C037
C039
C040
COS 6
Originator
Large manufacturers can be expected to
stockpile standard machines before the
effective date of the regulation
Paul Laesch
Sullair Corporation
The cost of sound attenuation for a small
manufacturer will be higher per unit than for
a larger company
Richard Ostwald
Gordon Smith and Company
The one-year effective date of the regulation
is an insufficient amount of time and will
cause an increased economic burden on the
manufacturers
Richard Gimer
CAGI
C. M. Copeland
P. K. Lindsay Company
Richard Ostwald
Gordon Smith and Company
George J. Stradtner
Grimmer-Schmidt Corporation
D. E. Kipley
Gardner-Denver Company
Robert Harlow
Schramm, Inc.
W. S. Price
Worthington Compressors, Inc.
F. A. DelleCave
Ingersoll-Rand
Joseph O'Neill
Quincy Compressors
Richard Gimer
CAGI
A-18
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Issue Docket No.
Transcript
Transcript
Transcript
Transcript
Transcript
3.14 COMMENT:
C032
COS 3
C037
C039
C036
Transcript
Transcript
Transcript
Transcript
Transcript
Originator
Richard Gimer
CAGI
Robert Harlow
Schramm, Inc.
William Heckenkamp
Gardner-Denver Company
William Price
Worthington Compressors, Inc.
Paul Laesch
Sullair Corporation
The regulation will force the discontinu-
ation of some manufacturer's compressor
models
D. E. Kipley
Gardner-Denver Company
Robert Harlow
Schramm, Inc.
William Price
Worthington Compressors, Inc.
F. A. DelleCave
Ingersoll-Rand
Richard Gimer
CAGI
Richard Gimer
CAGI
Robert Harlow
Schramm, Inc.
William Heckenkamp
Gardner-Denver Company
William Price
Worthington Compressors, Inc.
Richard Geney
Atlas-Copco
A-19
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Issue Docket No. Originator
3.15 COMMENT; The regulation will cause the non-productive
expenditure of labor and materials.
C028 Hugh I. Myers
Private Citizen
Transcript Richard Geney
Atlas Copco
Transcript John McNally
Caterpillar Tractor Company
A-20
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4. ENFORCEMENT
Docket No.
COMMENT:
4.2
4.3
C018
C036
COMMENT:
C030
COMMENT:
C025
C037
C040
Transcript
Originator
The compliance and enforcement aspects
of the regulation were derived from unrelated
industries and could not realistically or practi-
cally be applied to air compressor manufactur-
ing. The proposal is unreasonable, unjustified,
and impossible to comply with, because of the
more restrictive fashion in which the proposed
rules, which were derived from those promulgated
for control of air pollution from new motor
vehicles and new motor vehicle engines, have
been applied.
Lawrence H. Hodges
J. I. Case
Richard Gimer
CAGI
The regulation manifests a basic distrust of
American industry accompanied by a desire
for EPA to keep its responsibilities to a minimum.
Robert F. Hand
Clark Equipment
Production verification would delay and un-
necessarily burden the manufacturer's distribution
process since distribution in commerce could not
take place until production verification has been
completed.
Walter L. Black
Clark Equipment Co.
William S. Price
Worthington Compressors, Inc.
Joseph O'Neill
Quincy Compressor
George Diehl
Inger soil-Rand
A-21
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Docket No,
COMMENT:
4.5
COS 7
C039
C036
Transcript
Transcript
Transcript
COMMENT:
4.6
COS 7
Transcript
Transcript
Transcript
COMMENT:
Originator
The number of configurations should be mini-
mized and only those parameters for config-
urations that directly affect noise emissions should
be used. The definition of configuration should
be revised, based on cfm engine type and RPM,
with category being defined by cfm only.
William Price
Worthington Compressors, Inc.
F. A. DelleCave
Inger s oil - Rand
Richard Gimer
CAGI
William Price
Worthington Compressors, Inc.
Lawrence H. Hodges
J. I. Case Company
Robert L. Grievell
Koehring Company
Sampling plans are based on high volume
production, and the concept of using a modi-
fication of a well known attribute plan is
inconsistent with small volume production
William Price
Worthington Compressors, Inc.
William Price
Worthington Compressors, Inc.
Lawrence H. Hodges
J. I. Case Co.
Robert L. Grievell
Koehring Company
The Selective Enforcement Auditing strategy
which has a proposed AQL of 6. 5% contradicts
the requirement that every new compressor
conform to the applicable noise emission stand-
ard, since inherent in such a strategy is the
A-22
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Issue
Docket No.
Originator
4.7
C036
COMMENT:
4.8
C025
COMMENT:
4.9
C036
COMMENT:
4.10
C020
COMMENT:
COS 5
C036
assumption that some non-conforming products
will be distributed into commerce.
Richard Gimer
CAG1
The Selective Enforcement Auditing process
places an unnecessary burden on a manufacturer
and all that is required is the "certification"
from the manufacturer that he has tested a
number of units and that they conform to the
regulation.
Walter L. Black
Clark Equipment
The Selective Enforcement Audit should
be invoked only when the Administrator has
cause to believe that a configuration is being
sold in commerce which fails to comply with
the regulation.
Richard Gimer
CAGI
The production verification and Selective
Enforcement Auditing Scheme will provide
a high assurance of product conformity and
further that a major savings in administrative
costs for both the manufacturer and EPA should
be realized because this particular enforcement
scheme has definite benefits over the enforcement
scheme employed in certification of automobiles
pursuant to the Clean Air Act of 1970.
Mary Ann Zimmerman
Cummins Engine
The Administrator's discretion to refuse to
grant a hearing in situations where Section
ll(d) orders are issued is a matter of concern.
Caterpillar Tractor Company
Richard Gimer
CAGI
A-23
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Issue
Docket No.
Originiator1
4.11
4.12
4.13
C037
COMMENT;
C035
C036
COMMENT:
4.14
C013
C035
C036
C037
COMMENT;
C032
C013
C030
C036
COMMENT:
William S. Price
Worthington Compressors, Inc.
The limitation of the right to counsel in the
regulation should be stricken.
Caterpillar Tractor Co.
Richard Gimer
CAGI
The need and validity of EPA to make broad
inspections and have the right to inspect and
photograph all and any literature and test records
is questionable. Such provisions extend far
beyond the authority conveyed to EPA and far in
excess of any Agency needs.
Robert A. Heath
Walker Manufacturing
Caterpillar Tractor Co.
Richard Gimer
CAGI
William S. Price
Worthington Compressor, Inc.
The information recording and reporting
requirements are burdensome and costly.
D. E.,Kipley
Gardner-Denver Co.
Robert A. Heath
Walker Manufacturing
Robert F. Hand
Clark Equipment
Richard Gimer
CAGI
The proposed regulation in some instances
requires the repetitive submission of infor-
mation.
A-24
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Issue
Docket No.
Originator
4.15
4.16
C022
COMMENT;
C036
COMMENT:
4.17
C013
COMMENT:
C010
C015
C016
C019
C022
C027
C030
Lawrence H. Hodges
J. I. Case Co.
Cease to distrubute orders are beyond the
statute and should be modified.
Richard Gimer
CAGI
The statement contained in the proposed
regulation "all costs associated with recall
and remedy of non-complying compressors
shall be borne by the manufacturer" could be
interpreted very broadly.
Robert A. Heath
Walker Manufacturing
The costs of the administrative enforcement
provisions would be significant because of the
large number of products that would be required
to be tested as a result of the production veri-
fication and audit tests required, the record
keeping and recording requirements and the
costs of constructing added test facilities to
accomplish all the required testing.
Richard Gimer
CAGI
C. M. Copeland
P. K. Lindsay Co.
Richard Ostwald
Gordon Smith and Co.
R. D. Harlow
Schramm, Inc.
Lawrence H. Hodges
J. I. Case Co.
George J. Stradtner
Grimmer-Schmidt Co.
Robert F. Hand
Clark Equipment
A-25
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Issue
Docket No.
4.18
C031
COS 3
C035
COS 6
A. J. Cox
CIMA
R. D. Harlow
Schramm, Inc.
Caterpillar Tractor Co.
Richard Gimer
Originator
COS 9
C040
Transcript
Transcript
Transcript
Transcript
Transcript
COMMENT;
C013
C002
C016
C018
C025
CAGI
F. A. DelleCave
Ingersoll-Rand
Joseph O'Neill
Quincy Compressor
H. T. Larmore
CIMA
Richard Gimer
CAGI
Robert Harlow
Schramm, Inc.
Willaim Heckenkamp
Gar dner- Denver
Lawrence H. Hodges
J. I. Case Co.
The warranty required by §204.58-1 is a
useful life performance warranty.
Robert A. Heath
Walker Manufacturing
Richard Gimer
CAGI
Richard Ostwald
Gordon Smith and Co.
Lawrence H. Hodges
J. I. Case Co.
Walter L. Black
Clark Equipment Co.
A-26
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Issue
Docket No,
Originator
4.19
4.20
C036
C030
C031
COS 7
COS 5
COMMENT:
C022
COMMENT:
4.21
C030
COS 5
COMMENT:
4.22
C036
COMMENT:
C031
Richard Gimer
CAGI
Robert F. Hand
Clark Equiplment
A. J, Cox
CIMA
W. S. Price
Worthington Compressors, Inc.
Caterpillar Tractor Co.
Which "manufacturer" must issue the noise
emission warranty requires clarification.
Lawrence H. Hodges
J. I. Case Co.
That which constitutes tampering should be
defined, and whether or not the use of after -
market parts (parts not manufactured or
authorized by the original equipment manu-
facturer) would constitute tampering should
be clarified.
Robert F. Hand
Clark Equipment
Caterpillar Tractor Co.
In the tampering requirements submissions of
information 90 days before introduction into
commerce of the compressor represents an
excessively long time period for the manufac-
turer.
Richard Gimer
CAGI
The requirements for lists of noise control
devices, performance specifications for such
device, and acts which constitute tampering are
unfair, voluminous, and unduly costly.
A. J. Cox
CIMA
A-27
-------
Issue Docket No. Originator
C037 William S. Price
Worthington Compressors, Inc.
COS 6 Richard Gimer
CAGI
A-28
-------
5. MISCELLANEOUS
Issue Docket No. Originator
5.1 COMMENT: Noise regulations directed at the end prod-
uct are preferable to those for individual
component parts.
C020 Mary Ann Zimmerman
Cummins Engines
5.2 COMMENT; The regulation should be rewritten to improve
the prose relating to numerical descriptors of
noise.
C021 Dr. Robert W. Young
Acoustical Society of America
5. 3 COMMENT; The definition of a portable air compressor
should be clarified so as to exclude any prod-
ucts not intended to be subject to the regu-
lation.
C026 M. E. Rumbaugh, Jr.
Schwitzer Engineered Components
A-29
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RESPONSE 10 ISSUES
The EPA has carefully considered all of the comments received re-
garding the proposed noise emission regulation for portable air compres-
sors. A discussion of these comments with the Agency's response thereto
follows:
1. Technology
1.1, 1.2 One commenter stated that the 76 dBA limit does not represent
currently available technology.
The "Background Document for Proposed Portable Air Compressor Noise
Emission Regulations" presents data from several compressors that emit noise
levels of 76 dBA and lower at 7 meters. Technological availability is,
EPA believes, adequately met when mass produced commercially available
products are in commerce today which produce noise at or below the standard.
1.3 Several commenters asserted that data relating to degradation of
noise emission characteristics are insufficient to predict degradation
patterns for air compressors.
The Agency pursued this issue by soliciting industry comment and
supportive data regarding the escalation of compressor noise that would
accrue during compressor usage. Responses to the solicitation indicated
that data were not available at this time, since in the past there was
not a need for the assessment.
A-30
-------
Accordingly EPA has undertaken studies to develop these data.
Industry representatives have also agreed to begin to collect and to make
available to the Agency such noise emission degradation data so that
proper analysis and decisions regarding useful life standards, including
degradation effects, can be made at a later date.
1.4, 1.5 Several industry commenters stated that fuel consumption can be
expected to increase as a result of the regulation, while another industry
commenter stated that fuel consumption could be expected to remain the
same or actually decrease.
As has been indicated, there is substantial disagreement within
the industry itself regarding the impact of the regulation on fuel con-
sumption. From a technical standpoint, those commenters contending that
fuel consumption may increase indicate that it will be due primarily
to an increase in static pressure within the portable air compressor
enclosure due to added noise control components. This, in turn, would
cause increased fan loading and a concomitant increase in fuel consump-
tion on the order of 3 - 8 percent. Another industry commenter stated
that there would be no fuel consumption increase that would result from
the quieting efforts. That commenter indicated that the fuel savings
derived from the use of more efficient fans would balance increased fuel
consumption resulting from increased fan loading.
A-31
-------
The Agency, in the course of its technology studies, attempted to
assess fuel usage differences between standard and quieted compressors of
the same model. All attempts proved futile because changes in fuel usage
were within the manufacturing tolerance variances and thus there was no
apparent significant effect.
1.6 Several commenters stated that the quieting technology is not the
same for all sizes and configurations of air compressors.
The Agency assessed the quieting technology applied to several model?
of compressors on the market «>day. The assessment revealed that, while
the large, high air flow capacity compressors generally required greater
silencing effort than did the smaller, lower air flow capacity units,
similar techniques were applied to achieve the silencing. Accordingly,
the effective date of the regulation has been modified to provide manu-
facturers with a longer lead time to integrate noise control features into
the design and manufacture of larger portable air compressors.
1.7, 1.11 Several commenters were concerned about the^ problems they may
encounter regarding availability of component parts, especially quieter
engines, necessary to manufacture portable air compressors which will
comply with the standard.
The withdrawal from the market of certain engines used by portable
air compressor manufacturers because of other reasons than noise control
became known during the comment period. In assessing the impact of this
action, the Agency questioned the portable air compressor manufacturers
about the problems they anticipated as a result of this action by engine
manufacturers. All who responded to the questions indicated that the
action would have a dramatic adverse impact on the engineering design
A-32
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and manufacturing time required to develop compressors meeting the standard
and further indicated that component delivery problems could be handled
if the effective date of the regulation were extended. The Agency con-
sidered all aspects of this problem and, accordingly, extended the time
for compliance with the regulation since the results of studies showed
that such extension would not significantly compromise health and welfare
benefits to be derived from the regulation. It is the Agency's belief
that the additional time allotted affords the lead time stipulated by the
manufacturers to allow them to overcome any delivery problems they are
likely to encounter regarding component parts.
1.8 Two commenters stated that "band aid" measures for controlling noise
emissions are more expensive than integrated design changes.
The Agency recognized this, and accordingly, solicited comments
from portable air compressor manufacturers as to the time it would take
to make and implement the necessary design changes to produce quiet
machines. The effective date of the regulation is based to a substan-
tial degree on the data supplied by the respondent manufacturers. It
is the Agency's opinion that the time span before the regulation becomes
effective provides manufacturers with the requisite lead time to accom-
plish the necessary design changes, if they so desire, to preclude the
"band aid" approach.
1.9, 1.18 Two commenters responded to the solicitation, in the preamble
of the proposed regulation, for views as to whether a standard should be
imposed on portable air compressors measured in C-weighted sound pressure
level.
A-33
-------
The intent of the solicitation was to elicit information in regard to
imposing a C-weighted noise emission standard to guard against design
practice that would shift the major spectral components of portable air
compressor noise to low frequencies discriminated against by the A-
weighted sound pressure, at the possible expense of escalated low fre-
quency noise, which in turn could cause vibration problems in structures
located in proximity.to construction sites.
At the time the proposed regulation was developed, the Agency had
limited data to support a C-weighting sound pressure level standard. The
public solicitation for data in this regard has provided little information
and no new data to show the need for a dBC standard. Accordingly, only
a dBA standard is being promulgated.
1.10 One commenter suggested that devices be installed that would shut-
down a compressor if the access doors were opened.
The Agency considered the validity and practicality of such a
requirement and decided not to require the installation of such devices
for the following reasons: 1) One use of portable air compressors is to
supply breathing air to workmen involved in activities underground where
the naturally occurring air supply is minimal. An inadvertent shutdown
of the compressor in this situation could have catastrophic consequences.
2) Users could easily circumvent automatic shutdown devices if such devices
proved to be an annoyance or otherwise hindered the user's normal operating
procedures. However, the Agency recognizes that the doors of portable air
compressors may be an element of design incorporated into the product to
achieve compliance with the regulation. Accordingly, and as stated in
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the tampering section of the regulation, the removal or rendering in-
operative, for purposes other than maintenance, repair or replacement,
of such a device is prohibited.
1.12 Several commenters responded to the solicitation in the Pre-
amble of the Notice of Proposed Rulemaking, for comments in regard to
the proposed measurement methodology and/or the advisability of express-
ing the portable air compressor standard in terms of sound power rather
than average sound pressure level.
During the development of the proposed regulation, EPA carefully
considered the various measurement methodologies and sound descriptions
suitable for the assessment and characterization of portable air com-
pressor noise. As a result of these studies, it is EPA's opinion that the
methodology as proposed will provide data to accurately characterize
portable air compressor noise with the simplicity that is requisite to
facilitate product verification at the manufacturer's plant and enforce-
ment in the field. The following private and public proclamation by
portable air compressor manufacturers is significant in this regard:
"Members of CAGI have carefully studied the measurement
methodology and at the January 19, 1975, meeting of the Compressed
Air and Gas Institute, Portable Air Compressor Section,
it was resolved the physical measurement procedures contained
in the proposed EPA measurement methodology be accepted
by CAGI."
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While the Agency has opted for a measurement methodology with which
industry is most familiar at this time, and which supports its compliance
requirements, and has opted to use A-weighted sound pressure level as the
descriptor of portable air compressor noise, it recognizes that situations
may exist or arise where other methodologies and descriptors may be just
as appropriate and, for that matter, have more utilitarian use. Such
instances or situations may exist within a particular product industry
when one wishes to describe the energy output of devices for noise emis-
sion diagnostic evaluation and for comparing the noise emission of devices
which are similar in size and kind. Accordingly, the Agency encourages in-
dustry to proceed toward standardization of methods to determine sound
power with attendant sound energy descriptors, as it is endeavoring to do
at this time. The Agency has carefully reviewed two recent efforts toward
standardization developed by the National Bureau of Standards (NBS) and
Technical Committee £3 of the International Organization for Standardization
(ISO) and it is EPA's opinion that these test methodologies are feasible and
viable, and EPA would recommend their use for the determination of portable
air compressor sound power in situations requiring such assessment.
1.13 One commenter stated that the test specification for a fifth micro-
phone above the compressor should be reconsidered.
The Agency included an overhead microphone location to guard against
compressor design that would direct major sound energy upwards which could
be of significance to persons working or residing in high rise buildings
adjacent to construction sites and/or where portable air compressors are
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located below ground level and the noise impacts on those above the equip-
ment affected. The Agency reconsidered the need for the overhead micro-
phone position and concluded that its imposition is indeed requisite to
control upward radiated compressor noise, for without it there is no
practicable way to assure that upward radiated noise will not exceed the
stipulated level.
1.17 Several commenters stated that, in order to comply with the reg-
ulation, manufacturers must design for levels well below the standard.
In developing the regulation, the Agency recognized that a class
of compressors, for that matter a single compressor, may emit noise
levels that vary by as much as + 2 dBA as the result of manufacturing
tolerances. Accordingly, the Agency does not recognize the need for
manufacturers to design "well below" the standard to ensure compliance
with the regulation.
1.19 Several commenters stated that the EPA measurement methodology
is not suitable for in-use testing at a construction site, with reasons
such as anticipated difficulty in measuring 7 meters above a com-
pressor, difficulty in teaching noise inspectors to perform noise level
averaging on an energy basis, and problems with high ambient noise as the
rationale for the statement.
In the development of the proposed measurement methodology, it
was the Agency's intent to arrive at a test method that could facilitate
both noise emission testing in the controlled environment at the manu-
facturer's test site as well as noise emission level assessment in the
uncontrolled environment of construction sites. What has evolved is a
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simple, practicable test method which, while not patently ideal for both
test environments, provides manufacturers of portable air compressors a
method to assure compliance with the noise emission standard. It also
provides State and local noise inspectors with a methodology or, at a
minimum, a methodology base on which to build or modify as local conditions
may dictate, for their development of equivalent test procedures for in-
use noise emission evaluation.
1.20 One commenter stated that no machine larger than 1200 cfm was
tested as the basis for the EPA background document.
While it is true that the Agency did not conduct tests on portable
air compressors larger than 1200 cfm, test data on machines with air
flow capacities up to 2000 cfm were made avilable to the Agency and are
in fact included in a listing presented in Table 7-5 (c) of the "Back-
ground Document for Proposed Portable Air Compressor Noise Emission
Regulations."
1.21 One commenter stated that a conflict between noise suppression
technology and safety considerations may exist regarding the flame re-
tardant properties of acoustical insulation laggings.
EPA interprets this comment to mean that acoustical materials that
may be employed within compressor enclosures might tend to support
combustion. In addition, those materials that might be employed would
act as a sponge to soak up fuel and oil and thus create a potentially
hazardous condition should the oil/fuel flash point temperature be
exceeded. As most acoustical materials may be chemically treated with a
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flame retardant'to prevent combustion, and it is common practice to
encapsulate acoustical foams and fiberglass in mylar and other thin filmed
impervious protective coverings to preclude absorption of liquids, EPA
is of the opinion that no conflict exists between safety considerations
and noise suppression technology.
1.22 One commenter responded to the preamble solicitation for comment
on whether the regulation should address portable air compressor pure
tones.
Currently, major pure tone spectral components generated by today's
portable air compressors occur at low frequencies, less than 500 hertz,
and are not -particularly annoying as the frequencies are below the range
of acute ear sensitivity. However, the Agency recognizes that as port-
able air compressor designs change, so too may the spectral character of
the pure tone generating components to cause annoying pure tones. Accord-
ingly, the Agency will continue to address the potential problems of pure
tone noise with respect to portable air compressors, and it solicits on a
continuing basis such information from concerned parties. Should evidence
in the future show this to be a significant problem, the Agency is pre-
pared to propose such control measures as may be necessary.
1.23 Several commenters felt that some tolerance on the standard should
be allowed on field tests to account for environmental and instrumenta-
tion variances likely to occur when portable air compressors are tested in
environments different from the controlled environment of the manu-
facturer's facility.
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The Agency recognizes that, due to environmental and instrumentation
differences, noise emission data measured at State and local test sites may
differ from that measured during SEA and PV testing, and the Agency will take
this into account when reviewing test data.
2. Health and Welfare
2.1 Several commenters stated that in setting the regulation, considera-
tion should be given to usage conditions and amount of exposure to the
public for different types of machines.
In developing the regulation, the Agency considered the usage con-
ditions and amount of exposure to the public for different types of
machines. In the analysis, the Agency employed portable air compressor
usage factors and noise levels to investigate health and welfare benefits
derived from the regulation of the total population of portable air com-
pressors. A second analysis was conducted for the population of com-
pressors split into units typically used in urban areas and those typi-
cally used in rural areas. The studies considered the usage of compres-
sors in five phases of construction: domestic housing, non-residential,
industrial, and public work construction. The "Background Document for
Portable Air Compressor Noise Emission Regulations" presents further
details of the analysis.
2.2, 2.3 Several commenters stated that the benefits to public health and
welfare do not justify the economic impact of the regulation.
It must be kept in mind that society is now paying billions of
dollars for noise pollution associated with lost productivity, higher
medical bills and health insurance premiums, payments in successful noise
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offense litigation and assessment of property value in high noise ex-
posure areas without accruing any direct benefit for such payments. Im-
plementation of the Noise Control Act of 1972 will accomplish a shift in
the economic burden from the impacted population to the users of the pro-
ducts and their customers and hence will provide society with direct
benefits in the form of quieter products and a quieter environment.
It is estimated that over 27 million people are exposed to con-
struction site noise levels that jeopardize their health and welfare.
Since construction site noise is typically comprised of contributions
from more than twenty different types of construction equipment, regu-
lation of the majority of the pieces of equipment will be required to
appreciably and effectively reduce this type of noise. The portable air
compressor has been identified as the first piece of construction equip-
ment requiring noise emission control to foster, in the long term, less
construction site noise. While portable air compressors may not provide
the highest sound level at construction sites, they do contribute
significantly to community noise exposure. Air compressors rank with
dump trucks and concrete trucks in producing the highest sound energy
per day. The noise emission regulation for portable air compressors is
requisite to protect the health and welfare of the American public.
Studies performed in accordance with the requirements of the Noise
Control Act of 1972 indicate that compliance with the regulation will
reduce the impact upon people from construction site noise by 14.7 percent
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with an estimated attendant 12.3 percent increase in the list price of
portable air compressors. Upon regulation of noise emissions from dump
trucks and concrete trucks, a reduction in total impact by approximately
45 percent is anticipated when the current population of compressors and
trucks is replaced by quiet units. Further reduction in total impact is
contingent upon effective noise emission regulations of other construction
equipment. Considering the health and welfare benefit obtained from the
regulation, the Agency believes that the added cost of compressors is a
productive expenditure.
2.4 Several commenters suggested that EPA undertake a more thorough cost/
benefit study.
The Agency conducted additional economic impact and health and wel-
fare impact analyses employing data and information made available to it
as the result of the written comment period and public hearings regarding
the proposed regulation. The Agency also solicited information from
portable air compressor manufacturers regarding the lead time necessary to
comply with various standard levels. The regulation being promulgated is
based, in part, on the results of these analyses.
3. Economics
3.1 Several commenters indicated that they felt that the Portable Air
Compressor Regulation is inflationary.
The EPA, in promulgating a noise source emission regulation for
newly manufactured products, is directed by the Noise Control Act of 1972
to consider the cost of compliance, best available technology, and impact
on the public health and welfare. The Agency has carefully weighed
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the potential adverse economic impacts associated with the promulgation
of the regulation and compared them to the benefits that would accrue to
the population affected by the reduction in noise emitted by portable air
compressors. The conclusion is that the 12.3 percent list price increase
is cost effective in terms of the benefits derived. The health and wel-
fare benefits of the proposed regulations have been discussed previously
in paragraph 2.2 and 2.3.
3.2, 3.12 Several commenters indicated that they felt that the smaller
manufacturers will be more severely impacted and their costs per unit will
be higher than those for larger portable air compressor manufacturers.
The Environmental Protection Agency pursued this issue through
visits and communications with large, medium, and small portable air
compressor manufacturers in an effort to determine the validity of the
comment. As a result of the Agency's investigations and data surfaced in
pursuit of the issue, it became apparent that the effective date of the
regulation was the single major factor controlling the degree of economic
impact on the portable air compressor industry of the proposed standard,
particularly on the smaller manufacturer. According to the data, a
smaller manufacturer faced a greater potential for serious economic
impact from the 12-month effective date because of limited resources
and manpower to accomplish the requisite redesign of his product line
to achieve product compliance in a timely fashion. As such, the
smaller manufacturer could be constrained by the regulation from intro-
ducing his units into commerce and thereby accrue a severe economic
impact. Accordingly, after determining that a limited extension of the
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effective date of the regulation would not severely impact the health and
welfare benefits to be derived, the Agency has extended the effective date
of the regulation to 24 months for compressors with air-flow capacity less
than or equal to 250 cfm, and 30 months for compressors with air-flow
capacity greater than 250 cfm. It is the Agency's belief that this
extension allows ade.quate .lead time for an orderly readjustment by all
manufacturers to preclude potential economic hardships associated with
time constraints imposed by the proposed effective date.
3.3 Many commenters indicated that the economic impacts of the useful life
provision contained in the proposed regulation were not included in the
cost of compliance studies that were undertaken.
The Agency reviewed the useful life provision contained-in the
proposed regulation in light of the comments made in the various dockets.
The Agency has elected not to specify at this time a specific require-
ment "for portable air compressor useful life noise emission standard. The
Agency has chosen, however, to defer a useful life provision in the
Portable Air Compressor Regulation until further studies regarding the
degradation of noise emissions of portable air compressors and the as-
sociated costs of compliance have been completed and assessed against the
health and welfare benefits which could result from the imposition of
such a useful life standard.
3.4 Several commenters stated that the cost of constructing a test
facility at a manufacturer's location is economically infeasible.
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The Agency does not feel that the required measurement/testing
procedure will necessitate the construction of elaborate, expensive test
facilities for portable air compressor manufacturers. Accordingly, the
test procedure, including the description of the test site, as it appeared
in the proposed regulation stands as the EPA test procedure which will be
utilized to determine compliance with the standard. However, as now
stated in the regulation, alternate test procedures which are approved by
EPA by virtue of demonstrated correlation with the prescribed procedure,
may be employed by the manufacturers.
3.5 Many commenters stated that the estimated 16 percent per unit price
increase underestimates the true cost to comply with the regulation due
to the enforcement provisions.
The 16 percent preliminary estimate of list price increase included
in the preamble to the proposed regulation did not include costs for
enforcement and useful life provisions. In the final analysis performed
by the Agency, the deferment of a useful life standard and further con-
sideration of the enforcement scenario led to the following estimated
list price increases for newly manufactured portable air compressors:
1. 11.2 percent for compressors with rated flow capacity less
than or equal to 250 cfm.
2. 13.0 percent for compressors with rated flow capacity greater
than 250 cfm.
3. An additional estimated 0.4 percent list price increase
may accrue through the costs of the revised enforcement
scenario of the regulation.
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3.6 One commenter indicated that there was no need for Federal regula-
tion of portable air compressors because marketplace pressures will force
the production of quieted machines without a regulation.
This assertion has, in fact, not been demonstrated. Although there
are models of compressors that are quieted, the noise emissions of the
compressor population as a whole have not been reduced to a level that is
protective of the public health and welfare. Additionally, there are no
indications that- the industry as a whole was moving in the direction of
quieting the compressor fleet to levels that are considered to be pro-
tective of the public health and welfare.
3.8 Several commenters indicated that the regulation will have a
harmful impact on the foreign trade patterns in the industry.
The Agency assessed the impact of the regulation on trade patterns.
The analysis showed that there would be no change in import patterns
and no material impact on the balance of trade. Since the Noise Control
Act specifically exempts units manufactured solely for export there will
be no changes in portable air compressor export patterns resulting from
this rulemaking.
3.9 One manufacturer indicated that the regulation will have the
effect of increasing air compressor rentals, to the detriment of
industry sales volume.
The Agency reviewed this issue during its background study to assess
the impact of the proposed regulation. Today without Federal regulation,
approximately 50 percent of portable air compressor unit shipments reach the end
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user through rental or rental/purchase agreements. The reason for this
rests with cost effectiveness; that is, in many instances, it is probably
more economical to rent a unit for a specific job taking place in a
finite period of time than to tie up capital in a unit not receiving full
usage.
While it is recognized that rental usage could increase, by virtue
of its apparent economic advantage, the Agency has no quantitative data
to show any increase solely due to imposition of the regulation. The
Agency has, however, estimated i_hat imposition of the regulation would
cause no more than a 4.3 percent decrease in total unit sales.
3.10 One manufacturer suggested that a board of review be established to
ensure that manufacturers' costs are not excessive.
The Noise Control Act of 1972 does not contain any provision for
the establishment of such a panel. The EPA has, however, made every
attempt to estimate the economic impact on the portable air compressor
manufacturing industry. The regulation does not in EPA's judgment impose
any unreasonable or excessive costs on the industry.
3.11 One commenter stated that large manufacturers can be expected to
stockpile standard machines before the effective date of the regulation.
The Noise Control Act prohibits distribution in commerce of
products manufactured after the effective date which do not meet the
standard. Thus, under the Act, Congress intended that products manu-
factured earlier shall be exempt and may be distributed in commerce at
any time even if they do not meet the standards. The nature of portable
air compressor manufacturing and marketing is such that distributors are
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expected to have several pre-regulation compressors available for sale
at the time the regulation becomes effective, and this probability was
considered in the assessment of health and welfare impact of the
regulation.
The analysis of this issue focused on industry production capacity,
i.e., basic ability to stockpile. On an average across the industry
current production capacity is such that limited stockpiling is possible,
if the assumption is made that the compressor market will remain rela-
tively stable until the regulation is effective. Combined in this analysis
is the historical flexibility of the portable air compressor industry in
responding to market demand fluctuations. Consideration of these factors
and the general expense of stockpiling inventory led to the Agency con-
clusion that the stockpiling possibility will be evenly assessed by in-
dustry and that individual manufacturers will be able to avert market
disruptions in that event.
3.13 Several manufacturers stated that the 1-year effective date of
the regulation is an insufficient amount of time and will cause an in-
creased economic burden on the industry.
In further study and discussions with the various manufacturers,
the Agency was able to better estimate the time dependency of successful
compressor redesign. The presence in the industry of several manufacturers
who have little or no quieting experience, and additional information
which showed that quieting is more difficult to achieve in the larger
compressors, led us to extend the time for compliance. In addition, our
further study revealed that many of the costs for redesign are fixed, and
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lengthening of the time for compliance should allow for more orderly
adjustment in the industry.
3.14 Various industry members commented that the regulation will force
the discontinuation of some manufacturers' compressor models.
This issue was considered in further economic impact studies follow-
ing the public comment period. Obviously, for those manufacturers who
now market both standard and quiet compressors in identical cfm cate-
gories, it would be implied that they would discontinue the so-called
standard model as a result of the regulation. The more critical poss-
ibility is the unforeseen, forced temporary or permanent discontinua-
tion of a compressor model because of added expense to quiet in the
time frame specified, or because of assembly delays resulting from
component part deliveries approaching or exceeding the effective date
of the regulation. Analysis of the problem included this possibility
and the Agency concluded that the extended time now allowed for compli-
ance with the standard as opposed to the time frame originally proposed
will allow manufacturers to effectively compensate for design and
assembly problems of this nature. However, some manufacturers now market
marginally profitable models, and the possibility of discontinuation
of these models because of this regulation exists. In instances of
discontinuance of marginally profitable models, it is the Agency's
position that this is not necessarily a detrimental effect of the regu-
lation; the Agency has no specific information indicating the likelihood
of this occurring.
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3.15 Three commenters stated that the regulation will cause the non-
productive expenditure of labor and materials.
During the development of the regulation, the Agency conducted
studies to arrive at a noise emission standard requisite to protect the
public health and welfare with an adequate margin of safety, taking into
account the magnitude and conditions of use of portable air compressors,
the degree of noise reduction achievable through the application of best
available technology, and the cost of compliance. The standard that has
evolved, is, in the Agency's opinion, technically feasible, non-
inflationary, and protective of the public health and welfare. Accord-
ingly, the regulation will cause productive expenditure of labor and
materials.
4. Enforcement
4.1 Two of the commenters felt the compliance and enforcement aspects of
the proposed portable air compressor regulation, which is derived from
air pollution control regulations, could not realistically or practically
be applied to air compressor manufacturing industry.
The regulation being promulgated contains production verification
requirements and selective enforcement auditing requirements. The prod-
uction verification scheme differs from certification under the Clean Air
Act. No extensive endurance testing is required by production verifica-
tion, and the manufacturer is not precluded from selling his product until
he has accomplished the requirements of the production verification
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process. In essence, the Clean Air Act certification process is merely
used to allow the manufacturer to demonstrate that he has the requisite
technology in hand to produce conforming products. The production veri-
fication process is based on the assumption that the manufacturer has
the technology available to quiet compressors and must demonstrate that
he is able to apply that technology in practice to produce compressors
complying with the standard.
The selective enforcement auditing scheme is very similar to that
which EPA has proposed for use under the Clean Air Act to verify compliance
of production vehicles with the standard. It is a noncontinuous scheme,
wherein samples of products are tested to determine whether they conform
to the standards. Such a scheme is equally applicable to the testing of
completed motor vehicles as it is to testing completed portable air com-
pressors. It should be kept in mind that this testing will only be done
on the specific request of the Agency.
4.2 One commenter felt the regulation manifested a basic distrust of
American industry accompanied by a desire for EPA to keep its responsi-
bilities to a minimum.
The basic EPA enforcement strategy under the Noise Control Act of
1972 places a major share of the responsibility on the manufacturer for
testing to determine compliance of new portable air compressors with
the regulation and emission standards. This does not relieve EPA of
its responsibilities but merely allows a manufacturer to have his
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personnel in control of many aspects of the compliance program, thereby
minimizing the burden of this regulation on his business. Such manu-
facturer responsibility and control results from the fact that EPA has
faith in the integrity of manufacturers to comply with this regulation.
EPA, however, does reserve the right to verify that the manufacturer is in
fact complying with the regulation. It is for this reason that EPA pro-
vides for monitoring by EPA personnel of tests performed by the manu-
facturer and other manufacturer actions taken in compliance with this
regulation. The final purpose of such monitoring is to assure the
Administrator that the information he is receiving is accurate to enable
him to make the proper determination that compressors being distributed
in commerce by a manufacturer are, in fact, in compliance with this
regulation.
4.3 Some manufacturers commented that production verification would
delay and unnecessarily burden the manufacturer's distribution process
since distribution in commerce could not take place until production
verification has been completed.
The regulation has been modified to permit manufacturers to dis-
tribute compressors in commerce as soon as production begins. The
requirement still remains that the manufacturer must test certain models
of his early production units, which for the most part are the loudest
configuration of a category. However this testing must now take place,
as soon as weather conditions permit, within a 45-day grace period,
during which production verification is waived. The 45-day period
is designed to accommodate a manufacturer's transportation needs
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and to accommodate poor weather conditions. In addition, the requirement
that the manufacturer provide a 10-day notice of his intent to test has
been removed.
4.4 Some manufacturers suggested that the number of configurations be
minimized and only those parameters for configurations that directly
affect noise emissions be used. One manufacturer endorsed a revision
of the definition of configuration to cfm, engine type and rpm, with
category being defined by cfm only.
Although the definition of category has remained the same and is
based on those elements which most directly affect noise, the definition of
configuration has been changed, with the defining parameters significantly
reduced. The Agency has calculated, based on available information, the
total number of categories that would require testing based on production
verification if carried out in accordance with this regulation, and has
found that it results in a nominal number of products requiring testing.
Any further reduction in the criteria used to define category would not be
warranted, on the basis of reducing test burden, since the number of units
requiring testing is now realistic.
4.5 Some manufacturers commented that the sampling plans are based on
high volume production and that the concept of using a modification of a
well-known attribute plan is inconsistent with small volume production.
As a result of such comments, the sampling plans contained in the
proposed regulation have been modified to provide for situations in which
production volume is small. Additionally, the revised sampling plan
significantly reduces the number of products requiring testing.
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4.6 One commenter suggested that the selective enforcement auditing
(SEA) strategy, which had a proposed acceptable quality level (AQL) of
6.5 percent contradicts the requirement that every new compressor con-
form to the applicable noise emission standard, since inherent in such
a strategy is the assumption that some nonconforming products will be
distributed in commerce.
The regulation being promulgated now contains an AQL of 10 percent
and, although this AQL may result in some nonconforming products being
distributed in commerce, the basic requirements still remain that a manu-
facturer is prohibited from distributing into commerce any products
which do not conform with the standard. The basic intent is that all
products being distributed in commerce must conform to the standard.
Any product which is tested and which is known not to conform to the
standard may not be distributed into commerce until the nonconformity is
remedied. Furthermore, every compressor is warranted to conform to the
standards at the time of sale. It is merely the intent of EPA not to
take enforcement action which addresses the aggregate of the products or
the process by which they are produced until the process average as
determined by SEA testing exceeds the AQL of 10 percent. That is not to
say the EPA permits the distribution in commerce of products that exceed
the standard, but only that no enforcement action will be taken on the
aggregate by EPA unless an AQL of 10 percent is exceeded. A batch which
meets the AQL of 10 percent is considered to indicate compliance by
virtually 100 percent of the compressor population. The 10 percent allow-
ance provides for test variability and random human error.
4.7 One commenter suggested that the SEA process placed an unnecessary
Surden on a manufacturer and all that was required is the "certification"
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from the manufacturer that he has tested a number of units and that they
conform to the regulation.
The selective enforcement auditing scheme is not a continuing re-
quirement. Testing is performed at the request of the Administrator.
The testing burdens will exist only when deemed necessary by the Admin-
istrator for purposes of gathering information in order to make a deter-
mination regarding the conformity of products being distributed in com-
merce by a particular manufacturer.
The issuance of a test request may not be necessary where the manu-
facturer can demonstrate through his own test data on production units,
using a sampling plan similar to or better than the promulgated plan, that
his process average is below the AQL of 10 percent. This amounts to the
"certification" procedure suggested by the commenter.
4.8 One commenter suggested that SEA should be invoked only when the
Administrator had cause to believe a configuration is being sold in com-
merce which fails to comply with the regulation.
Although EPA agrees with the spirit of that comment, the Administra-
tor prefers to maintain the discretion that Congress intended by not
having placed any such limitations on his testing authority. It is the
EPA's intent, however, that such test requests be issued when the need
arises and that such need be clearly demonstrated.
4.9 One commenter felt that production verification and the selective
enforcement auditing scheme would provide a high assurance of product con-
formity and further, that a major savings in administrative costs for both
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the manufacturer and EPA should be realized because this particular en-
forcement scheme has definite benefits over the enforcement scheme
employed in certification of automobiles pursuant to the Clean Air Act
of 1970.
4.10 Several commenters were concerned with the Administrator's discre-
tion to refuse to grant a hearing in situations where Section 11(d)
orders were issued.
The regulation has been modified to provide that in situations
where Section 11(d) orders are issued, notification and an opportunity
for a hearing are afforded.
4.11 Several commenters criticized the attempt by the regulation to
limit the right of counsel and recommended that such limitation be
stricken from the regulation.
As a result of those comments, portions of the regulation which
would, in fact, limit the right of counsel have been deleted.
4.12 Several commenters questioned the need and the validity of EPA to
make broad inspections and to have the right to inspect and photograph
all literature and test records. The commenters indicated that such
provisions extend far beyond the authority conveyed to EPA and far in
excess of any Agency needs.
The regulation has been modified to limit inspections and acquisi-
tion of data to information necessary for the Administrator to make a
determination that the manufacturer is distributing conforming products
in commerce. The authority of EPA personnel is limited to examining
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records of tests conducted on production verification products or pro-
ducts tested pursuant to SEA, inspecting areas where testing is conducted
and where products are stored prior to testing, and inspecting areas of
the assembly plant where the products are being assembled. EPA has no
interest in forced entry into developmental laboratory areas. However,
where such areas are part of the test site used for compliance testing,
it is the intent of the regulation to permit access to such areas regard-
less of the fact that developmental labs or test sites are near by. If
a manufacturer wishes to preclude EPA Enforcement Officers from visiting
or inspecting their development testing or laboratory areas, they must
be separated from areas where compliance testing is performed.
4.13 Several commenters stated that the information recording and re-
porting requirements are burdensome and costly.
The regulation has been revised so that information needed to
describe a product may be satisfied by the submittal of sales literature
and data needed to demonstrate compliance; may be satisfied by submittal of
information accrued during manufacturer self-imposed diagnostic testing to
assure themselves that conforming products are being distributed in commerce,
The regulation has also been revised so that all data may be mailed to EPA
in lieu of the proposed telephone reporting requirements.
4.14 Several commenters indicated that the proposed regulations in
some instances required the repetitive submission of information.
A-57
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The final regulation provides that where information has been
previously submitted and has remained unchanged, subsequent reports need
only refer to the previous submissions.
The regulation has been revised so as to permit execution by an
authorized company representative in lieu of a Corporate Vice President
of reports required to be filed by a manufacturer.
4,15 One commenter felt that the cease to distribute orders went beyond
the statute and should be modified.
The Agency has interpreted Section 11(d) of the Act, which provides
for the issuance of administrative orders, as inclusive of the power to
issue cease to distribute orders and recall orders. Any such orders
would be preceded by notice and opportunity for a hearing.
4.16 One commenter felt that the statement contained in the proposed
regulation, "all costs associated with recall and remedy of noncomplying
compressors shall be borne by the manufacturer" could be interpreted
very broadly.
The costs normally associated with a recall are the costs of con-
ducting the campaign itself, as well as the cost of remedying the noncon-
formity, including parts and labor. These are the costs the manufacturer
would be required to absorb.
4.17 Several cominenters felt the costs of the administrative enforcement
provisions would be significant because of the large number of products
that would be required to be tested as a result of the production verifi-
cation and audit tests, the record keeping and reporting requirements,
A-5 8
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and the costs of constructing added test facilities to accomplish all the
required testing.
EPA has reexamined the cost impacts of the administrative enforcement
provisions of production verification and selective enforcement auditing
and has found them to be reasonable. As a result of information gathered
during the rulemaking process, which included a public hearing and many
written submissions to the docket, modifications were made to the regu-
lation in the area of the administrative enforcement provisions.
These modifications have reduced the record keeping and reporting re-
requirments, and have made 'the product verification and selective enforce-
ment audit processes more flexible and tailored to the industry. These
changes in themselves have resulted in additional reductions in cost to
the manufacturer over those that- would have been incurred based on the
proposed regulation.
Significant capital expenditures can be eliminated by those manu-
facturers who avail themselves of the EPA Enforcement Test Facility at
Sandusky, Ohio, in lieu of constructing additional facilities.
4.18 Several commenters were concerned that the warranty required by
Section 204.58-1 of the proposed regulation was a useful life performance
warranty.
The warranty required of the manufacturer is a performance warranty
that the air compressor met the noise emission standards on the date of
sale to the ultimate purchaser. Because performance is warranted for the
date of sale only, warranty claims must relate back to a nonconformity
A-59
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on that day. To make the best case in relating back to the date of
sale, the claimant should be able to point to a defect in design,
materials, or workmanship which existed on the sale date and which
caused noise emissions to exceed the standard. Thus, although the
claim may be made against the manufacturer at any time during the
life of the compressor, such claim must relate back to noncompliance
on the date of sale.
4.19 One commenter wished clarification regarding which "manufacturer"
must issue the noise emission warranty.
The manufacturer who is required to issue and honor the noise emis-
sion warranty is the manufacturer who is required to production verify.
The fact that a defective part, component, or system was purchased from
another manufacturer does not alter this warranty. Manufacturers who
production verify may seek indemnification from suppliers for liability
which is attributable to the supplier.
4.20 Some commenters asked for a definition of what constitutes tamper-
ing and whether the use of aftermarket parts (parts not manufactured or
authorized by the original equipment manufacturer) would constitute
tampering.
A list of acts which could adversely affect the noise control
system of a compressor and would constitute tampering, as determined
by EPA, will be published in the owner's manual. This will give spe-
cific indications of those acts which will be considered tampering by
A-60
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the Agency unless it can be shown that noise emissions are not adversely
affected by the act.
In general, in terms of noise-related aftermarket parts, any non-
original equipment aftermarket part (including a rebuilt part) may be
installed in or on a compressor subject to these regulations if the
installer has a reasonable basis for knowing that it will not adversely
affect noise emissions. For noise-related replacement aftermarket parts,
a reasonable basis exists if (a) the installer reasonably believes that
the replacement part or rebuilt part is designed to perform the same
function with respect to noise control as the replaced part, or (b) the
replacement part or rebuilt part is represented in writing by the part
manufacturer or rebuilder to perform the same function with respect to
noise control as the replaced part.
For noise-related add-on, auxiliary, augmenting, or secondary
parts or systems, a reasonable basis exists if (a) the installer knows
of noise emissions tests which show that the part does not cause noise
emissions to exceed the time-of-sale standards, or to increase emis-
sions, if the noise emissions already exceed the time-of-sale standards;
or (b) the part or system manufacturer represents in writing that tests
have been performed with similar results (to (a) above); or (c) a Fed-
eral, State or local environmental control agency with appropriate
jurisdiction expressly represents that a reasonable basis exists.
4.21 Some commenters indicated that in the tampering requirement, sub-
mission of information 90 days before introduction into commerce of the
compressor represents an excessively long time period for the manufacturer.
A-61
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The 90-day requirement in the proposed regulation was established
to allow EPA sufficient time to evaluate the tampering data, prepare a
list of the acts which tampering enforcement would focus on, and then
forward this list to the manufacturer for incorporation into the owner's
manual. However, to account for the varying production schedules of
manufacturers, the final regulation has been changed to allow for a time
period based on the need of the manufacturer. The regulation now requires
that the manufacturer submit the requested information within an adequate
amount of time to provide EPA with 30 days to review the data and return
a tampering list to the manufacturer for printing in the owner's manual.
If the Administrator fails to provide the list to the manufacturer within
30 days of the date the information was submitted, the manufacturer is
not precluded from distributing the compressors into commerce. In this
case, the list of tampering acts required in the owner's manual shall
be omitted until the list is provided and the owner's manual is other-
wise reprinted.
4.22 Several commenters considered unreasonable and burdensome the
requirements for the submission of listings of noise control devices
and elements of design (including performance specifications) and acts
which might constitute tampering.
The purpose of these requirements in the proposal was to enable
the Administrator to determine what acts will constitute tampering.
Information submitted by the manufacturer is not to be considered as
a final judgment of what constitutes tampering, but will only provide
A-62
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the basic information for determination by the Administrator. The final
regulation has been modified so that no separate submission of the list
of noise control devices and elements of design is required; this is
part of the information required to be provided in the product verifica-
tion report. The requirement for submission of noise-related performance
specifications has been deleted. The generation of the required infor-
mation by the manufacturer can be performed concurrently with the
development of appropriate noise control systems. The testing that will
normally be performed in the development of the noise control systems
and the manufacturer's engineering experience should provide a substantial
basis from which the required information can be generated.
5. Miscellaneous
5.1 One commenter stated that noise regulations directed at the end
product are preferable to those for individual component parts.
The Agency has carefully reviewed the possibility of regulating
equipment components, for example, an engine as opposed to the total
final end product, and reached the conclusion that on a cost effective
basis, it is indeed preferable to regulate end products. This is so
because in the synthesis of a final product from various regulated
components, there is no guarantee that the noise emissions of the final
product will be within acceptable limits. Accordingly, there probably
still would be a need for a final product regulation.
A-63
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5.2 One commenter stated that the regulation should be rewritten to
improve the language related to the numerical descriptions of noise.
The Agency has taken the comment under advisement, and accordingly
changes have been made to the text of the regulation.
5.3 One commenter suggested that the definition of portable air com-
pressor should be clarified to exclude any products not intended to be
subject to the regulation.
The suggested changes presented by this commenter were studied
and the definitions of portable air compressors now appearing in the
regulation incorporates language which the Agency feels adequately
defines the product intended for regulation.
A-64
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APPENDIX B
METHOD TO EVALUATE THE IMPACT OF
PORTABLE AIR COMPRESSOR NOISE
ON PUBLIC HEALTH AND WELFARE
-------
Appendix B
METHOD TO EVALUATE THE IMPACT OF PORTABLE AIR COMPRESSOR
NOISE ON PUBLIC HEALTH AND WELFARE
SPECIFICATION OF NOISE ENVIRONMENT
Environmental noise is defined in the Noise Control Act of 1972 as the
"intensity, duration, and the character of sounds from all sources1', A
measure for quantifying environmental noise must evaluate not only these
factors, but must also correlate well with the various modes of response of
humans to noise and be simple to measure (or estimate}.
EPA has chosen the equivalent A~weighted sound pressure level in decibels
as its basic measure for environmental noise. The general symbol equivalent
level is L , and its basic definition is:
eq
Leq-101°g10
i2"
1
2
P° J
where tg - t^ is the interval of time over which the levels are evauiated, p(t) is
the time varying sound pressure of the noise, and p is a reference pressure.
standardized at 20 micropascal.
When expressed in terms of A-weighted sound level (L. ), I,
A eq
as:
may be defined
L =10 log, „
eq &10
10
at
J
(B-2)
B-i
-------
The primary interval of interest for residential and similar land uses is a
twenty-four hour period, with weighting applied to nighttime noise levels to
account for the increased sensitivity of people associated with the decrease in
background noise levels at night. This 24-hour weighted equivalent
level is called the Day-Night Equivalent Level, and is symbolized as L, . The
dn
basic definition of L, in terms of A-weighted sound level is:
dn
L. L + 10
d n
(15 x 1010) + (9 x 10 10
(B-3)
where L, is the "daytime" equivalent level, obtained between 7a.m. and
d
10 p.m. and L^ is the "nighttime" equivalent level obtained between 10 p.m.
and 7 a.m. of the following day.
ASSESSING IMPACT FROM ENVIRONMENTAL NOISE
The underlying concept for noise impact assessment in the following
analysis is to relate the change in expected impact in terms of the number of
people involved to the change that will result in the acoustical environment as a
result of the proposed action. Three fundamental components are involved in the
^
analysis:
1. Definition of the initial acoustical environment,
2. Definition of final acoustical environment, and
3. Relationship between noise environment and human impact.
B-2
-------
The first two components of the assessment are entirely site or system
specific, relating to either estimates or measurement of the environmental
noise before and after an action is taken. The same approach is used concep-
tually whether one is examining one house near a highway, a house near a con-
struction site, the transportation system in general, or whatever noise source
is involved. The methodology for estimating the noise environment in each
case will vary widely, but the concept remains the same.
In contrast to the large number of methodologies that may be utilized to
estimate the noise environment, the relationship to human response can be
quantified by a single methodology in terms of the number of people in occupied
places exposed to noise of a specified magnitude. This is not to say that
individuals have the same susceptibility to noise; they do not. Even groups of
people may vary in response depending upon previous exposure, age, socio-
economic status, political cohesiveness and other social variables. In the
aggregate, however, for residential location the average response of groups of
people is quite stably related to cumulative noise exposure as expressed in
measures such as L . The response considered is the general adverse
reaction of people to noise. This response is a combination of such factors
as speech interference, sleep interference, desire for a tranquil environment,
and the ability to use telephones, radio and TV satisfactorily. The measure of this
response is related to the percent of people in a population that would be
expected to indicate a high annoyance to noise for a specified level of noise
exposure.
For schools, offices, and similar spaces where criteriajor speech com-
munication or a possibility of damage to hearing is of primary concern, the
same averaging process is used to estimate the potential response of people
as a group, again ignoring the individual variation 01 one person as compared
to another.
B-3
-------
Hence, in both residential and non-residential areas alike, the variation of the
average response of people as a function of environmental noise exposure is
considered.
A detailed discussion of the relationship between noise and human response
fl 28~1
is provided in EPA documents L ' in which hearing damage, speech and other
activity interference and annoyance are related to L0_ and L^n. For the purposes
eq on
of this study, criteria presented in the "EPA Levels Document" u J are used.
Further, it is considered that if the levels identified in the document are
met, then no impact exists on the public health and welfare. Thus, we define
that if the levels identified in the "Levels Document" are met, a zero percent
impact exists. That is, if an L^ of 55 measured outdoor exists, then there is
no impact in terms of annoyance and general community response from noise.
Similarly, if an L^ of 45 exists indoors, which translates to an LJ^ of 55 out-
doors (assuming a 10 dB transmission loss with windows partially opened) then no
interference exists with respect to speech.
Observation of the data presented in Appendix D of Reference 1 allows the
specification of an upper limit, that is a bound corresponding to 100% impact.
ft may be observed in Figure D-7 of the "Levels Document" *• ' that community
reaction data show that the expected reaction to an identifiable source of intruding
noise changes from "none" to "vigorous" when the day-night sound level increases
from 5 dB below the level existing without the presence of the intruding noise to
19.5 dB above the pre-intrusion level. When the combined values of the intruding
noise and the pre-intrusion noise levels are considered, the changing community
reaction from "none" to "vigorous" occurs when the level increases by 19. 7 above
the pre-intrusion level. For simplicity sake, it is reasonable to associate 100
percent impact corresponding to a vigorous community reaction with a change of 20
B-4
-------
dB above the L value identified as a zero impact level. Thus, for the purpose
dn
of this analysis, L, = 75 is considered to be a 100 percent impact.
dn
Furthermore, the data in Appendix D of Reference 1 suggest that within
those upper and lower bounds the relationship between impact and level varies
linearly, that is, a 5 dB excess constitutes a 25 percent impact, while a 19 dB excess
constitutes a 50 percent impact.
The data presented in the "Levels Document" with respect to activity inter-
ference (e. g., speech interference) suggests that if the day-night sound level
indoors is 45 dB, no impact exists on speech communication since a noise
level intelligibility for all types of speech material and would have a calculated
articulation index of 1. 0.
The intelligibility of speech is a function of the material presented to the
listener as well as the signal to noise ratio.
It may be argued that for most conversation, the material the listener nor-
mally listens to is in the form of sentences containing a mixture of some known
material and some unknown material. Thus, for this analysis it is reasonable
to average the data on known and unknown sentences. Observation of Figure 15
[29]'
of the ANSI Standard reveals that when the noise environment is increased by
approximately 19 dB above the level identified in the "Levels Document," *- the
intelligibility of sentences of unknown material drops 90 percent. Similarily, the
intelligibility for sentences of known material drops to 90 percent when the level is
increased by 22 dB above the level identified by EPA and 50 percent when the level is
increased by approximately 26 dB. Thus, if the values are averaged, it is not
unreasonable to assume that a 20 dB increase in the noise level above the level
identified by EPA in the "Levels Document" will result in conversational speech
-------
deteriorating rapidly with each decibel of increase. For this reason, it is assumed
that 100 percent impact will occur on speech intelligibility when the level of the
enivronmental noise increases 20 dB above the identified level in the "Levels
[29]
Document." Furthermore, observation of Figure 15 of the ANSI Standard
suggests that it is reasonable to assume that speech varies approximately linearly
with the level for the range between 0 and 100% impact. That is, with each 5 dB
excess of noise above the level identified in Reference 1, a 20 percent reduction
of speech intelligibility occurs while a 10 dB excess results in a 50 percent
degradation.
The previous paragraphs presented information to show that increases in
noise levels above a certain base level would cause annoyance, adverse com-
munity reaction and/or adverse effects on speech interference. With 0 percent
impact associated with the base level and 100 percent impact associated with a
level 20 dB above the base level, one is able to calculate the percentage impact
resulting from any noise level. For convenience of calculation, the percentage
impact may be expressed in terms of a Fractional Impact (FI), where FI is
calculated in accordance with the following formula:
FI = 0.05 x {L - Lc) for L > LC
FI = 0 for L s LC
where L is the environmental noise level, expressed either in L^ or L , and
L is the base level identified in the "Levels Document."
c*
The appropriate level for the computation of FI is L^ = 55 dB for residential
area measured outdoors. For those analyses concerned with office buildings and
other type of spaces in which speech communication is the principal factor of concern,
B-6
-------
the identified level is L, « _ ..doors, which can be translated to an outdoor
an
level by using sound level reduction appropriate to the type of structure.
Data on the reduction of aircraft noise afforded by a range of residential
structures are available. These data indicate that houses can be approximately
categorized into "warm climate" and "cold climate" types. Additionally, data
are available for typical open-window and closed-window conditions. These data
indicate that the sound level reduction provided by buildings within a given
community has a wide range due to differences in the use of materials, building
techniques, and individual building plans. Nevertheless, for planning purposes,
the typical reduction in sound level from outside to inside a house can be sum-
marized as follows in Table B-l. The approximate national average "window-
open" condition corresponds to an opening of 2 square feet and a room absorption
of 300 sabins (typical average of bedrooms and living rooms). This "window-
open" condition has been assumed thoughout this chapter in estimating conser-
vative values of the sound levels inside dwelling units that results from outdoor
noise.
The final notion to be considered is the manner in which the number of
people affected by environmental noise is introduced into the analysis. The
magnitude of the total impact associated with a defined level is calculated by
formula B-5, i. e., the product of the number of people and the fractional impact
associated with the level of the environmental noise:
Peq = (FI) P (B-5)
where P is the magnitude of the total impact on the population and is numerically
eq
equal to the equivalent number of people having a fractional impact equal to unity
(100% impacted); FI is the fractional impact for the level and P is the population
affected by the noise.
B-7
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TABLE B-l
TYPICAL ATTENUATION OF OUTDOOR NOISE BY THE
EXTERIOR SHELL OF HOUSES
Warm climate
Cold climate
Approximate national average
Windows
Open
12 dB
17 dB
15 dB
Windows
Closed
24 dB
27 dB
25 dB
B-8
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Since the levels of environmental noise associated with the source(s) decrease
as the distance between the source and receiver increases, the magnitude of the
total impact may be computed by determining the number of people exposed at
each level, and summing the resulting impact. The total impact is given by the
following formula:
Peq - E PjFIj
-------
people in the United States exposed to various levels of urban noise. Data in the
study are used to illustrate the impact assessment procedure, to show the current
impact resulting from urban noise and to assess the change in impact if urban
noise were reduced 5, 10, or 15 dB. For this example, the base level (outdoors)
is an L, of 55 dB.
dn
The results, provided in Table B-2, show that a 5 dB noise reduction
results in a 55 percent reduction in impact, a 10 dB noise reduction results in an
85 percent reduction in impact, and a 15 dB noise reduction results in a
96 percent reduction in impact.
The impact assessment procedure may be summarized by the following
steps:
1. Estimate the L or L, produced by the noise source system as a
eq dn
function of space over the area of interest.
2. Define subareas of equal L or L, , in increments of 5 dB, for all
eq dn
land use areas.
3. Define the population, P., associated with each of the subareas of
step 2.
4. Calculate the FI. values for each L, or L obtained in step 2.
i dnj eqj
5. Calculate FI x P for each subarea in step 2.
6. Obtain the equivalent impacted population for the condition existing
before the change being evaluated, by summing the individual contributions of
step 5.
Peq -£ (FIiXlV
^B i
B-10
-------
7. Repeat steps 1-6 for the noise environment existing over the area of
interest after the change being evaluated takes place, thus obtaining
8. Obtain the percent reduction in impact from
(P - P )
^B eqA
A« 100 - - 2_
B-ll
-------
TABLE B-2
ESTIMATE OF THE IMPACT OF SUCCESSIVE REDUCTION OF
ALL URBAN NOISE SOURCES IN 5 DECIBEL INCREMENTS
Current Conditions
Ldn
-dB
55
60
65
70
75
80
Population
exposed to
higher Ldn
-millions
93.4
59.0
24.3
6.9
1.3
0.1
Pi
millions
34.4
34.7
17.4
5.6
1.2
0.1
Total equivalent
people impacted
Percent reduction
impact
Noise reduction in decibels
0
FI. FI. P
-millions
0.125 j 4.3
0.375 1 13.0
0.625 j 10.9
0. 875 1 4. 9
1
1.125 | 1.4
1.375 1 0.1
1
34.6
0
5
FI. FI.P,
-millions
0 j 0
0.125 1 4.3
0. 375 6. 5
0.625 ' 3.5
1
0.875 | 1.1
1.125 I 0.1
t
15.5
55
10
FI FI P
i I i
- millions
0 [ 0
0 | 0
0.125 1 2.2
1
0.375 2.1
1
0.625 I 0.8
0. 875 0. 1
j
5.2
85
15
FIt FT,?,
-millions
0 j 0
0 ! 0
1
0 j 0
0. 125 1 0. 7
I
0.375 i 0.5
0.625 I 0.1
i
1.3
96
t-J
-------
APPENDIX C
COST ANALYSIS OF PRODUCTION VERIFICATION
AND SELECTIVE ENFORCEMENT AUDITING FOR THE
PORTABLE AIR COMPRESSOR INDUSTRY
-------
APPENDIX C
COST ANALYSIS OF PRODUCTION VERIFICATION
AND SELECTIVE ENFORCEMENT AUDITING FOR
THE PORTABLE AIR COMPRESSOR INDUSTRY
An analysis has been performed to estimate the costs associated with typical manu-
facturer production verification testing and selective enforcement audit testing.
For the analysis, it was assumed that most of the testing would be done at the manu-
facturer's facility. However, because some manufacturers may prefer not to construct a
test facility, an EPA facility will be available for their use for a fee, which will cover actual
costs incurred by the Government. Data from Reference 8 and the assumptions listed in
Table C-1 served as the basis for the analysis.
PRODUCT VERIFICATION TESTING COSTS
Based on results from the analysis, it has been estimated that the total cost to the in-
dustry for production verification testing during the first year of compliance might range
from $76,000 to S 107,117. The $76,000 figure assumes that all testing is done at manu-
facturer test facilities, whereas the $107,117 figure assumes that all testing is done at the
EPA test facility. A single figure for the product verification costs should lie somewhere
between these two values. In subsequent years, product verification testing costs can be
expected to decrease due to manufacturers' ability to utilize the initial production verifi-
cation report for compressor models for which no change has been made in the compressor
for the next model year.
Estimates of production verification testing costs at individual manufacturer facilities
range from a high of $ 14,000 for the largest manufacturer to a low of $300 for the smallest
manufacturer, the mean value being $4471. Estimates of production verification testing
conducted at theiEPA test facility on an individual company basis range from $19,800 for
the largest manufacturer to $354 for the (smallest manufacturer, the mean value being
$6301.
SELECTIVE ENFORCEMENT TESTING COSTS
Selective enforcement audit (SEA) testing may be conducted by the manufacturer
both on his own initiative and upon request by EPA. Costs associated with testing requested
C-l
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Table C-l
ASSUMPTIONS USED TO ESTIMATE
PORTABLE Am COMPRESSOR TESTING COSTS
Report Preparation Costs
All report costs are based on $100/test (one day at $25K per man
year)
Transportation Costs
(For Two Products)
Fixed
$30.00 (Basic cost of short haul)
Variable
16 cents/mile Driver ($8.00/hr or $16.00/100 miles)
20 cents/mile Truck (12 cents/mi, for fuel, 8 cents/mi, maintenance
+ depreciation)
36 cents/mile = Total variable cost
Summary
$30.00 + $. 36/mi. (Transport 2 Products)
$15.00 + $.18/mi. (Transport 1 Product)
Total Transportation Cost = Number of Categories X ($15 + $.18 X route miles)
Cost of Testing
The cost of conducting the measurement methodology is estimated to be
approximately $200. However, if a manufacturer supplied an estimate which
reflects his actual costs, then his estimate was used for the analysis.
Total Number of Categories
The total number of categories for the industry requiring production
verification is estimated to be 236.
C-2
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by EPA and conducted at the manufacturer's facility are estimated to total $149,000 for
the industry as a whole. Included in the $149,000 figure is an estimate of $42,000 for
the largest manufacturer and an estimate of $3000 for the smallest manufacturer. The
industry average cost for SEA testing is estimated to be $8,765.
Manufacturers may be expected to request use of the EPA test facility to conduct
selective audit testing to primarily determine the level of performance of their products.
Costs associated with this testing, including transportation of the test compressors to the
facility, are estimated to total $206,522 for the industry during the first year of compliance.
The cost breakdown within the industry ranges from a high of $57,628 to low of $3,540,
the average value being $12,148. These costs can be expected to decrease following the first
year the regulations are effective as manufacturers become more familiar with the compliance
scheme, the production variance of their products, and the correlation of results at their
facility with those at the EPA facility.
Finally, based on the assumption that SEA testing will be conducted at the EPA test
facility upon EPA request, it is estimated that a $72,332 cost per year might accrue to the
industry for such testing. This figure represents the cost of transportation only, since EPA
would conduct the testing at its own expense. In terms of individual manufacturer trans-
portation costs, it is estimated that a $21,628 cost might accrue for the largest manufacturer
and a $540 cost for the smallest manufacturer. The mean transportation cost for the
industry is estimated to be $4,255.
Table C-2 summarizes the estimates discussed above.
C-3
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Table C-2
SUMMARY OF ENFORCEMENT COSTS
PRODUCTION VERIFICATION
TOTAL
AVERAGE
HIGH
LOW
MEDIAN
Manufacturer
$76,000
$ 4,471
$14,000
$ 300
$ 3,300
EPA*
$107,117
$ 6,301
$ 19,800
$ 354
$ 4, 422
* Manufacturer's request
SELECTIVE ENFORCEMENT AUDITING
TOTAL
AVERAGE
HIGH
LOW
MEDIAN
Manufacturer
$149, 000
8,765
$ 42,000
$ 3, 000
$ 3,000
EPA*
$206, 522
$ 12,148
$ 57,628
$ 3, 540
$ 5,094
EPA**
$72,332
$ 4,255
$21,628
$ 540
$ 1,920
* Manufacturer's request
** EPA's request
C-4
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