EPA-600/2-90-008
March 1990
USERS GUIDE FOR THE CONVERSION OF
NAVY PAINT SPRAY BOOTH PARTICULATE
EMISSION CONTROL SYSTEMS FROM
WET TO DRY OPERATION
By
Jacqueline Ayer
Darrel Tate
Acurex Corporation
Environmental Systems Division
485 Clyde Avenue, P.O. Box 7044
Mountain View, California 94039
EPA Contract 68-02-4285 WA 2/026
U.S. Navy Project Engineer: Richard M. Roberts
Energy Conservation and Environment
Code L74
Naval Civil Engineering Laboratory
Port Hueneme, California 93043-5003
EPA Project Officer: Charles H. Darvin
Air and Energy Engineering Research Laboratory
Office of Research and Development
United States Environmental Protection Agency
Research Triangle Park, NC, 27711
i
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ABSTRACT
This guide provides users with instructions and cost evaluation information for converting
the water curtain particulate emission control system currently used on many Navy painting
facilities to dry filter operation. Engineering and logistical issues are addressed, and sample
design plans are provided. Construction and operating permit requirements mandated by
regulatory agencies, such as air pollution control districts and fire departments, are discussed.
Cost estimates that may be used to perform comprehensive cost evaluation analyses are
provided. In addition, sample calculations that illustrate how to use the cost data are included.
NOTICE
This document has been reviewed in accordance with
U-S- En\ironmenial Protection Agency policy and
approved for publication. Mention of trade names
or commercial products does not constitute endorse-
ment or recommendation for use.
ii
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CONTENTS
Abstract ii
Figures v
Tables vii
Metric Conversion Factors viii
Glossary of Terms ix
1 INTRODUCTION 1
1.1 BACKGROUND 1
1.2 OBJECTIVE 2
1.3 APPROACH 2
1.4 USERS GUIDE ORGANIZATION 2
2 NAVY PAINT BOOTH CHARACTERISTICS 4
2.1 SURVEY DESCRIPTION 4
2.2 SURVEY RESULTS 4
3 GUIDELINE CONSTRUCTION WORK PACKAGE 8
3.1 GENERAL CONVERSION ISSUES AND INSTRUCTIONS 8
3.1.1 Dry Filter System Selection 8
3.1.2 General Engineering Design Issues and Instructions 11
3.1.3 Shutdown/Access/Laydown Arrangements 12
3.2 SPECIFIC INFORMATION AND STEP-BY-STEP INSTRUCTIONS FOR
THE CONVERSION OF A CROSSDRAFT PAINT SPRAY BOOTH 13
3.2.1 General Discussion 13
3.2.2 Crossdraft System Conversion Procedures 13
3.3 SPECIFIC INFORMATION AND STEP-BY-STEP INSTRUCTIONS FOR
THE CONVERSION OF A DOWNDRAFT PAINT SPRAY BOOTH 18
3.3.1 General Discussion 18
3.3.2 Downdraft System Conversion Procedures 18
4 PERMITTING PROCESSES 24
4.1 AIR EMISSIONS REGULATORY AGENCY PERMIT PROCEDURES
AND INFORMATION 24
iii
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CONTENTS
4.1.1 Permitting Procedures 24
4.1.2 Air Emissions Regulatory Agency Information for NSYs
and NADEPs Located in the United States 25
4.1.3 Paint Booth Modification Permit Application Processes
in Two Target Areas 27
4.2 HEALTH, SAFETY AND BUILDING PERMITS 35
4.3 DISPOSAL OF SPENT FILTER MEDIA 42
4.3.1 General Requirements 42
4.3.2 Filter Waste Disposal Information For NSYs and NADEPs
Located Across the United States 42
4.3.3 Filter Waste Disposal Processes in Three Target Areas 44
5 COST/BENEFIT ANALYSIS 46
5.1 ECONOMIC ANALYSIS TECHNIQUES 46
5.1.1 Identification and Estimation of all Costs 47
5.1.2 Calculation of the Savings to Investment Ratio 47
5.1.3 Determination of the Discounted Payback Period 48
5.2 IDENTIFICATION AND ESTIMATION OF PECS CONVERSION
COSTS 48
5.2.1 Retrofit System Installation Cost 48
5.2.2 Water Curtain And Dry Filter System Operating Costs 49
5.2.3 System Reliability, Availability, and Maintainability 56
5.3 ECONOMIC EVALUATION EXAMPLES: THE APPLICABILITY OF
THE CONVERSION OPTION FOR THREE DIFFERENT PAINT
SPRAY BOOTHS 56
5.3.1 Conversion of a Small Crossdraft Paint Booth 56
5.3.2 Conversion of a Large Crossdraft Paint Booth 60
5.3.3 Conversion of a Large Downdraft Paint Booth 65
APPENDIX A—DRY FILTER SYSTEM CHARACTERISTICS 70
iv
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FIGURES
Figure Page
1 Questionnaire mailed to NSY and NADEP paint booth operators 5
2 Diagram of a typical crossdraft paint spray booth equipped with
a water curtain PECS 16
3 Diagram of a retrofit crossdraft paint spray booth equipped
with a dry filter PECS 17
4 Diagram of a downdraft paint spray booth equipped with
a water curtain PECS 21
5 Diagram of a retrofit downdraft paint spray booth equipped
with a dry filter PECS 22
6 SCAQMD Paint Spray Booth Permit Form 400A (Front) 29
7 SCAQMD Paint Spray Booth Permit Form 400A (Back) 30
8 SCAQMD Paint Spray Booth Permit Form 400-C-l (Front) 31
9 SCAQMD Paint Spray Booth Permit Form 400-C-l (Back) 32
10 SCAQMD Paint Spray Booth Permit Form 400B (Front) 33
11 SCAQMD Paint Spray Booth Permit Form 400B (Back) 34
12 Commonwealth of Virginia SAPCB Form 7(Section E.l Pgl) 36
13 Commonwealth of Virginia SAPCB Form 7(Section E.l Pg2) 37
14 Commonwealth of Virginia SAPCB Form 7(Section E.3 Pgl) 38
15 Commonwealth of Virginia SAPCB Form 7(Section E.3 Pg2) 39
16 Commonwealth of Virginia SAPCB Form 7(Section E.3 Pg3) 40
17 Commonwealth of Virginia SAPCB Form 7(Section E.3 Pg4) 41
18 Cash flow diagram: current operation of a small crossdraft booth 61
v
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FIGURES (CONCLUDED)
Figure Page
19 Cash flow diagram: proposed operation of a small crossdraft booth 61
20 Cash flow diagram: current operation of a large crossdraft booth 64
21 Cash flow diagram: proposed operation of a large crossdraft booth 64
22 Cash flow diagram: current operation of a large downdraft booth 68
23 Cash flow diagram: proposed operation of a large downdraft booth 68
A-l Schematic diagram illustrating the pleated paper filtration process 72
vi
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TABLES
Table Page
1 NSY PAINT SPRAY BOOTH SURVEY RESULTS 6
2 NADEP PAINT SPRAY BOOTH SURVEY RESULTS 7
3 DRY FILTER SYSTEM CHARACTERISTICS 9
4 CAPITAL AND INSTALLATION COSTS OF CONVERTING WATER
CURTAIN PECS'S TO DRY FILTER OPERATION 48
5 PRESENT VALUE OF HONEYCOMBED PAPER FILTER REPLACE-
MENT COST OVER THE 10 YEAR ECONOMIC LIFE OF THE
PAINT BOOTH 50
6 PRESENT VALUE OF CLOTH ROLL FILTER REPLACEMENT COST
OVER THE 10 YEAR ECONOMIC LIFE OF THE PAINT BOOTH 50
7 PRESENT VALUE OF PLEATED PAPER FILTER REPLACEMENT
COST OVER THE 10 YEAR ECONOMIC LIFE OF THE PAINT
BOOTH 51
8 PRESENT VALUE OF FIBERGLASS CARTRIDGE FILTER
REPLACE-MENT COST OVER THE 10 YEAR ECONOMIC LIFE OF
THE PAINT BOOTH 51
9 SLUDGE AND/OR WASTEWATER DISPOSAL COSTS 52
10 ELECTRICAL OPERATING COSTS AS A FUNCTION OF
HORSEPOWER 54
11 LABOR COSTS ASSOCIATED WITH FILTER REPLACEMENT 55
12 LABOR COSTS ASSOCIATED WITH SUMP SYSTEM
MAINTENANCE 55
13 SUMMARY OF ONE-TIME AND RECURRING COST ESTIMATES
FOR A SMALL CROSSDRAFT BOOTH BEFORE AND AFTER
CONVERSION 59
14 SUMMARY OF ONE-TIME AND RECURRING COST ESTIMATES
FOR A LARGE CROSSDRAFT BOOTH BEFORE AND AFTER
CONVERSION 63
15 SUMMARY OF ONE-TIME AND RECURRING COST ESTIMATES
FOR A LARGE DOWNDRAFT BOOTH BEFORE AND AFTER
CONVERSION 6?
vii
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METRIC CONVERSION FACTORS
Readers more familiar with the metric system may use the following factors to convert the
non-metric units in the report to metric units.
English units Multiply by To Obtain
in 2.54 cm
ft 0.305 m
ft2 0.0929 m2
ft3 0.0283 m3
gal 3.79 liter
hp 0.746 kW
lb 0.454 kg
viii
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GLOSSARY OF TERMS
Air Supply Duct(s)
BACT
Crossdraft Booth
Discounted Payback
Period
DOHS
Downdraft Booth
Exhaust Duct(s)
Face Velocity
IWTP
Laydown
NADEP
NAVFAC P-442
NPV
NSPS
NSY
O&M
Particulate Capacity
Particulate Removal
Efficiency
PECS
Resistance to Airflow
The duct(s) through which fresh make-up air is supplied to the paint
booth. The duct(s) are generally equipped with forced draft fans
Best Available Control Technology
A booth in which the ventilation air flows horizontally
Time required to accrue sufficient present value savings to offset
the investment cost.
Department of Health Services
A booth in which the ventilation air flows vertically
The duct(s) through which contaminated paint booth air is vented
to the outside. The duct(s) are generally equipped with induced
draft fans
The linear velocity of air flow through a filter
Industrial Waste Treatment Plant
Procedures and space allocated for equipment maintenance and/or
alteration
Naval Aviation Depot
Naval Facilities Engineering Command P-442 Economic Analysis
Handbook
Net present value
New Source Performance Standards: Federal standards that specify
pollutant emission control requirements
Naval Ship Yard
Operating and Maintenance
The maximum quantity of overspray particulate that a filter retains
The percent of overspray particulate captured by a filter
Particulate Emission Control System
The pressure differential across a filter due to the filter media and
the paint overspray particulate collected in the media
IX
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SECTION 1
INTRODUCTION
This Users Guide is the culmination of work performed for the United States Navy's
Naval Civil Engineering Laboratory (NCEL) under the auspices of the United States
Environmental Protection Agency's (EPA's) Air and Energy Engineering Research Laboratory
(AEERL). The work was performed under EPA Contract No. 68-02-4285 WA 2/026. This
Users Guide presents step-by-step instructions for the conversion of water curtain particulate
emission control systems currently used on most Navy paint spray booths to dry filter operation.
In addition, cost estimate information is provided for the purposes of performing cost/benefit
evaluations for the proposed conversion. The cost/benefit information presented was prepared
according to NAVFAC P-442 procedures.
1.1 BACKGROUND
The Navy is currently exploring the possibility of reducing the quantities of hazardous
waste generated in many industrial Navy processes. One hazardous waste generating source
targeted for waste minimization efforts is the particulate emission control system (PECS) used
on nearly every Navy paint spray booth. The most common PECS utilizes a water curtain to
remove paint overspray particulate from the booth exhaust.
The large volume of contaminated wastewater generated by the water curtain PECS
contains paint particulate, solvents, and in some cases, flocculating and coagulating agents. The
wastewater must be treated and the hazardous constituents removed (often at great cost to the
generating facility) before it may be discharged to a municipal treatment plant.
The waste minimization option that the Navy is exploring is the replacement of water
curtain PECSs with dry filter systems at Navy painting facilities. Dry filter systems are capable
of controlling particulate emissions from paint booths with the same high efficiency associated
with water curtain systems.
The conversion of PECSs from wet to dry operation will result in a number of benefits,
such as:
• Paint booth hazardous waste disposal costs are eliminated or significantly reduced.
• The energy demand for operating dry filter systems is lower than for water curtain
systems.
• Unlike water curtain systems, which tend to rust, dry filter systems do not
deteriorate with age if properly maintained.
1
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• The reliability, availability and maintainability of dry filter systems are generally
as high or higher than those of water curtain systems.
• The working conditions are often greatly improved due to the elimination of water
curtain sump odors.
Water curtain systems generate large quantities of contaminated wastewater which, as
described previously, must be disposed of as hazardous waste. However, dry filter PECSs
generate spent filter media that is caked with paint solids. These spent filters are generally not
classified as hazardous waste, and may therefore be disposed of at a municipal landfill. Thus,
a significant reduction in operating costs may be achieved in the conversion of PECS from wet
to dry operation. The reduction in waste disposal costs, combined with the lower energy
requirement of dry filter systems, results in far lower paint booth operating costs.
An additional advantage of dry filter PECSs is that the low pressure drop across the
system facilitates the integration of a VOC emission control device at the paint booth exhaust.
This is important because increased pressure is being placed on Navy painting facilities by local,
state, and federal agencies to significantly reduce VOC emissions. It is important to note that
neither water curtain nor dry filter systems are capable of reducing VOC emissions from a paint
spray booth.
1.2 OBJECTIVE
The objective of this effort was to provide guidance for the conversion of water curtain
PECSs to dry filter operation by producing a Users Guide that may be used by Navy and
industrial personnel.
1.3 APPROACH
The production of this Users Guide was accomplished in three phases. Phase I was the
classification and characterization of Navy paint spray booths. Phase II was the development
of construction work packages for the conversion of two principal types of paint spray booths.
Phase III was the development of a cost evaluation strategy that may be used to perform a
cost/benefit analysis of the proposed conversion.
To generate a Users Guide applicable to the conversion of all practical sizes and types
of Navy paint spray booths, a thorough understanding of painting operations occurring at Navy
activities was necessary. This information was obtained by conducting a survey of all painting
facilities located on Navy Ship Yard (NSY) and Naval Aviation Depot (NADEP) activities.
Based on this information, the Navy paint spray booth population was classified into two general
types: crossdraft and downdraft. Conversion strategies for these two categories were then
developed. In addition, generalized construction work packages for the two classifications were
developed. Finally, cost/benefit analysis information was gathered, and economic analysis
calculations were performed.
1.4 USERS GUIDE ORGANIZATION
In Section 2, the Navy paint spray booth survey results are presented. Included in this
Section is a discussion of the paint booth classification parameters.
General conversion issues and system design elements relevant to both paint booth
categories are addressed in Section 3. Step by step conversion instructions for each category are
2
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also presented in Section 3. The instructions are accompanied by guideline construction work
packages.
Permitting processes and waste disposal issues are presented and discussed in Section 4.
This section includes a discussion of local, state and federal waste disposal regulations and
permitting procedures for selected areas, and fire and building permits.
The final section contains tabulations and detailed descriptions of installation and
operating costs associated with the conversion of water curtain PECSs to dry filter operation.
"Die data is presented such that the user may easily perform the cost/benefit analysis of a PECS
conversion for virtually any booth. Included in the cost/benefit analysis section are three
examples that illustrate how an economic evaluation is performed. The examples were selected
based on the Navy paint booth survey results, and represent all practical sizes and operations
of Navy painting facilities.
3
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SECTION 2
NAVY PAINT BOOTH CHARACTERISTICS
2.1 SURVEY DESCRIPTION
The Navy operates many paint spray booths at NSY and NADEP activities across the
United States. For the purposes of this Users Guide, it was necessary to characterize and
classify this spectrum of paint booths. To develop the required classification system, a complete
survey of the types, quantities, and duty cycles of NSY and NADEP paint booths was performed.
The survey was conducted by sending a questionnaire to Navy personnel cognizant of paint shop
operations at every NSY and NADEP activity in the United States. A copy of the questionnaire
supplied for each booth is presented in Figure 1.
22 SURVEY RESULTS
The results of the paint booth survey are presented in Tables 1 and 2. Most of the Navy
booths are relatively small crossdraft facilities, although some large downdraft booths are also
used.
Based on the survey results and preliminary retrofit design analyses, Navy paint booths
were divided into two major categories: crossdraft and downdraft. The motivation for this
classification scheme is: (1) retrofit procedures and requirements for crossdraft booths are
independent of booth size; and (2) downdraft booth configurations vary significantly, and require
a more general discussion. This classification scheme is discussed in more detail in Section 3.
The information presented in Tables 1 and 2 was also used to select representative
examples of Navy painting operations for the purpose of developing sample cost/benefit
evaluation calculations. For each of these operations, parameters such as duty cycles and
wastewater treatment methods were selected based on the results of the paint booth survey.
These sample calculations are presented in Section 5.
4
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SURVEY FORM FOR PAINT BOOTHS HAVING WATER CURTAIN SYSTEMS ONLY
Booth location (i.e. building or hangar number)
Approximate booth dimensions (w x 1 x h) and orientation (i.e. is
it completely enclosed, or are one or more sides open?):
This booth is a [crossdraft downdraft] facility (circle one). If
a downdraft facility, where are the water sumps located? (i.e.
above or below floor level, along the sides of the booth, under
the entire floor, etc.)
On average, how many shifts per day is this booth operated?
On average, approximately how much paint is used per week in this
booth?
What is a reasonable estimate of the transfer efficiency of the
paint application system used in this booth?
Are all the coatings applied in this booth air dried? If not,
approximately what percentage of the coatings are not air dried?
Are any chemicals or coagulants added to the sump system in this
booth? If so, approximately how much and how often is each
chemical added?
Approximately what is the sump volume & how often is the sump
drained?
Approximately how much time is required to drain the sump system,
muck out the sludge that collects on the sump bottom, and refill
the system?
Please describe the wastewater treatment method employed (if any)
to process the sump system effluent (i.e. all the water is drummed
and shipped as hazardous waste, or the sump water is drained and
sent to an IWTP, and the sludge from the sump bottom is drummed and
shipped as hazardous waste, etc.).
How many drums of hazardous waste that must be properly disposed
of are generated as a result of this treatment method? What is
the composition of this waste (i.e. water only, sludge only, sludge
+ water, etc)
What types of equipment are painted, and what is the average size
(i.e. dimensions) of the equipment?
In what Air Quality Management District is this Activity located?
Figure 1. Questionnaire mailed to NSY and NADEP paint booth operators.
5
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TABLE 1. NSY PAINT SPRAY BOOTH SURVEY RESULTS
Sunp Wastewater Waste
Booth Nutfcer of Paint Booth Paint Booth Paint Usage Paint Curing Maintenance Treatment Generation
Activity Dimension Booths Type Duty Cycle Rate Method Schedule Method Rate
(ft) (shifts/day) (gal/week) (dri*ns/yr«booth)
Charleston NSY
12x14x14
1
Crossdraft
1
20
Ai r
dried
Once/yr
Water I sludge are
15
Ux35x8
1
Crossdraft
1
20
Air
dried
Once/yr
druimed t shipped
10
20x15x20
1
Crossdraft
1
20
Air
dried
Once/yr
as haz. waste
34
Long Beach NSY
NI
NI
Nt
NI
NI
NI
NI
NI
NI
Mare Island NSY
17x21x3
6
Downdraft
1
3
Air
dried
Once/mo
Water drained to
3
11x16x6.5
1
Crossdraft
1
1
Air
dried
Twice/mo
IWTP; sludge is
1
5x8x6.5
1
Crossdraft
1
1
Air
dried
Twice/mo
drurmed & shipped
1
5x8x6.5
1
Crossdraft
1
1
Air
dried
Twice/mo
as haz. waste
1
Norfolk NSY
4x20x6.5
4
Crossdraft
2
20
Air
dried
Once/yr
Water drained to IWTP;
1
12x15x8
1
Crossdraft
1
15
Air
dried
Once/no
sludge is haz. waste
2
Pearl Harbor NSY
13X12.5X8.5
1
Crossdraft
1
1
Air
dried
1 - 4/mo
Water drained to IWTP;
1
25x9
1
Crossdraft
1
20
Ai r
dried
Twice/yr
sludge is haz. waste
1
Philadelphia NSY
20x10x8
2
Crossdraft
2
50
Air
dried
Once/mo
Wastewater is drained;
24
10x13x10
2
Crossdraft*
1
4
Air
dried
Once/3 mo
sludge is druimed and
2
15.5x10x8
1
Crossdraft*
1
8
Air
dried
Twice/mo
shipped and hazardous
12
14x18x7.5
1
Crossdraft*
1
5
Air
dried
Once/3 mo
waste
<1
Portsmouth NSY
8x10x9
1
Crossdraft*
1
5
Air
dried
Weekly
Water drained to sewer
>1
sludge is haz. waste
Puget Sound NSY
6x8x10
1
Crossdraft
1
10
Air
dried
Once/yr
Water drained to IWTP;
2
9x9x10
1
Crossdraft
1
40
Air
dried
NI
sludge is druimed &
NI
10x10x7
1
Crossdraft
1
2
Air
dried
Twice/yr
shipped as haz. waste
1
10x10x8
1
Crossdraft
1
7
Air
dried
Once/2 mo
II
1
16x13x8
1
Crossdraft
1
20
Air
dried
Once/3 mo
II
5
18x12x12
1
Crossdraft
2
20
Air
dried
Twice/yr
II
6
20x60x20
1
Crossdraft
2
75
Ai r
dried
Twice/yr
II
6
Total:
33
91
To convert the english units to metric, conversion factors are presented at the beginning of this docunent
Nl: No Information
* This data determined from additional information supplied by Navy activity
~ Actual sludge generation rate is probably much higher
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TABLE 2. NADEP PAINT SPRAY BOOTH SURVEY RESULTS
Sump
Wastewater
Waste
Booth
Nimber of
Paint Booth
Paint Booth
Paint Usage
Paint Curing
Maintenance
Treatment
Generat i
Activity
Dimension
Booths
Type
Duty Cycle
Rate
Method
Schedule
Method
Rate
(ft)
(shi fts/day)
(gal/week)
(druns/yr*b>
Alameda NADEP
6.5x10x7
2
Crossdraft*
1
5
Most aired
Twice/yr
Water & sludge are
4
12.5x14x8
1
Crossdraft*
1
2
Air dried
Once/mo
shipped as haz. waste
13
13x7.5x7
2
Crossdraft*
1
3
Air dried
Twice/yr
Water is sent to IWTP;
2
7x16x8
4
Crossdraft*
1
10
Air dried
Twice/yr
sludge is druimed ft
2
12.5x13x8
1
Crossdraft*
1
10
Aired,baked
Once/yr
shipped as haz. waste
3
9.5x25x6.5
2
Crossdraft*
1
3
Air dried
Once/yr
H
7
5x68x7
1
Crossdraft*
1
30
Air dried
Twice/yr
M
20
5x46x7
1
Crossdraft*
1
30
Air dried
Twice/yr
M
20
15x31.5x15
1
Crossdraft*
1
5-6
Air dried
Once/2 no
M
10
Cherry Point NADEP
10x20x10
2
Crossdraft
2
20
Air dried
Once/wk
Water drained to IWTP;
24
20x10.5x10
1
Downdraft
2
70
Air dried
Once/4 mo
sludge is haz. waste
NI
Jacksonville NADEP
9x12x8
2
Crossdraft
2
NI
NI
Twice/yr
Water is sent to IWTP;
NI
5x8x8
1
Crossdraft
2
Nl
Nl
Twice/yr
sludge is druimed ft
NI
35x15x30
1
Downdraft
2
Nl
NI
Twice/yr
shipped as haz. waste
NI
Norfolk NADEP
7x8x10
1
Crossdraft
1
15+/-
10X Aired
NI
Water is sent to IWTP;
6+/-*
7x8x12
2
Crossdraft
1
15+/-
10X Aired
NI
sludge is druimed ft
6V*
12x8x8
1
Crossdraft
2
20
95X Aired
Once/3 mo
shipped as haz. waste
4
6x8
1
Crossdraft
1
7
Air dried
Once/3 mo
II
1
4x12x20
1
Crossdraft*
2
10
10X Aired
Once/3 mo
II
Nl
7x30x12
1
Crossdraft*
2
10
10X Aired
Once/3 mo
II
Nl
12x14x40
1
Crossdraft*
2
10
10X Aired
Once/3 mo
M
NI
40x75x130
4
Downdraft
2
60-80
Air dried
Once/3 mo
N
32
Pensacola NADEP
8x8x19
1
Downdraft
1
30
Air dried
Nl
Water is sent to IWTP;
6*
8x18x9
1
Downdraft
1
30
Air dried
NI
sludge is druimed ft
6+
4x6x6
1
Crossdraft*
1
30
Air dried
Nl
shipped as haz. waste
1+
9x21x10
1
Crossdraft
1
14
Air dried
Once/6 wks
II
5*
10x24
1
Crossdraft
1
80
Air dried
Once/6 wks
II
6*
8x12x8
1
Crossdraft
1
16
Air dried
Once/6 wks
M
1 +
10x54x10
1
Crossdraft
1
16
Air dried
Once/6 wks
H
6*
10x30x10
1
Crossdraft
1
16
Air dried
Once/6 wks
II
4+
10x15x15
1
Crossdraft
1
75
Air dried
Once/6 wks
M
6*
15x24x15
2
Crossdraft
1
80
Air dried
Once/6 wks
II
6*
50x90X36
1
Downdraft
1
391
Air dried
Once/6 wks
II
10+
San Diego NADEP
14.5x14.5x3 8
Crossdraft
2
3
50X Aired
Nl
Nl
Nl
Total:
54
227
To convert the english units
to metric.
conversion factors
are presented at the beginning of this
docunent
Nl: No information
• This data determined
from additional information supplied by Navy activity
Actual sludge generation rate is probably much higher
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SECTION 3
GUIDELINE CONSTRUCTION WORK PACKAGE
In this section, step by step instructions for converting the water curtain PECS of two
types of paint booths is presented. In subsection 3.1, general issues common to both types of
paint booths are discussed. In subsections 3.2 and 3.3, step-by-step instructions and information
specific to each type of booth are presented.
The two types of water curtain paint spray booths for which retrofit packages are
developed are crossdraft and downdraft. These booths are distinguished by the direction in
which ventilation air flows through them. For each type of booth, general retrofit requirements
are independent of booth size and duty cycle. Thus, construction work packages for these two
types of booths are presented without reference to booth size or operations.
In general, the crossdraft booth is the easiest and least expensive booth to convert. It
is also the most common water curtain booth operated at Navy activities. For this reason,
conversion of the crossdraft type booth is discussed first and perhaps in greater detail than the
downdraft type booth.
The operating and waste disposal permits that are required before installation of the
dry filter system are not discussed in this section, rather they are presented in detail in Sec-
tion 4.
3.1 GENERAL CONVERSION ISSUES AND INSTRUCTIONS
The proper conversion of a paint spray booth must take into consideration general
system issues, such as the characteristics and applicabilities of dry filter systems available on the
market, as well as general design issues, such as the fan size and required dry filter surface
area. These issues and system design elements are addressed in this subsection, and will be
referred to in subsequent discussions in which specific paint booth conversion instructions are
provided.
3.1.1 Dry Filter System Selection
The first step in converting a paint booth PECS from wet to dry operation is to select
the appropriate filtration system. There are many types of dry filter PECSs available on the
market; depending on the situation, some are more applicable than others. In selecting the
appropriate filter system, a number of issues, such as paint booth duty cycles and paint usage
rates, must be considered. However, before these issues are discussed, a brief description of the
various filter types and characteristics is provided. Further information is provided in
Appendix A.
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3.1.1.1 Filter Types and Characteristics
There are four principal types of filters currently used: fiberglass cartridges, multilayer
honeycombed paper rolls or pads, accordion-pleated paper sheets, and cloth rolls or pads.
Qualitative characteristics of each type of filter are summarized in Table 3. The performance
of these filter types is characterized by three basic parameters: particulate capacity, resistance
to air flow, and particulate removal efficiency. Fiberglass cartridge filters are characterized by
low capital equipment and installation costs, reasonable particulate capacities, and high
particulate removal efficiencies. Replacement filters are fairly expensive per square foot, and
the downtime associated with filter replacement is quite high compared to other systems.
Fiberglass cartridge filters are generally installed in crossdraft booths that are used less than one
shift per day.
Multilayer honeycombed paper roll type filters are characterized by moderate
installation costs, fairly high particulate capacities, and moderate to high particulate removal
efficiencies. Replacement costs per square foot are fairly low, and the downtime associated with
their replacement is also low. This type of filter may be used in either light, moderate, or high
production rate booths. The honeycombed paper filters are also available in pads; however,
the downtime associated with pad replacement is fairly high, thus the rolls are recommended.
Cloth filter rolls are characterized by moderate installation costs, high particulate
capacities, and relatively high particulate removal efficiencies. Replacement costs per square
foot are low, and the downtime associated with their replacement is quite low. These types of
filters may be used in either light, moderate, or high production rate booths. The pressure
differential across a clean cloth filter is higher than for the other filter types discussed, therefore
upgrading of the fan motor may be required if this system is installed. The capital outlay for
a replacement motor is generally justified by the savings accrued from the low filter replacement
rate.
TABLE 3. DRY FILTER SYSTEM CHARACTERISTICS
Filter Characteristics
Filter Type
Particulate
Capaci ty
Removal
Efficiency
Cost
Replacement
T ime
Fiberglass Cartridge
Moderate
High
High
High
Honeycombed Paper
High
High
Low
Low
Cloth
High
High
Low
Low
Pleated Paper
Low
Low
High
Low
9
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Accordion pleated paper filters are characterized by low to moderate installation costs
and per square foot replacement costs, moderate capacities, and moderate to low removal
efficiencies. The downtime associated with filter replacement is low, thus they may be used in
virtually any type of paint spray booth. Despite the fact that the particulate removal efficiency
of this type of filter is low, it should adequately control emissions from most Navy paint booths.
For all systems described above, filter replacement is required when the maximum rated
pressure differential across the filter face is reached. This maximum rated pressure differential
is specified by the manufacturer, and varies from system to system. The differential pressure
across the filter should be monitored daily, if not continuously. Filter manufacturers sell
manometers that measure the pressure differential across the filter media.
3.1.1.2 Selection Criteria
The critical paint booth operating parameters that must be considered when selecting
a dry filter system are:
• The paint booth usage rate (i.e the number of shifts per day the booth is used, and
the average amount of time the booth remains inactive).
• The average transfer efficiency of the paint application system (this transfer
efficiency is defined as the pounds of paint applied on the workpiece divided by
the total pounds of paint used, and is generally reported as a percent. It is a
function of the target geometry, the type of coating, and the application method).
• The average quantity of paint used per day.
• The characteristics of the paint used.
• The applicable emission regulations.
The paint booth usage rate should be considered when determining how much downtime
may be tolerated for filter replacement. For example, the throughput rate for a booth used
less than one shift per day will not be affected by the downtime required to replace filters that
take a relatively long time to deploy (such as fiberglass cartridges). However, the throughput
rate for a booth operated two shifts per day may be significantly affected by downtime due to
filter replacement if such a system were installed. In this case, it would be better to install a
cloth or honeycombed paper roll type filter.
The average transfer efficiency and paint usage rate can be combined to determine the
paint overspray rate, which defines the rate at which the particulate capacity of the dry filter is
reached. This, in turn, determines the filter replacement schedule. Filter systems for booths
that are used heavily should have fairly high particulate capacities, (such as the cloth roll filters)
despite the fact that capital and installation costs for such systems may be higher. The equation
used to calculate the filter replacement is:
Paint Usage y . Transfer
Rate (gal/hr) ' Efficiency
-1 Number of square feet of
= filter reaching maximum
capacity per hour
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Paint characteristics are important in determining the compatibility of the paint used
with the dry filter system. For example, the particulate size distribution of the paint overspray
should be matched with the filter media, otherwise surface clogging or insufficient emission
control may result. When the general type of filter system has been selected (i.e., fiberglass
cartridge vs. pleated paper) the manufacturers and vendors should be consulted to determine
which filter of the type selected is optimal. Many manufacturers will perform tests to determine
filter-paint compatibilities, if paint samples are supplied to them.
Emissions regulations must be considered in selecting the appropriate filter system.
Issues pertaining to emissions regulations are discussed in more detail in Section 4, and
Appendix A. Included in Section 4 is a list of names, addresses and phone numbers of the
appropriate regulatory agencies for every NSY and NADEP within the U.S. It is advisable to
refer to the local air pollution regulatory agency to ensure compliance with applicable air
emission requirements.
3.12 General Engineering Design Issues and Instructions
The second step involved in converting a paint booth PECS is to determine the filter
surface area required for adequate ventilation and optimal particulate removal. This is a
function of the required volumetric flowrate through the booth and the design filter face velocity.
The volumetric flowrate through the booth is calculated by multiplying the linear air
flowrate through the booth by the cross-sectional area of the booth perpendicular to the flow.
According to Occupational Safety and Health (OSHA) regulations defined in 29 CFR 1910.94,
the required design linear air flowrate, or velocity, through a paint spray booth upstream of the
object being painted is 100 ft per minute (fpm). For a margin of safety, 125 fpm is generally
used as the design criterion. The converted booth must be designed to accommodate this
flowrate.
The required filter surface area is obtained by dividing the volumetric flowrate by the
design filter face velocity. The design filter face velocity is specified by the manufacturer, and
defines the optimal flowrate at which the filter operates to remove particulate. The design filter
face velocity varies significantly depending on the type of filter, thus the filter system to be
installed must be specified before this calculation is performed.
The next step is to evaluate fan system operation to determine if fan modifications are
required. This is done by summing up the total airflow resistance (in inches of water column
[inches w.c.] at a given volume flowrate) experienced by the forced draft supply fan(s) in the
booth air supply duct(s) and the induced draft fan(s) in the booth exhaust duct(s) Many cross
draft booths have only exhaust fan(s), and do not have air supply fan(s). The airflow resistances
are due to the presence of the loaded paint filters (generally on the order of 0.5 inches w.c. for
all but the cloth type, which ranges from 1 to 2 inches w.c. or more), the exhaust duct work (on
the order of 0.5 inches w.c. or more), the water curtain baffle system, inlet air filters, and any
other flow obstructions.
After the total fan resistance is calculated, the operating efficiency curve of the supply
and exhaust fans currently in place must be consulted to determine whether or not the fan
system is capable of delivering the required volume flowrate (as described above). The fans may
require some alteration to ensure adequate ventilation. Generally, exhaust duct fan systems
require downsizing rather than upgrading, because the flow resistance of a dry filter PECS is
often lower than the flow resistance of a water curtain PECS. This results in a lower electricity
demand after conversion. However, fan downsizing does not necessarily imply fan replacement.
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If it appears a slightly more powerful fan system is required, it is advisable to remove
the baffles located in the exhaust plenum of the water curtain PECS prior to installation of the
new fan system. These baffles are an integral part of the water curtain PECS because they
generate the actual water curtain; however, they contribute a considerable friction loss to the
exhaust flow. If the existing fan capacity is slightly low, the removal of the baffles may be all that
is required to meet ventilation flowrate requirements. Removal of the baffle system requires
more sheet metal work, however. Alternatively, replacement of the fan motor with one of
slightly high horsepower is possible, rather than replacement of the entire fan system.
If the induced draft exhaust fan capacity is too high, and replacement is required,
removal of the baffles may allow the installation of a fan motor having a lower power rating than
would be required if the baffles were not removed. This results in considerable energy savings.
The alternative is to install a damper in the exhaust duct upstream of the exhaust fan. However
this solution results in unnecessarily high energy usage.
To ensure uniform ventilation in a converted crossdraft booth, the filters must be evenly
distributed across the exhaust face. In this way, the air flow through the booth is laminar with
few eddy currents. By replacing a water curtain PECS with an evenly distributed, dry filter
PECS, ventilation through the booth can be improved, because the air flow into a water curtain
PECS is not evenly distributed across the exhaust face.
As with all dry filtration systems, partial blinding of the filter media will occur as the
quantity of overspray collected increases. Blinding will occur in those filter sections in front of
which frequent painting occurs. However, this should not cause any ventilation problems,
provided that these filters are replaced when the maximum design pressure differential across
them is reached.
3.13 Shut down/Access/Lay down Arrangements
Shutdown time will vary depending on the type of filter system installed, the type of
booth being modified, how extensive the required repairs and modifications are, and the
manpower and resources available to carry out the work. For example, a 12 ft by 20 ft booth
may be completely modified in 3 to 5 days, provided that little or no sheetmetal repair work is
required, there is ample draw from the exhaust fan, and the water curtain baffles do not require
removal. However, a 30 ft by 60 ft downdraft facility with significant corrosion damage could
take many weeks to renovate, especially if only three or four people are available to perform the
required modifications.
There is one rule of thumb available to estimate the amount of time the paint booth will
be out of commission. This rule can be applied only if no complications (i.e., fan replacement,
rust damage repair, etc.) exist, and the frame only requires attachment. The installation of the
filter support frame provided by the filter manufacturer is a relatively small operation, and
should average between 8 and 12 hours per 100 ft2 of filter surface area.
Most sections of the booth requiring modification are accessed within the booth. It is
only when excessive corrosion damage to exterior booth walls is present that external access
may become necessary. This issue must be considered on a case-by-case basis.
For crossdraft booths, the inside of the booth should suffice for all laydown require-
ments. The frame supporting the filter system wall may be assembled inside the booth, or may
be delivered to the booth fully assembled at the time that the system is to be installed. For the
conversion of a downdraft booth, a relatively large area near the booth must be identified for
12
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the stockpiling of necessary equipment and material. In addition, a temporary site for the
storage of discarded equipment and materials may be required. After the floor grating is
covered and sealed, the inside of the booth may be used for all laydown arrangements.
32 SPECIFIC INFORMATION AND STEP-BY-STEP INSTRUCTIONS FOR
THE CONVERSION OF A CROSSDRAFT PAINT SPRAY BOOTH
32.1 General Discussion
The primary feature of the crossdraft booth is that fresh ventilation air passes
horizontally through the booth, picking up paint overspray particulate and solvent vapors. The
ventilation air is exhausted through a PECS located along the wall opposite the air intake face.
A crossdraft booth may be entirely enclosed and equipped with intake air dust filters, or it may
be partially enclosed with short sidewalls and a roof section to prevent overspray into adjacent
areas. The retrofit requirements for both types are the same, because the volumetric flowrate
through the PECS before conversion is the same as after conversion.
322 Crossdraft System Conversion Procedures
Step 1: Perform Equipment Audit
Prior to selecting a dry filter system or contacting filter vendors, a complete equipment
audit must be performed to determine booth system characteristics. Information regarding
booth equipment, its condition, and its operating parameters should be obtained in as much
detail as possible. The parameters and items of interest are:
• Booth dimensions.
• Booth manufacturer.
• Booth manufacturer specifications and drawings.
• The current condition and structural integrity of booth (i.e., rust damage and fan
corrosion).
• Exhaust fan manufacturer.
• Exhaust fan selection curves.
• Exhaust fan horsepower and electrical rating (voltage, AC or DC, phase,
amperage, etc.).
• Exhaust fan rating as installed (air flow [in cfm] at what pressure rating [in inches
w.c.]).
• The pressure drop (in inches w.c.) across the existing PECS baffle system, both
with and without the water scrubber system in operation.
• The measured air flow (in cfm) and measured vacuum (in inches of w.c.) just
upstream of the exhaust fan when operating the booth in its present normal mode
(doors closed, water curtain on, etc.).
13
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In addition to the equipment audit, site-specific permit issues should be addressed at
this time. A discussion of the permit processes that must be considered is provided in Section 4.
Step 2: Select the appropriate dry filter system
Filter system options and selection criteria are discussed in Section 3.1 and Appendix A.
After characterizing paint spray booth operations in terms of filter system compatibility, and
reviewing information gathered from the relevant permitting agencies, evaluate the criteria
discussed in Section 3.1, and select the appropriate dry filter system.
Step 3: Select a filter system supplier
After tentatively selecting one of the four filter types, filter system suppliers should be
contacted to discuss merits of each manufacturer's design, installation services, and price. After
selecting a supplier, obtain all performance information concerning the filter brand selected, such
as particulate loading capacities, recommended face velocities, and the pressure differential
across the clean filter.
Many filter manufacturers will perform filter-paint compatibility tests to evaluate
particulate removal efficiencies and filter loading capacities. This service should be used after
tentative selection of the most applicable filter type.
It is a good idea to contact and/or visit paint booths in which the filter media
recommended by the vendor is installed. In this way, filter replacement procedures may be
observed, and the downtime associated with filter replacement can be accurately assessed. In
addition, a site visit affords the opportunity to obtain information regarding advantages and
limitations of the system selected from a source other than the vendor.
Step 4: Design of the retrofit package
After selecting and characterizing the filter system to be installed, the retrofit package
must be designed. The information obtained from the filter system vendor must be combined
with the equipment audit and permit requirement information collected in previous steps to
perform the calculations (for filter surface area and fan sizing) discussed in Section 3.1. Some
of the issues and questions that may arise in evaluating the information and performing the
calculations are:
• What is the condition of the existing booth? Does it require extensive sheetmetal
replacement?
• Is the fan oversized? Can it be easily downsized to reduce operating costs by
installing a smaller motor?
• Is the exhaust fan in good condition, and does it have the capacity for the dry
filter PECS selected?
• Will the existing baffle system need to be removed?
Based on the evaluation and calculation results, the retrofit package containing
equipment lists and explicit directions for the required site modifications must be generated.
The package may contain specification drawings that the vendor will use to supply the filter
frame system, and construction workers (electricians, sheet metal workers, etc) will use to
14
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properly install the system. The package should include any required alterations to the fan
system and the booth structure.
Generalized diagrams of the type that may be included in the retrofit package are
provided in Figures 2 and 3. Figure 2 illustrates a typical crossdraft water curtain paint booth
of unspecified dimensions to be converted. Figure 3 illustrates the same booth retrofit for dry
filter operation.
The retrofit package must include directions for constructing a support frame onto which
the supplier's filter support unit will mount. This support frame is usually a sheetmetal wall,
spanning the booth from wall to wall and from floor to ceiling (although it may not need to be
as high as the ceiling). The sheetmetal wall must have one or more rectangular openings in it.
The manufacturer's filter support unit will attach across the rectangular opening(s).
The directions in the construction work package should indicate the size of each
opening, and attachment points and mounting hardware requirements. It is important to
interface closely with the vendor in designing the filter support system, because the vendor has
considerable experience in constructing easily installed systems having uniform flow.
Step 5: Installation of the dry filter PECS
Before the dry filter system may be installed, the existing booth must be prepared.
Water sumps and piping must be drained, and contaminated water and sludge must be disposed
of in a safe and legal manner. It may be necessary to scrape or sandblast portions of the
structure to remove excessive paint build-up.
It is good practice to remove all existing piping, pumps and drain lines at this time to
prevent their accidental future use. After this general clean-up, the entire booth should be
thoroughly inspected for corrosion and other forms of damage. It is possible that previously
undetected corrosion damage will be found during this inspection. If necessary, the modifica-
tions specified in the retrofit package should be changed to include major repairs to areas
severely damaged by rust. Minor rust and corrosion damaged areas should be cleaned and
treated with a rust preventative, and small pits or holes covered with a patch.
After the inspection and minor repair work are concluded, the major booth alterations
indicated in the specification retrofit package must be performed. These include the
replacement of corroded sections with structural steel or sheet metal, removal of baffle systems,
fan system modifications, and installation of the filter support frame. When fully refurbished,
the external shell of the booth should be as air tight as possible to allow maximum fan and
particulate removal efficiency.
This retrofit work may be performed either by the vendor, an outside contractor, or in-
house labor. If there is significant corrosion damage to the booth or fans, or if fan and/or fan
motor replacement is required, it may be too involved or too costly to have the vendor install
the system, thus contractor or in-house labor may be optimal.
All that remains is to install the dry filter PECS. The dry filter system may be installed
either by the vendor, contractor, or in-house labor. If in-house or contractor labor is to be used,
the filter manufacturer will provide standard installation drawings and instructions for their
product.
15
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3 J SPECIFIC INFORMATION AND STEP-BY-STEP INSTRUCTIONS FOR
THE CONVERSION OF A DOWNDRAFT PAINT SPRAY BOOTH
33.1 General Discussion
Downdraft paint spray booths are generally larger than crossdraft booths (often 1700 ft2
of floor space or more). The primary feature of the downdraft booth is that fresh ventilation
air flows vertically downward through the booth picking up paint overspray particulate and
solvent vapors. Downdraft booths vary significantly from site to site, however the entire floor
surface of the booth is generally a grating through which the ventilation air passes.
The area below the grating is a water sump into which a large portion of the overspray
particulate settles. The ventilation air containing the particulate not deposited in the sump is
drawn through baffled water spray scrubbers located in the side walls of the booth. Paint
particulate is scrubbed from the air, which is then vented outside (note: the scrubber system does
not remove solvent vapors).
In general, downdraft booths are entirely enclosed, with intake air dust filters and supply
fans mounted on the roof. In addition, exhaust fans are often roof-mounted. Conversion of
downdraft booths, while considerably more difficult than crossdraft booths, can be quite cost
effective. Conversion of this type of booth must be considered on a case-by-case basis, but
certain guidelines apply and will be covered in as much detail as possible.
332 Downdraft System Conversion Procedures
Step 1: Perform Equipment Audit
Prior to selecting a dry filter system or contacting filter vendors, a complete equipment
audit must be performed to determine booth system characteristics. Information regarding
booth equipment, its condition, and its operating parameters should be obtained in as much
detail as possible. The parameters and items of interest are:
• Booth dimensions.
• Booth equipment manufacturer.
• Does the booth floor consist of a grating over a sump?
• Booth manufacturer specifications and drawings.
• The location of the baffled water spray scrubber system (i.e., on the side of the
booth), as well as the accessibility of the system (i.e., is it easily accessed and is
it accessed from inside or outside the booth).
• The current condition and structural integrity of the equipment (i.e., rust damage
and fan corrosion).
• Supply and exhaust fan manufacturer.
• Supply and exhaust fan horsepower and electrical rating (voltage, AC or DC,
phase, amperage, etc.).
18
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• Supply and exhaust fan rating as installed (air flow [in cfm] at what pressure rating
[in inches w.c.]).
• Supply and exhaust fan selection curves.
• The pressure drop (in inches w.c.) across the existing PECS baffle system, both
with and without the water scrubber system in operation.
• The measured air flow (in cfm) and measured vacuum (in inches w.c.) just
upstream of the exhaust fan when operating the booth in its present normal mode
(doors closed, water curtain on, etc.).
In addition to the equipment audit, site-specific permit issues should be addressed at
this time. A discussion of the permit processes that must be considered is provided in Section 4.
Step 2: Select the appropriate dry filter system
Filter system options and selection criteria are discussed in Section 3.1 and Appendix A.
After characterizing paint spray booth operations in terms of filter system compatibility, and
reviewing information gathered from the relevant permitting agencies, evaluate the criteria
discussed in Section 3.1, and select the appropriate dry filter system.
Step 3: Select a filter system supplier
After tentatively selecting one of the four filter types, filter system suppliers should be
contacted to discuss merits of each manufacturer's design, installation services, and price. After
selecting a supplier, obtain all performance information concerning the filter brand selected, such
as particulate loading capacities, face velocities, and the pressure differential across the clean
filter. Filter manufacturers will perform filter-paint compatibility tests to evaluate particulate
removal efficiencies and filter loading capacities. This service should be used after tentative
selection of the most applicable filter type.
It is a good idea to contact and/or visit paint booths in which the filter media
recommended by the vendor is installed. In this way, filter replacement procedures may be
observed, and the downtime associated with filter replacement can be accurately assessed. In
addition, a site visit affords the opportunity to obtain information regarding advantages and
limitations of the system selected from a source other than the vendor.
Step 4: Design of the retrofit package
After selecting and characterizing the filter system to be installed, the retrofit package
must be designed. The information obtained from the filter system vendor must be combined
with the equipment audit and permit requirement information collected in previous steps to
perform the calculations (for filter surface area and fan sizing) discussed in Section 3.1. Some
of the issues and questions that may arise in evaluating the information and performing the
calculations are:
• What is the condition of the existing booth and equipment? Is extensive
sheetmetal work required?
• Are the fans oversized? Can they be easily downsized to reduce operating costs
by installing smaller motors?
19
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• Are the supply and exhaust fans in good condition, and do they have the capacities
required for the dry filter PECS selected?
Based on the evaluation and calculation results, the retrofit package containing
equipment lists and explicit directions for the required site modifications must be generated.
The package may contain specification drawings that the vendor will use to supply the filter
frame system, and construction workers (electricians, sheet metal workers, etc.) will use to
properly install the system. The package should include any required alterations to the fan
system and the booth and equipment structures.
Generalized diagrams of the type that may be included in the retrofit package are
provided in Figure 4 and 5. Figure 4 illustrates a typical downdraft water curtain paint booth
of unspecified dimensions to be converted. Figure 5 illustrates the same booth retrofit for dry
filter operation.
Note that the plenum and sump chamber located below the floor grates in Figure 4
have been sealed off in Figure 5 to prevent the possibility of paint booth air escaping into the
chamber. If this area is not sealed off, a stagnant zone under the booth floor will develop in
which solvent laden air may accumulate. This can result in a potentially explosive environment.
The chamber located under the floor grating should be sealed off in the following
manner: steel plates must be welded together over the grating to provide a vapor tight cover
over the existing water sump. The plates will be supported by the grating (which will bear their
full load), thus the steel plates need not be very thick—1/8 inch should suffice. The plates
should extend across the area under the scrubber housings, and be supported from below along
the sides of the booth to provide a floor for the dry filter PECS. The plates installed along the
sides do not support much load other than the PECS, thus 1/8 inch should suffice. Where the
floor plates border walls or equipment, a thorough caulking is advised to prevent the build-up
of solvent vapors.
As illustrated in Figure 5, each exhaust plenum structure has three solid walls that are
joined to the steel plate floor noted above, and are connected to the exhaust duct. The fourth
wall, which faces the booth interior, is actually a door that swings upward in front of the filters
to allow easy access during filter replacement. The door ensures that the flowrate through the
booth is maintained at 100 fpm in the vicinity and well below the breathing zone of the paint
booth operator(s). Furthermore, the filter frame is placed so as to ensure that flow through the
filter system is uniform and unobstructed.
Unlike crossdraft systems (which have few variations), downdraft systems vary
significantly. For example, one type has sumps and grates located only along the sides of the
booth. Retrofitting this type of booth requires that only the side grates be covered with welded
plates and sealed off. Another type of downdraft booth is equipped with water curtain sumps
that are located above ground. For this type of booth, no floor modifications are necessary,
however removal of the sumps is required. Despite the differences in floor systems, most, if not
all downdraft booths may be equipped with a hinged door to facilitate filter replacement.
The retrofit package must include directions for constructing a support frame onto which
the supplier's filter support unit will mount. This support frame is usually a sheetmetal wall,
spanning the length of the booth walls from the floor to the required filter height. The
sheetmetal wall must have rectangular openings in which to attach the manufacturer's filter
support unit.
20
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PLAN
Figure 4. Diagram of a downdraft paint spray booth equipped with a
water curtain PECS.
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The directions in the retrofit construction work package should indicate the size of the
support frame, attachment points and mounting hardware requirements. It is important to
interface closely with the vendor in designing the filter support system, because the vendor has
considerable experience in constructing easily installed systems having uniform flow.
Step 5: Installation of the Dry Filter PECS
Before the dry filter system may be installed, the existing booth must be prepared.
Water sumps and piping must be drained and contaminated water and sludge must be disposed
of in a safe and legal manner. It may be necessary to scrape or sandblast portions of the
structure to remove excessive paint build-up. It is good practice to remove all existing piping,
pumps and drain lines at this time to prevent their accidental future use.
After this general clean-up, the entire booth, scrubber housing and ductwork should be
thoroughly inspected for corrosion and other forms of damage. It is possible that previously
undetected corrosion damage will be found during this inspection. If necessary, the modifica-
tions specified in the retrofit package should be changed to include major repairs to areas
severely damaged by rust.
After this inspection, a decision should be made as to whether portions of the existing
baffle and spray scrubber housing can be utilized in the construction of the new system. In
addition, all piping, pumps, electrical equipment and water curtain baffles must be removed from
the housings. If portions of the existing housings do not fit into the new design, or if they are
damaged beyond repair, they must be removed and disposed of. If existing housings are to be
reused, minor rust and corrosion damaged areas should be cleaned and treated with a rust
preventative, and small pits or holes covered with a patch. Large corroded areas, or areas
severely damaged, should be removed and replaced with new structural steel or sheetmetal.
After the inspection and minor repair work are concluded, the major booth alterations
as indicated in the specification retrofit package must be performed. These include the filter
housing structure retrofit and repair, fan system modifications, installation of the welded floor,
and installation of the filter support frame. When fully refurbished, the external shell of the
filter housing should be as air tight as possible to allow maximum fan and particulate removal
efficiencv.
This work may be performed either by the vendor, an outside contractor, or in-house
labor. If there is significant corrosion damage to the filter housing or fans, or if fan and/or fan
motor replacement is required, it may be too involved or too costly to have the vendor install
the system, thus contractor or in-house labor may be optimal.
All that remains is to install the dry filter PECS. The dry filter system may be installed
either by the vendor, contractor, or in-house labor. If in-house or contractor labor is to be used,
the filter manufacturer will provide standard installation drawings and instructions for their
product.
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SECTION 4
PERMITTING PROCESSES
There are several permits from local, state and federal agencies that may be required
prior to paint booth modification. The types of permits generally required concern air emissions
from the booth, building, fire and safety codes, and waste disposal regulations. Each of these
topics are discussed fully in this section.
4.1 AIR EMISSIONS REGULATORY AGENCY PERMIT PROCEDURES AND
INFORMATION
4.1.1 Permitting Procedures
In general, when a paint booth is modified in some way, a modification permit or
permission to construct the modifications must be obtained from the appropriate air emissions
regulatory agency. However, permitting processes for paint spray booth modifications vary
significantly from state to state, as well as district to district.
For example, in the State of Hawaii, paint spraying operations that utilize an enclosed
paint booth are exempt from the air pollution permit system (provided that the booth is not
part of a major stationary source, or subject to Federal New Source Performance Standards
[NSPS]). Thus, a permit may not required for the modifications outlined in this Users Guide,
although the State of Hawaii Department of Health should be informed. However, paint booth
operators in the Los Angeles area are required to submit a Permit to Construct application, as
well as a Spray Booth Summary form to operate a modified paint booth.
It is the responsibility of the Navy activity to contact the appropriate regulatory agency,
and determine whether or not a modification permit is required. A list of appropriate regulatory
agencies is provided in the following subsection.
Whenever a paint booth modification is being considered, it is best to inform the
appropriate regulatory agency well in advance of any modifications. In addition, if a permit
application is required, it should be submitted and approval obtained before modifications are
installed. Generally, operating permits for modified spray booths need only be obtained from
one air emissions regulatory agency, thus multiple permits from local, state and federal agencies
are not required.
The primary concern of the regulatory agency issuing the modification permit is whether
or not the modifications will cause an increase in particulate or organic air emissions. The
particulate removal efficiencies of dry filter PECSs are as high or higher than those for water
curtain systems. Furthermore, neither system is capable of controlling VOC emissions. Thus,
24
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it is important to stress on the application that the proposed paint booth modifications will not
result in an increase in emissions from the booth.
The information presented in this section is based on the assumption that the paint
booth targeted for modification is already permitted for operation with a water curtain PECS,
thus only a permit for modification is required. This distinction is critical, because if the booth
is not permitted (and the regulatory agency does not know of its existence), then considerable
effort may be required to obtain an operating permit.
If the booth requires an operating permit from the appropriate air emissions regulatory
agency, but does not yet have one, it is advisable to terminate booth operations, and contact the
agency immediately. The booth operator will probably be allowed to complete the modifications
prior to submitting an operations permit application. Please note, this statement is applicable
only to booth operators that have not yet obtained a required operating permit from an air
emissions regulatory agency. In regard to unpermitted booths, be aware of the fact that many
regulatory agencies require that all painting (and probably booth modification) activities cease
in unpermitted booths until operating permits have been obtained.
The information requested in modification permit applications is generally concerned
with the location of the paint booth, the quantity of paint used per day, the VOC content of the
paint used, the workpieces to be coated, the type of PECS in place, etc. The information
supplied on the modification permit application should be the same as the information supplied
in the original permit application already on file at the agency, with the exception of the PECS
modification.
The focus of this section is only on permitting processes involved with converting PECSs
from wet to dry operation. Some air emission regulatory agencies currently consider requiring
the use of best available control technologies (BACT) to control VOC emissions from paint
booths. This action is generally being considered as applicable to new sources (i.e. nonpermitted
paint booths), and booth modifications that result in an increase in VOC emissions. Fortunately,
the conversion of PECSs from wet to dry operation does not fall into this category. The status
of permitted booths may change in the future. This Users Guide does not address permitting
issues and procedures involved in complying with BACT requirements for the control of VOC
emissions. Such an analysis is extremely complicated and out of the scope of this project.
4.12 Air Emissions Regulatory Agency Information for NSYs and NADEPs Located in the
United States
The appropriate regulatory agencies that should be contacted for procedural advice
and permit applications are given in this section for all the NSYs and NADEPs in the United
States. The addresses and telephone numbers included in this section are valid as of
September 1, 1989.
In general, the staff members of these agencies are easily contacted for advice and
information by telephone or in writing. This service should be taken advantage of for a variety
of reasons. For example, the permit process can be greatly simplified by knowing all the factors
and requirements involved. In addition, if it is perceived by the regulating agency that the
facility requesting the permit is willingly giving information, the agency may be more inclined
to expedite the permit application process.
25
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Military Activity
Air Emissions Regulatory Agency
Pearl Harbor NSY
Pearl Harbor, HI
State of Hawaii
Department of Health
Environmental Permits Branch
P.O. Box 3378
Honolulu, HI 96801
(808) 548-6410
Alameda NADEP
Alameda, CA
Mare Island NSY
Mare Island, CA
Bay Area Air Quality Management District
939 Ellis Street
San Francisco, CA 94109
(415) 771-6000
Long Beach NSY
Long Beach, CA
South Coast Air Quality Management District
9150 Flair Drive
El Monte, CA 91731
(818) 572-6200
North Island NADEP
San Diego, CA
San Diego County
Air Pollution Control District
9150 Chesapeake Dr
San Diego, CA 92123-1095
(619) 694-3307
Puget Sound NSY
Bremerton, WA
Puget Sound Air Pollution Control Agency
200 West Mercer Street, Room 205
Seattle WA 98119
(206) 296-7330
Pensacola NADEP
Pensacola, FL
State of Florida
Department of Environmental Regulation
Northwest District
160 Governmental Center
Pensacola, FL 32501-5794
(904) 436-8300
Jacksonville NADEP
Jacksonville, FL
Bio-Environmental Services Division
Dept. of Air & Water Pollution Control
421 West Church Street, Suite 412
Jacksonville, FL 32202
(904) 630-3210
26
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Cherry Point NADEP Department of Natural Resources
Cherry Point, NC Division of Environmental Management
1424 Carolina Avenue
Farish Building
Washington, NC 27889
(919) 946-6481
Charleston NSY Department of Air Pollution Control
Charleston, SC Trident District
2470 Air Park Road
North Charleston, SC 29418
(803) 554-5533
Norfolk NSY
Norfolk, VA
Norfolk NADEP
Norfolk, VA
Department of Air Pollution Control
Region 6
2010 Old Greenbriar Road, Suite A
Chesapeake, VA 23320-2168
(804) 424-6707
Philadelphia NSY Department of Environmental Resources
Philadelphia PA Bureau of Air Quality Control
1875 New Hope Street
Norristown, PA 19401
(215) 270-1920
Portsmouth NSY Department of Environmental Protection
Kitterey, ME Bureau of Air Quality Control
State House, Station 17
Augusta, ME 04333
(207) 289-2437
4.1 J Paint Booth Modification Permit Application Processes in
Two Target Areas
Paint booth modification permit application processes vary significantly across the
country. Because it is not feasible to evaluate the permit application process for every NSY and
NADEP activity, two representative areas have been selected for in-depth evaluation. The two
areas selected are: Long Beach, CA, which is under the jurisdiction of the South Coast Air
Quality Management District (SCAQMD), and Norfolk VA, which is under the jurisdiction of
Region VI of the Commonwealth of Virginia, State Air Pollution Control Board (SAPCB).
Descriptions of the permit procedures required in these two areas, as well as copies of the
required permit applications, are provided.
Case 1: SCAQMD Paint Booth Modification Permit Procedures
The Los Angeles area was selected because it has one of the most stringent permitting
processes in the country. For modifications of paint booths that are already permitted to
operate in the Los Angeles Area, the SCAQMD requires that Form 400A (Application for
27
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Permit to Construct) be submitted. In addition, supplemental information requested in Form
400-C-l (Paint Booth Summary) must be included with Form 400A. Instructions for the
completion of Form 400A is provided in Form 400B. Copies of these forms are provided in
Figures 6 through 11.
A $250.00 filing fee must be included with each application. In addition, a permit
evaluation fee will be levied on the permit requestor. The fee amount varies, and normally
depends on the electric power capacity (hp) of the fans in the converted system. Normally, the
electrical capacity of the water pumps would be included in this calculation, however the water
pumps will not be present in the converted system.
In addition to these forms, the SCAQMD requires that modification plans, specifications
and drawings be submitted in duplicate. Equipment location drawings are required that indicate
property locations related to streets and adjacent properties, exhaust stack locations and
discharge directions. In addition, paint booth locations on the property must be indicated, as
well as their relationships to all adjacent buildings and parking lots within 300 feet not located
on the property.
Detailed booth drawings are also required in which booth dimensions, size and shapes
of booth openings, and sizes and locations of booth vents and fans are indicated. Detailed
information concerning the air pollution control equipment must also be furnished. Structural
design calculations and details are not required. If standard equipment is installed, the
manufacturers catalog describing the air pollution control equipment may be submitted to fulfill
this requirement.
It should be noted that most or all of the information requested should have already
been supplied to the SCAQMD to obtain the original operating permit. Thus, assuming that the
paint booth operator has a copy of the original permit application, most of the work required
to complete the application has been done. The only additional effort involves updating the
PECS description and facility diagrams.
The SCAQMD evaluates permit applications for paint booth modifications based on
compliance with Rule 481. This rule stipulates:
(a) A person shall not use or operate any spray painting or spray coating equipment
unless one of the following conditions is met:
(1) The spray coating equipment is used inside a controlled enclosure which is
approved by the Executive Officer. Any control enclosure for which an
application for permit for new construction, alteration, or change of
ownership or location is submitted after the date of adoption of this rule shall
be exhausted only through filters at a design face velocity not less than 100 ft
per minute nor greater than 300 ft per minute, or through a water wash
system designed to be equally effective for the purposes of air pollution
control.
(2) Coatings are applied with electrostatic and/or airless spray equipment.
(3) A method of application or control is used which has an effectiveness equal
to or greater than the equipment specified in subsection (a)(1) or (a)(2) of
this rule.
Section (b) discusses painting operations that are exempt from this rule. Navy painting
operations do not come under any of the listed categories.
28
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SOUTH COAST AIR QUALITY MANAGEMENT DISTRICT
9150 Flair Drive El Monte, CA 91731
APPLICATION FOR PERMITTO CONSTRUCT AND PERMIT TO OPERATE AND EXCAVATE AND
FOR PLANS REQUIRED BY THE EXECUTIVE OFFICER
CO.ID.
IF YOU HAvt AS EXISTING PERMIT ENTER
'0 NJM0E*- f NO PERMIT BLANK
FOR FEE INFORMATION AND SMALL BUSINESS EXEMPTION
SEE REVERSE SIDE
PLEASE TYPE Oft PAINT
SCAQMD USE
SEC
TS
10 NUMBER (FOR NEW CO ONLY!
, A PERM'T *0 BE :SSUEO TO
BUSINESS LICENSE NAME Of ORGANIZATION THAI IS TO RECEIVE PERMIT
NAME lOR NAMES) Of OWNER OR PRINCIPAL PARTNERS 00>*ONS
8 TYPE Of ORGANIZATION
CORPORATION
j PARTNERSHIP
INDIVIDUAL OWNER
LOCAL GOV T AGENCY
STAT? AGENCY
FEDERAL AGENCY
UTILITY
9 ESTIMATED COS* Oc rQ-i^VcN-: OP ALTERATION
BASIC EQjiP^ENT •
AJR POLLUTION
CONTROL EOUlPMEN'• .
1C fOR T-= Ntvv CONSTRUCTION ALTERA'ICN. TRANSFER Oc OWNERSHIP OR LOCATION. WHAT IS
EST1MA*ED START NG OATE' ESTIMATED COMPLETION DATE5
GENERAL NATTjRt Of 6USINESS
12 PRINCIPAL PROD JCT
13 DO YOU C.AIM COSfiDENTiAjTY Of OATA?
YES C NO 0
|C YES S'ATS NATjCE 0= -ATA ON SEPARATE SHEET
14 NORMAL OPERATING HOURS
Of SUBJECT EQUIPMENT
15 HAS A CEQA DOCUMENT BEEN PREPARED FOR
THIS PROJECT? YES D NO D
r»Av^ aa^Cit
Mfe**./YFAB
15A ARE ALL COMPANIES FACILITIES IN CAUfORNIA
tN COMPLIANCE WITH AIR POLLU'lON RULES'
YES ~ NOD
ie SIGNATURE Oc Re SPONSIBLE MEMBER Of ORGANIZATION
17 OfftClAL TITLE Of SlGNE R
19 "YPEO On PRINTED NAME Oc S'GNER
EQUIP CAT NO
APPLICATION NO
TYPE
BORC
WORK UNfTS ASSIGNMENT
AyC P/0 UNfT ENGR
CHECK OR MONEY ORDER NUMBER
I III IV.
PRIOR VERSIONS NOT VAUD {Counted o« R«v»n
SEE REVERSE FOR FEES REQUIRED UPON FILING
Figure 6. SCAQMD Paint Spray Booth Permit Form 400A (Front).
29
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SOUTH COAST AIR QUALITY MANAGEMENT DISTRICT
Filing Fees
Except as noted following, a S250 filing fee must accompany each application for Permit to Construct/Operate
1 For small businesses the filing fee is S160 The small business declaration form below must be completed in order to be
considered a small business
2 Each application, for change of ownership requires a S110 transfer fee.
3. All applicants, including state, local governmental and public districts, must pay a permit evaluation fee. Such fees are in
addition to filing fees and change of ownership fees.
SEE APPLICATION INSTRUCTIONS FORM 400-B FOR ADDITIONAL INSTRUCTIONS
Call (8181 572-6212 for assistance
SUPPLEMENTAL DATA FORMS REQUIRED
Special supplemental data forms must be completed for BOILERS, LIQUID HEATERS. DEGREASERS. DRV CLEANING
EQUIPMENT, OVENS. SPRAY BOOTHS. STORAGE TANKS. ABRASIVE BLASTING OPERATION and PRINTING and DRYING
SYSTEM
MAKE CHECK PAYABLE TO "SOUTH COAST AQMD"
MAIL APPLICATION TO SOUTH COAST AQMD
91 50 Flair Drive
El Monte. CA 91731
SMALL BUSINESS DECLARATION
Inordertobeconsideredasmallbusinessas specified in Regulation XIII, this form must be completed. If not e small business,
do not complete this form
A "Small Business" is a business which is independently owned and operated and meets the following criteria, or if affiliated
with another concern, the combined activities of both concerns shall meet these criteria:
The number of employees is 10 or less; and
the total gross annual receipts are $500,000 00 or less
I hereby certify, under penalty of perjury, that the business enterprise containing the emission source(S)for which an SCAQMD
Permit to Construct or Permit to Operate is being applied herein qualifies as a SMALL BUSINESS based on compliance with the
def.nn.cn above
Signature of Applicant Date Telephone Number
Printed or Typed Signature Company Name
State law requires that we inform you about the Office of Permit Assistance The Office of Permit Assistance is a state agency which <6 available to assist you
anc prov>ae information relating to the perrmi approval process at the state and local level Call {916)322-4245 for information.
83359 0- Revised 5/89
Figure 7. SCAQMD Paint Spray Booth Permit Form 400A (Back).
30
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SOUTH COAST AIR QUALITY MANAGEMENT DISTRICT
SPRAY BOOTH SUMMARY
(SEE OTHER SIDE FOR INSTRUCTIONS)
ONE COPY OF THIS FORM MUST BE FILLED OUT COMPLETELY FOR EACH BOOTH
AND MUST ACCOMPANY THE APPLICATION FOR PERMIT. FORM 400-A.
1 BUSINESS LICENSE NAME OF CORPORATION. COMPANY. INDIVIDUAL OWNER OR GOVERNMENTAL AGENCY UNDER WHICH APPLICATION (FORM 400-A) IS
SUBMITTED
2 BOOTH MANUFACTURER. MOOEL NUMBER & SERIAL NUMBER (SEE ITtM 2 ON REVERSE SIDEl
3 BOOTH TYPE AND OUTSIDE DIMENSIONS
CONVEYORIZED YES D NO ~
AUTOMOTIVE D
WIDTH X
BENCH D
LENGTH X
4 EXHAUST FAN OATA
MANUFACTURER
. NO OF FANS .
. FAN DIAMETER-
NO OF FAN BLADES .
5 EXHAUST CONTROL
EXHAUST FILTERS D
WATERWASH O
no of filters
PUMP HP
SIZE OF EACH FILTER
PUMP CAPACITY IN GALLONS/MiN_
OTHER Q
MANOMETER OR DRAFT GAUGE INSTAU.EC YES
»~
6 Plant location
RESIDENTIAL ~ RESIDENTIAL • COMMERCIAL D
DISTANCE OF EXHAUS' TO PROPERTY UNE
COMMERCIAL C COMMERCIAL • INDUSTRIAL CD
FT.
? ARTiCLE SPRAYED
AUTOMOB'LE D
METAL
~
PLASTIC I
WOOO I
OTHER I
6 METHOD OF APPLICATION aO AIR ATOMIZATlON b 0 PRESSURE ATOMlZATION (AIRLESS) C O COMBINED AIR AND AIRLESS
d CD HVLP (HIGH VQJJME LOW-PRESSURE) e ELECTROSTATIC 1 D AUTOMATIC 2 D AIR 3 C DISC 4. CD MANUAL
5 CD AiRLESS f D OTHER
9 OPPOSITION OF SPRAYED ITEMS
AIR DRIED D OVEN DRIED OR BAKED C
LENGTH of T.VE in M.NUTES BETWEEN COAT.NG AND BAKING
MAX TIME MIN TIME
AVG TIME .
10 IOENTIFY All COATINGS ANO SOLVENTS APPLIED IN THIS BOOTH
VOlATILE ORGANIC COMPOUNDS
(VOC). LB/GAw OR GRAM/UTER
AVG AMOUNT USED IN ONE
DAY. GALLONS
•TYPE OF COATING ANO SOLVENT
ENAMEL
LACQUER
STAIN
HI SOLID
water borne
POWDER
ADDED THINNER
Clean-up solvent
SURFACE PREPARATION SOlUTiON
OTHER
MAXIMUM AMOUNT OF COATlNGSiS} USED IN THIS EQUIPMENT IN ANY ONE DAY= GALLONS
MAXIMUM AMOUNT OF CLEAN-UP SOLVENT USED IN THIS EQUIPMENT IN ANY ONE DAY= GALLONS
• MATERIAL SAFETY OATA SHEETS (MSDS) FOR All COATINGS AND SOLVENTS MUST BE INCLUDED MSDS MUST INCLUDE PERCENTAGES OF ALL
COMPONENTS IN THE COATlNG(S).
SIGNATURE OF
RESPONSIBLE
PERSON
NAME
TITLE
fQRM 4O0 • C-1
Figure 8. SCAQMD Paint Spray Booth Permit Form 400-C-l (Front).
31
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SOUTH COAST AIR QUALITY MANAGEMENT DISTRICT
APPLICATION INSTRUCTIONS FOR SPRAY BOOTHS
FILL OUT REVERSE SIDE AND RETURN WITH YOUR APPLICATION. FORM 400-A
The proper filing fee, as indicated on Form 400-A. Application For Permit To Construct and Permit To Operate, must
accompany each application. Checks or money orders should be made payable to the South Coast Air Quality Management
District
With each application for permit to construct and permit to operate any type of spray booth, the following data, specifications,
plans and drawings must be submitted:
1 EQUIPMENT LOCATION DRAWING. The drawing or sketch submitted must be to scale (suggested scale: 1 inch = 100
feet; accuracy of measurements to the nearest 5 feet will be satisfactory) and must show at least the following
a The property involved and outlines and heights of all buildings on it. Identify property lines plainly,
b Location and identification of the spray booth on the property, showing vent or stack.
c Location of the property with respect to streets and all adjacent properties Identify adjacent properties Show
location of all buildings and automobile parking lots outside the property that are within 350 feet of the booth
Identify all such buildings (as residence, apartment house, machine shop, warehouse, etc.), specifying height of
each building (number of stories). Identity parking lots. Indicate direction (north) on the drawing Show booth stack
and indicate direction of discharge
2. DRAWING OF BOOTH. (See NOTE below ) Supply an assembly drawing, dimensioned and to scale, in plan, elevation and
as many sections as are needed to show clearly the following:
a Over-all width, height and length of the booth
b Size and shape of openings or doors
c Size and location of vents and fan.
d Details of any additional air pollution control device. Show as many detail drawings as are needed to indicate clearly
how the control device operates, showing particularly the path of the air through the control section If water is used,
state the amount of water sprayed (gallons per minute), number of spray heads and the amount of chemical additive
used m the water (if any), naming the chemical used
3 Composition of all coatings and thinners used must be provided in sufficient detail to show the status of this booth
relative to Rule 442. It is the applicant's responsibility to supply this information with the application for authority to
construct and permit to operate or insure that it is submitted by the coatings and thinner suppliers directly to the Air
Quality Management District In either case, assurance is g.ven t^at the information will remain confidential
4. STACK/EXHAUST EMISSIONS DATA
a Mass emissions rate and stack concenration of air pollutants
b Stack diameter
c Stack height above ground level
d. Exhaust temperature
e Exhaust velocity
f Exhaust flow rate (volumetric)
g Buildings whose wakes may affect the pijmes of the stack
h Dimensions of the buildings identified above
i Maximum concentration of air pollutants for any averaging times of concern and any receptors of concern
NOTE: Structural design calculations and details are not required When standard commercial equipment is to be
installed, the manufacturer's catalog describing the equipment may be submitted m lieu of the parts of Item 2 that it
covers All information required above that the catalog does not contain must be submitted by the applicant
ADDITIONAL INFORM A TION MA Y BE REQUIRED
After permit to construct or to install is granted for any equipment, deviations from the approved plans are not
permissible without first securing additional approval for the changes from the Engineering Division
Further information or clarification concerning permits can be obtained by writing or calling the Permit Application
Receiving Unit Headquarters: 91 50 Flair Drive, El Monte, CA 91731, (818) 572-6212; or Colton: 1280 Cooley Drive,
Suite C. Colton. CA 92324. (714) 877-4677
Form 400-C-1 (Continued on reverse side) 11 /88
Figure 9. SCAQMD Paint Spray Booth Permit Form 400-C-l (Back).
32
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SOUTH COAST AIR QUALITY MANAGEMENT DISTRICT
GENERAL INFORMATION FOR FORM 400-A
APPLICATION FOR PERMITTO CONSTRUCT AND PERMIT TO OPERATE
A Use one application Form 400-A for each permit unit of basic equipment and one application Form 400-A for each
permit unit of air pollution control equipment. Call (818) 572-6212 for assistance
B Except as noted following, every applicant filing for a permit shall pay a filing fee of $250 for each application
1. The filing fee for small businesses is S160 for each application In order to be considered a small business, the
"Small Business Declaration" must be completed on the reverse of application Form 400-A
2 The filing fee for change of ownership is S110 for each application filed when there has been no change in
operation and a permit to operate had previously been granted and has not otherwise expired. Applications by the
new owner should be submitted before the date of transfer of the equipment
3. All applicants including Federal, State, local governmental agencies and public districts must pay an Engineering
Analysis Fee for equipment requiring a permit to construct or operate.
C. If an application for a permit is canceled, the filing fee shall not be refunded nor applied to any subsequent application,
unless it is determined that such application is not required pursuant to District Rules
D. Permit fees will be determined by the District in accordance with Rule 301 1 and 301.2 These fees shall be paid by the
applicant within 30 days of notification or the permit will be canceled.
E. Every application must be signed by a responsible member of the organization that is to operate the equipment. Each
application must be filled out completely.
F. File application (1 copy) with filing fee and one copy of plans at District headquarters
South Coast AQMD
9150 Flair Drive
El Monte, CA 91731
INCOMPLETE APPLICATIONS ARE NOT ACCEPTABLE
G. The Permit Processing Engineer may require more information to complete his evaluation.
H. A copy of SCAQMD Rules and Regulations or notice of any proposal to adopt or amend a rule or regulation may be
obtained from:
Office of Public Advisor
South Coast AQMD
(818) 572-6283
SUPPLEMENTAL DATA FORMS REQUIRED
Special supplemental data forms must be completed for: BOILERS. LIQUID HEATERS. DEGREASERS, DRY CLEANING
EQUIPMENT, OVENS, SPRAY BOOTHS, STORAGE TANKS. ABRASIVE BLASTING OPERATION and PRINTING and
DRYING SYSTEM
MAKE CHECK PAYABLE TO "SOUTH COAST AQMD"
Forrrt«00-B '©» «»C«rpU from Byl«» and Ciri 1/89
Figure 10. SCAQMD Paint Spray Booth Permit Form 400B (Front).
33
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EXCERPTS FROM RULES AND REGULATIONS
RULE 201. Permit to Construct. A person shall not build, erect, install, alter or replace any equipment, the use of
which may cause the issuance of air contaminants or the use of which may eliminate, reduce or control the issuance of air
contaminants without first obtaining written authorization for such construction from the Executive Officer. A permit to
construct shall remain in effect until the permit to operate the equipment for which the application was filed is granted or
denied, or the application is cancelled
RULE 202 Temporary Permit to Operate.
/aI New Equipment • A person shall notify the Executive Officer before operating or using equipment granted a permit
to construct Upon such notification, the permit to construct shall serve as a temporary permit for operation of the
equipment until the permit is granted or denied. The equipment shall not be operated contrary to the conditions specified in
the permit to construct.
(b) Altered Equipment - The permit to construct granted to modify equipment having a valid permit to operate shall
serve as a temporary permit for operation of the equipment until a new permit to operate is granted or denied The altered
equipment shall not be operated contrary to the conditions specified in the permit to construct A person must notify the
Executive Officer when construction of the modification has been completed.
(c) Existing Equipment - When an application for permit to operate is filed for existing equipment, the application
shall serve as a temporary permit for operation of the equipment. If the equipment was previously operated under permit
and has not been altered, it shall not be operated under a temporary permit contrary to the conditions specified in the
previous permit to operate.
RULE 203. Permit to Operate. A person shall not operate or use any equipment, the use of which may cause the
issuance of air contaminants or the use of which may reduce or control the issuance of air contaminants, without first
obtaining a written permit from the Executive Officer or except as provided in Rule 202 The equipment shall not be
operated contrary to the conditions specified in the permit to operate.
RULE 204. Permit Conditions. To assure compliance with all applicable regulations, the Executive Officer may
impose written conditions on any permit. Commencing work or operation under such a permit shall be deemed acceptance
of all the conditions so specified
RULE 205. Cancellation of Applications. An application, for a permit snail be cancelled and a permit to construct shall
exp re two years from the date of filing of the application unless an extension of time has been approved by the Executive
Officer
RULE 212. Standards (or Approving Permits.
(a) The Executive Officer shall deny a permit to construct or permit to operate, except as provided in Rule 204, unless
the applicant snows that the equipment, the use of which may cause the issuance of air contaminants, or the use of which
may eliminate, reduce or control the issuance of air contaminants, is so designed, controlled, or equipped with such air
pollution equipment that it may be expected to operate without emitting air contaminants in violation of Sections 41 700 or
41 701 o' the State Health and Safety Code or of these rules.
(b) If the Executive Officer finds that the equipment has not been constructed in accordance with the permit and
provides less effective air pollution control than the equipment specififed in tne permit to construct, he shall deny the
permit to operate
Figure U. SCAQMD Paint Spray Booth Permit Form 400B (Back).
34
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After the permit application has been submitted, the District will evaluate the request
in reference to applicable sections of SCAQMD Regulations II (permits), IV (prohibitions), IX
(standards of performance for new stationary sources), X (national emissions standards for
hazardous air pollutants), and XIII (new source review).
Based on the above discussion, any of the three modification analyses presented in
Section 5 should be acceptable to the SCAQMD, thereby making the permit evaluation process
straightforward. The completed permit application, filing fee, and required drawings should be
mailed to the address listed in Section 4.1.2.
Case 2: Virginia SAPCB Paint Booth Modification Permit Procedures
The Commonwealth of VA Department of Air Pollution Control, Region VI was
selected for evaluation because there are two large Navy activities located in this region. This
Region has very specific laws regarding the modification of paint spray booths, which depend
primarily on when the booth was installed.
Paint booths that were in existence before 1972 should already be registered with the
control agency, and require neither an operating permit, nor a modification permit. However,
a registration update will be required before any modifications are made to the booth.
Paint booths that were installed during or after 1972 should already have an operating
permit. In order to modify such a booth, a modification to the permit must be made.
If the booth is not permitted, and the control agency is not aware that the booth exists,
the agency should be notified immediately, and a permit application should be submitted. A
permit may or may not be required, depending on the size of the operation.
Applications for registration updates and permit modifications require that State Air
Pollution Control Board (SAPCB) Form 7, section E-l and E-3, be completed and submitted to
the Regional Office of the Department of Air Pollution Control. Copies of Form 7, Section E-l
and form 7, Section E-2 are provided in Figures 12 through 17, respectively.
42 HEALTH, SAFETY AND BUILDING PERMITS
The following is a listing of facility permits (in addition to those required by air
pollution control and waste disposal agencies) that are usually required by city, county and/or
special district agencies:
• Building Permit
• Fire Permit
• Plumbing Permit
• Electrical Permit
• Health and Safety Permit
In most areas, the local Building Department will issue a single permit package which
will cover building, fire, plumbing, electrical, and health and safety permits. This agency is in
35
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rs)
COMMON WEALTH of VIRQINIA
state air pollution CONTROL BOARD
SECTION M GENERAL INFORMATION
Raaton for Ragntration
G gantir
O 0>v*9« of Owm»f|*ip
Or Location
C Ptrmii Application O Raqnirmon
Na*» Sowrca UPOait
O Permit Application G Otftar ISpocN)
Modification
fot ApenCV Ijti Qrily
0«ll R«Ciiv*0
AtCI'vaO dv
Ragintr Sowca as
AciAOwaoogamani Sant; Data
3v
SIC Cmi;
Plant Ragtitration Numfttr:
UTM Cooromacti:
rm.n i i i u.n
County
Cry:
CriO Numo»'
HHQHt ADOo* MSL I'll
nj
S-c: -¦ .
C Si"" 0'«'_!g_
I < 2
1 t 2
Company »no 0><"i'on Mama
Oati ot Swomiita'
Mailing AQorttl
County
N«m©#r ot gmpiovaai at S«t>
City or Town
Suti
Zip Cmi
Prooanv -*'•» *i S.n
Ptrton to Contact on A>r Ponunon Marian
Tula
T«i«pnona Ngmwr
E*tct Scwrcj Location, .nciwoi nam* of locality (County or City)
MaiOf Activity ai Souroa Location
CI Manufacturing O Hoafrul or Laboratory
G Ratait or Somali Stora G War«fio«*»a
O Qifica Suitomg Q ftt«oani>at or Apia.
O Scnoot or Oturctt CD Othar
Oo Yon Han®« or OiacrtafQt any of tm Fpjtov»ar or Camfiae Company 0"'Ctai
SqnjtW'«
Data
SAPC8 Po"*» 7 'SaCtiO* I 1—P«q« )|
iP»« mv
Figure 12. Commonwealth of Virginia SAPCB Form 7(Section E.l Pgl).
36
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COMMONWEALTH OF VIRGINIA
S'ltt Air Pollution Control Board
SECTION E-I GENERAL information ICant.)
Pertpo Competing Pom*
I 0«t«
Rf^utrition Numof
Uit th« Products Manufactured and/or S«n»»c*« Ptflormad at Thi| facility.
Lot tn« Standard mouitrni Oaui'icjtio* IS'CI Codn 'or Your Op»fanon.
tP TwiS FORM IS BEING USEO BY A NEW OR MOO«f IEO SOURCE AS AN APPLICATION fOR A PERMIT TO CONSTRUCT ANO/O* MOCifY Af.T.
OPERATE.PLEASE COMPLETE THE SECTION BELOW ANO E l. PAGES 3.4 md S If APPLICABLE ANO OTHER REQUIREO SECTIONS.
'¦JRSUANT TO THE PROVISIONS OP THE REGULATIONS FOR THE CONTROL ANO ABATEMENT OF AIR POLLUTION OF THE COMMON
WEALTH Qt VIRGINIA. APPLICATION
-------
COMMONWEALTH OF VIRGINIA
State Air Pollution Control Board
SECTION £ 3 PROCESSING ANO MANUFACTURING OPERATIONS
Company Name
Company Address
Registration Number
Facility Operating Schedule
Hnurt/nay Day«A/V^<>b W»pkf/Y*.«r
Information For Calendar Year
19
Person Completing Form
Dale
Reference
Number
Process or Operation Name
Maximum Rated
Capacity*
Tons/Hour
Normal Feed Input
Number of
Normal Product Output
Ton* / Hour
Toni / Year
Emission
Points into
Air
Tons / Hour
Tons / Yeer
* If Unitt Other Than Tona Are Uied, Specify Units.
SAPC8 Form 7 (Section E-J-Pagi 1)
(Rev. 8/731
Figure 14. Commonwealth or Virginia SAPCB Form 7(Section EJ Pgl).
-------
COMMONWEALTH OF VIRGINIA
State Air Pollution Control BoJ'd
SECTION E 3 PROCESSING AND MANUFACTURING OPERATIONS
Period Completing Form
Registration Number
Reference
Number
Slack or Exhaust Data
Stack
Height
Feet
inside
Eml
Diameter
Feet
Exit Gas
Velocity
Feel/Minute
Exit Gat
Volume
Exit Gat
Temperature
Oegrees F
Air Pollution Control Equipment
Manufacturer and Model Number
Type
(Use Codes
l*>
Collection Efficiency
Design
U>
SO
•• ACFM ¦ Actual Cubic Feet per Minute
1 * Air Pollution Control Equipment Identification Codes
SAPCB Form 7 (Section E 3-page 2)
(Rev. 8/78)
1. Settling Chamber
2. Cyclone
3. Multicv clone
4. Cyclone Scrubber
5. Orifice Scrubber
6. Mechanical Scrubber
7. Ventufi Scrubber
8. Mist Eliminator
9. Electrostatic Precipitator
10. 8aghouse (Fabric Filter)
For Wet Scrubbers, List Gallons per Minute Water Flow and
Inches Water Pressure Drop Across Scrubber, If Known.
11. Catalytic Afterburner
I?. Oirector Flame Afterburner
13. Packed Tower
14. Carbon Adsorption
15. Refrigerant Condenser
16. Refrigerated Liquid Scrubber
99. Other (Specify)
Figure 15. Commonwealth of Virginia SAPCB Form 7(Scction EJ
-------
COMMONWEALTH OF VIRGINIA
State Air Pollution Control Board
SECTION E 3 PROCESSING AND MANUFACTURING OPERATIONS
Emisnon Rate*
Reference
(List Emusiont in Ton* par Year and Pounds per Hour and Identify Unitt)
Bm>i of Emitsion
Eit
Carbon Monoxide
Volatile
Organic Compound!
Nitrogen Oxidai
Porton Completing Form
Registration Numbtff
Figure 16.
Commonwealth of Virginia SAPCB Form 7(Section E3 Pg3).
-------
COMMONWEALTH OF VIRGINIA
State Air PaMuiton Contiot Board
SECTION E 3 PROCESSING AND MANUFACTURING OPERATIONS
Pe»4on Com^iat'nj Form
Reg'tlr.Uion Number
% of Annual Throughput by Sfraion
Normal Oper.itio^ Schedule
(FOR AGENCY USE ONLY)
Reference
Number
December
February
Mar. i
May
June
August
$ept*mbt»r
Nov-»inb
-------
a position to advise the design engineer regarding applicable regulations with which the retrofit
design must comply.
Most local building departments utilize standard, nationally accepted codes such as the
Uniform Building Code, Uniform Plumbing Code, National Fire Code, National Electric Code,
etc. However, in some areas, state or local codes may be used. It is therefore important to
obtain information pertaining to relevant building codes before the design package is completed.
43 DISPOSAL OF SPENT FILTER MEDIA
43.1 General Requirements
Requirements for disposing of the spent filter media vary from state to state. However,
if the paint collected on the filter media is thoroughly dry when removed for disposal (i.e. the
solvents have volatilized off the filter), it is very likely that the filter waste is nonhazardous, and
may therefore be disposed of at a municipal landfill. The results of the paint booth survey
indicate that virtually all paints used in Navy paint booths are air dried. Thus, the waste filters
from these booths are probably thoroughly dry. Prior to disposal, the spent filter media should
remain in the paint booth until it is dry to the touch.
Each Navy activity has the responsibility of determining whether or not state or local
laws permit disposal of spent filter media at municipal landfills. In addition, permission to
dispose of the spent filters may also be required from the municipal landfill that accepts the
waste.
When requesting permission to dispose of the filter waste from the relevant state or
local agency, it is imperative that the agency personnel understand that no solvents remain on
the filter, and no solvent vapors are emitted from the filter. Thus, they should not present a
flammability or ground water contamination problem. Once this has been established with the
waste disposal facility and/or regulatory agency, permission for disposal at a municipal landfill
should be easily attained.
432 Filter Waste Disposal Information For NSYs and NADEPs Located
Across the United States
The appropriate regulatory agencies that may be contacted for procedural advice
concerning disposal of spent filter waste are given in this section for all the NADEPs and NSYs in
the United States. The addresses and telephone numbers included in this section are valid as of
September 1, 1989.
In general, the staff members of these agencies may easily be contacted for advice and
information by telephone or in writing. This service should be taken advantage of for a variety of
reasons. For example, the disposal process can be greatly facilitated by knowing all the factors and
requirements involved.
42
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Navy Activity
Waste Disposal Regulatory Agency
Pearl Harbor NSY
Pearl Harbor, HI
City and County of Honolulu
Department of Public Works, Refuse Division
Chief of Engineering
650 South King Street
Honolulu, HI 96813
(808) 523-4775
Alameda NADEP
Alameda, CA
Mare Island NSY
Mare Island, CA
Long Beach NSY
Long Beach, CA
North Island NADEP
San Diego, CA
State of California
Department of Health Services
Alternate Technologies Section
Toxic Substances Control Division
714/744 P Street
P.O. Box 942732
Sacramento, CA 94234-7320
(916) 322-3670
Pensacola NADEP
Pensacola, FL
Jacksonville NADEP
Jacksonville, FL
Department of Environmental Regulation
Environmental Administration of
Hazardous Waste Regulations
Twin Towers Office Building
2600 Blair Stone Road
Tallahassee, FL 32399-2400
(904) 488-0300
Cherry Point NADEP
Cherry Point, NC
Division of Health Services
Solid and Hazardous Waste Management Branch
Department of Solid Waste
P.O. Box 2091
Raleigh, NC 27602
(919) 733-0692
Puget Sound NSY
Bremerton, WA
Department of Ecology
Solid and Hazardous Waste Program
NW Regional Office
4350 150 Avenue NE
Redmond, WA 98052
(206) 867-7053
43
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Portsmouth NSY Department of Environmental Protection
Kitterey, ME Bureau of Oil and Hazardous Materials
State House, Station 17
Augusta, ME 04333
(207) 289-2651
State of New Hampshire
Department of Environmental Services
Hazardous Waste Management Division
6 Hazen Drive
Concord, NH 03301-6509
(603) 271-2942
Philadelphia NSY Department of Environmental Resources
Philadelphia PA Bureau of Waste Management
P.O. Box 2063
Harrisburg, PA 17120
(717) 787-7382
Norfolk NSY
Norfolk, VA
Norfolk NADEP
Norfolk, VA
Department of Waste Management
Monroe Building, 11th Floor
101 N. 14 Street
Richmond, VA 23219
(804) 225-2667
Charleston NSY Bureau of Solid and Hazardous
Charleston, SC Waste Management
2600 Bull Street
Columbia, SC 29201
(803) 734-5200
4 .33 Filter Waste Disposal Processes in Three Target Areas
It is out of the scope of this project to determine the laws pertaining to waste
classification for every NSY and NADEP activity, thus three states have been selected for a review
of their waste disposal policies regarding spent filter media. The states selected are California,
Virginia, and Florida.
Case 1: California Waste Disposal Regulations
The State of California Department of Health Services policy regarding the disposal of
spent filters is the same as that used for the disposal of empty paint cans. The paint can disposal
policy requires that the cans be drained so that only a thin, completely dry film of paint remains.
In addition, the cans must not emit toxic or ignitible vapors, nor be mixed with any other hazardous
materials. If these conditions are met, the paint cans are classified as nonhazardous waste.
Accordingly, if the spent filters are completely dry before disposal, and they do not emit
toxic or ignitable vapors, they are classified as nonhazardous waste in the State of California. As
44
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such, they may be disposed of at a municipal landfill, with the approval of the State Regional Water
Quality Control Board.
Information was obtained from the State Regional Water Quality Control Board
pertaining to spent filter disposal requirements in the Los Angeles area. Information from the Los
Angeles Region IV office (which has jurisdiction over Los Angeles and Ventura Counties) was
obtained. "Hie Region IV office allows waste that is classified as nonhazardous by the Department
of Health Services (DOHS) to be landfilled without need for prior approval. However, the
particular landfill that takes the waste may require that a letter be obtained by the waste generator
from the water quality control board certifying that the waste may be landfilled.
In some regions of California, the local air quality control agency requires that municipal
landfills be monitored for VOC emissions. Landfills in these areas may therefore be hesitant to
permit disposal of the spent filters at their facility. When petitioning the landfill facility to accept
the filter wastes, it is important to stress that the filters are thoroughly dry and therefore do not
emit any VOCs or toxic compounds into the atmosphere.
Case 2: Virginia Waste Disposal Regulations
The Commonwealth of Virginia Department of Waste Management does not consider
filter waste generated in painting operations as hazardous, if and only if the filters are dry, and are
not emitting VOC vapors. Thus, such filters may be disposed of at a municipal landfill. The
primary objective of this requirement is to prevent the disposal of flammable waste in the municipal
landfill.
The commonwealth of Virginia requires that, prior to disposing of dry filter waste in a
permitted municipal solid waste landfill, the landfill receive written permission from the Executive
Director to accept this waste from the generator. This requirement is in accordance with Part VIII
of the Virginia Solid Waste Management Regulations. Before the approval is received, some
testing of the waste filters may be required. If testing is required, an environmental contractor
should be contacted to collect and analyze a waste filter sample for leachable hazardous metals, as
well as solvent vapor emissions.
The leachability (or EP toxicity) test may be required for filter waste containing toxic
metals such as lead or chrome. However, it is very unlikely that toxic metals leach out of Navy
paint booth filter waste, because the coatings used in Navy operations are specially formulated for
stability and long life, even under extreme conditions. Furthermore, if the filters are thoroughly
dry before they are disposed of, solvent vapor emissions from them should be negligible. For these
reasons, any required test results will probably be negative, which would result in the waste filters
being classified as nonhazardous.
Case 3: Florida Waste Disposal Regulations
The State of Florida Department of Environmental Regulations stipulates that some
analytical testing of representative filter waste samples be performed before the waste is classified
as nonhazardous. The tests required focus on the leachability and ignitibility characteristics of the
filter waste. For reasons discussed above, the test results will probably be negative, thereby allowing
the waste filters to be classified as nonhazardous.
45
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SECTION 5
COST/BENEFIT ANALYSIS
To perform an accurate cost/benefit analysis of a particular process, the process under
consideration must be well defined and characterized. In addition to the information collected
during the design of the construction work package, a cost/benefit analysis of the conversion
must consider a number of operating procedures, such as:
• The quantity of hazardous waste generated annually
• The percentage of paints used that are air dried
• The paint overspray rate
• The wastewater treatment system
These parameters are important in evaluating the costs and benefits of PECS conversion because
they define the installation and operating costs associated with the booth before and after
conversion.
A general description of the economic analysis performed in this Section is provided in
Subsection 5.1. The analysis was conducted according to procedures outlined in the Naval
Facilities Engineering Command P-442 Economic Analysis Handbook (NAVFAC P-442). All
costs reported in Section 5 are in the format specified in the NAVFAC P-442 document.
In Section 5.2, costs incurred in converting a water curtain PECS to dry filter operation
and operating costs associated with both water curtain and dry filter systems, are presented.
These costs are itemized and described in detail. In addition, system reliability, availability, and
maintainability are discussed.
w-
Section 5.3 provides examples of how the information presented in Sections 5.1 and 5.2
is used to perform an economic evaluation of the paint spray booth conversion option. In this
section, sample economic evaluations of the conversion option for three different paint spray
booths are presented. The booth characteristics assumed in these examples were selected based
on the Navy paint booth survey results, and represent all practical sizes and types of Navy booths
currently in use.
5.1 ECONOMIC ANALYSIS TECHNIQUES
The techniques used in the economic evaluation of converting a Navy paint spray booth
PECS from wet to dry operation were drawn from the NAVFAC P-442 document. The three
steps outlined in NAVFAC P-442 that are involved in performing an economic evaluation are:
(1) the identification and quantification of all one-time and recurring costs in constant and
46
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present value dollars, and the development of a cash flow diagram for each alternative; (2)
calculation of the savings to investment ratio (SIR); and (3) determination of the discounted
payback period. Each of these steps is discussed in general terms for the benefit of readers
outside the Navy.
5.1.1 Identification and Estimation of all Costs
The initial step in performing an economic analysis of any proposed system alteration
is the identification of all costs, both one-time and recurring, for both the present and proposed
systems. The only one-time cost considered in this Users Guide is for the replacement of the
water curtain PECS with a dry filter system. The recurring costs considered are: waste treatment
and disposal, filter media replacement, utilities, and labor.
After the costs have been identified, the constant dollar value of the costs must be
assessed. This information is used to generate cash flow diagrams for both the present system
and the proposed conversion.
After completion of the cash flow diagrams, the net present value (NPV) of the
recurring operating and maintenance (O&M) costs for both the current and proposed system
are then determined over the economic life of the paint booth. For the purposes of this Users
Guide, an economic life of 10 years is assumed. This results in a more conservative estimate,
because dry filter PECs will last longer than water-certain PECs, which often require
replacement or significant repair within 10 years.
To estimate the NPV of the recurring costs, some assumptions must be made regarding
cost escalations due to inflation and other factors. In general, if the anticipated rise in O&M
costs is the same as the general inflation rate (assumed to be 5 percent), a 10 percent discount
factor may be applied to calculate the NPV. This is the rate applied to all costs presented in
this Users Guide, with the exception of wastewater and sludge disposal costs.
Future wastewater and sludge disposal costs will not vary at the same rate as inflation.
Thus, an adjusted escalation rate calculation was performed to determine the NPV of wastewater
and sludge disposal costs over the requisite 10-year economic life. This calculation was
performed according to the NAVFAC P-442 document procedures, and is discussed in greater
detail in Section 5.2.
5.1.2 Calculation of the Savings to Investment Ratio
The second step in comparing the economics of a proposed system alteration is to
calculate the savings to investment ratio (SIR), which is defined as the amount of savings
accrued by each dollar of investment. It is mathematically defined as:
Net Present Value (Savings)
Net Present Value (Investment)
The NPV (savings) is obtained by subtracting the NPV of the recurring costs for the
proposed system from the NPV of the recurring costs for the current system. As discussed
above, these costs are calculated over the economic life of the installation. The NPV (savings)
is the total amount of money (in present value dollars) that will be saved if the proposed system
47
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is installed. The NPV (investment) is the total one-time costs incurred to install the proposed
system in present value dollars. For the proposed alternative to be cost-effective, the SIR must
be greater than 1.
5.13 Determination of the Discounted Payback Period
The final step in performing an economic evaluation is to determine the discounted
payback period, which is the time required to accrue sufficient present value savings to offset
the investment cost. The discounted payback period is determined by calculating the accrued
year by year savings, and comparing this result to the initial investment in present value dollars.
The point at which the two are equal defines the payback period. For all of the analyses
presented in this section, Table C in Appendix C of the NAVFAC-P442 document was used to
determine the discounted payback period.
52 IDENTIFICATION AND ESTIMATION OF PECS CONVERSION COSTS
As described previously, the only one-time cost considered in this economic evaluation
is the cost incurred to install the dry filter system. The NPV of recurring costs for waste
disposal, filter media replacement, utilities, and labor have been tabulated over the 10-year
economic life of the booth. These one-time and recurring costs are presented and discussed
separately in this section, and are referred to frequently in Section 5.3.
5.2.1 Retrofit System Installation Cost
The dry filter system installation costs can only be evaluated after all the preliminary
efforts (such as the equipment audit and selection of a general filter type) on the construction
work package are complete. At that time, estimates of installation costs (such as fan downsizing
or replacement, sheetmetal repair, and filter frame acquisition and installation) can be derived
using Table 4. Please note that many of the costs presented in Table 4 are the same for
downdraft and crossdraft systems. The exception is the floor grate modification cost, which is
applicable only to downdraft systems.
TABLE 4. CAPITAL AND INSTALLATION COSTS OF CONVERTING WATER CURTAIN
PECS'S TO DRY FILTER OPERATION
Construction Item
Cost in Current Dollars
Fan replacement:
(0-5,000 cfm)
(5,000-15,000 cfm)
(15,000-20,000 cfm)
(20,000-25,000 cfm)
(5,000-15,000 cfm)
Fan Motor Replacement:
(0-1 HP)
Additional HP (ea)
Major Sheetmetal Repair
Minor Sheetmetal Repair
Grate floor covering
Cartridge Filter Frame
Paper Filter Frame
Cloth Filter Frame
Pleated Filter Frame
$15.74/sq. ft.
$8.80/sq. ft.
S22.32/sq. ft.
$9.76/sq. ft.
$9.47/sq. ft.
$10.38/sq. ft.
$7.31/sq. ft.
SI80/1,000 cfm
$100/1,000 cfm
$80/1,000 cfm
$68/1,000 cfm
$60/1,000 cfm.
$300
$20
48
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The costs provided in Table 4 are in present value dollars, and may be considered valid
through 1990. In addition, due to the large number of filter system manufacturers, the filter
frame costs listed in Table 4 are approximate.
522 Water Curtain And Dry Filter System Operating Costs
The operating costs for both the dry filter and water curtain systems have been tabulated
in present value dollars over the economic life of the booth according to the description given
in 5.1.1. For the constant dollar value (which is necessary to develop a cash flow diagram), refer
to the costs reported for 1989. The operating costs have been divided into five categories:
replacement filter costs, filter waste disposal costs, wastewater and sludge disposal costs, utility
costs, and labor costs.
Replacement Filter Costs
The filter replacement costs associated with the honeycombed paper, cloth, pleated
paper, and fiberglass cartridge type filters are presented in Tables 5, 6, 7, and 8, respectively.
The costs presented in each of these tables were derived in the following manner:
• A transfer efficiency of 30 percent was assumed
• Values for the filter capacity and cost per square foot (in current dollars) were
obtained from the filter manufacturer
• A range of paint usage rates from 5 gallons per day to 50 gallons per day was
selected based on the survey results
• The estimated transfer efficiency is multiplied by the applicable usage rate and
divided by the filter capacity to obtain the number of square feet of filter that
reaches the maximum capacity limit per day. (Note, this value does not imply that
a certain square footage of filter requires replacement per day, rather it is a tool
for calculating filter depletion rates).
• The depletion rate (square feet per day) is then multiplied by the cost per square
foot to obtain the cost per day incurred due to filter depletion
• To determine the frequency of filter replacement, simply divide the filter surface
area (obtained by following the procedures outlined in Section 3) by the depletion
rate to determine the number of days between filter replacement
If the actual paint usage rate for a given booth is not represented in the range presented
in the tables, the filter replacement costs may be interpolated between the paint usage rates that
most closely match the actual usage rate. In addition, the time unit specified for the paint
usage rates in Tables 5 through 8 (days) may be changed to months or weeks, however, the
replacement costs will also reflect this change. For example, for a paint usage rate of 50 gal per
week, the present value cloth filler replacement costs for 1989 will be $28.00 per week.
Filter Disposal Costs
Because nearly all the paints used by the Navy are air dried coatings, the spent filters
are also air dried and should not emit solvent vapors upon removal from the booth. It is
49
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TABLE 5. PRESENT VALUE OF HONEYCOMBED PAPER FILTER REPLACEMENT
COST OVER THE 10 YEAR ECONOMIC LIFE OF THE PAINT BOOTH
a
Present Value Filter Replacment Costs ($/day)
Paint Usage Rates
Year
5 gal/day
10 gal/day
20 gal/day
30 gal/day
40 gal/day
50 gal/day
1989
$3.25
$6.50
$13.00
$19.50
$26.00
$32.50
1990
12.95
$5.91
$11.82
$17.73
$23.63
$29.54
1991
$2.69
$5.37
$10.74
$16.11
$21.48
$26.85
1992
$2.44
$4.88
$9.76
$14.65
$19.53
$24.41
1993
$2.22
$4.44
$8.88
$13.31
$17.75
$22.19
1994
$2.02
$4.03
$8.07
$12.10
$16.14
$20.17
1995
$1.83
$3.67
$7.33
$11.00
$14.67
$18.33
1996
$1.67
$3.33
$6.67
$10.00
$13.33
$16.67
1997
$1.51
$3.03
$6.06
$9.09
$12.12
$15.15
1998
$1.38
$2.75
$5.51
$8.26
$11.02
$13.77
1999
$1.25
$2.50
$5.01
$7.51
$10.01
$12.52
Total
$23.21
$46.42
$92.84
$139
$186
$232
a: Assuming a base cost of
$.26/sq. ft.
and a transfer efficiency of 30%
TABLE 6. PRESENT VALUE OF CLOTH ROLL FILTER REPLACEMENT COST OVER
THE 10 YEAR ECONOMIC LIFE OF THE PAINT BOOTH
a
Present Value Filter Replacment Costs ($/day)
Paint Usage Rates
Year
5 gal/day
10 gal/day
20 gal/day
30 gal/day
40 gal/day
50 gal/dc
1989
$2.80
$5.60
$11.20
$16.80
$22.40
$28.00
1990
$2.55
$5.09
$10.18
$15.27
$20.36
$25.45
1991
$2.31
$4.63
$9.25
$13.88
$18.51
$23.14
1992
$2.10
$4.21
$8.41
$12.62
$16.82
$21.03
1993
$1.91
$3.82
$7.65
$11.47
$15.29
$19.12
1994
$1.74
$3.48
$6.95
$10.43
$13.90
$17.38
1995
$1.58
$3.16
$6.32
$9.48
$12.64
$15.80
1996
$1.44
$2.87
$5.74
$8.62
$11.49
$14.36
1997
$1.31
$2.61
$5.22
$7.83
$10.44
$13.05
1998
$1.19
$2.37
$4.75
$7.12
$9.49
$11.86
1999
$1.08
$2.16
$4.31
$6.47
$8.63
$10.78
Total
$20.00
$39.99
$79.99
$120
$160
$200
a: Assigning a base cost of $.28/sq. ft. and a transfer efficiency of 30%
50
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TABLE 7. PRESENT VALUE OF PLEATED PAPER FILTER REPLACEMENT COST
OVER THE 10 YEAR ECONOMIC LIFE OF THE PAINT BOOTH
a
Present Value Filter Replacment Costs ($/day)
Paint Usage Rates
Year
5 gal/day
10 gal/day
20 gal/day
30 gal/day
40 gal/day
50 gal/day
1989
$14.67
$29.33
$58.67
$88.00
$117.33
$146.67
1990
$13.33
$26.66
$53.33
$79.99
$106.66
$133.32
1991
$12.12
$24.24
$48.48
$72.71
$96.95
$121.19
1992
$11.02
$22.03
$44.06
$66.10
$88.13
$110.16
1993
$10.01
$20.03
$40.05
$60.08
$80.11
$100.14
1994
$9.10
$18.20
$36.41
$54.61
$72.82
$91.02
1995
$8.27
$16.55
$33.10
$49.64
$66.19
$82.74
1996
$7.52
$15.04
$30.08
$45.13
$60.17
$75.21
1997
$6.84
$13.67
$27.35
$41.02
$54.69
$68.37
1998
$6.21
$12.43
$24.86
$37.29
$49.72
$62.15
1999
$5.65
$11.30
$22.60
$33.89
$45.19
$56.49
Total
$105
$209
$419
$628
$838
$1,047
a: Assuming a base cost of $.88/sq. ft. and a transfer efficiency of 30%
TABLE 8. PRESENT VALUE OF FIBERGLASS CARTRIDGE FILTER REPLACEMENT
COST OVER THE 10 YEAR ECONOMIC LIFE OF THE PAINT BOOTH
a
Present Value Filter Replacment Costs ($/day)
Paint Usage Rates
Year
5 gal/day
10 gal/day
20 gal/day
30 gal/day
40 gal/day
50 gal/day
1989
$5.08
$10.16
$20.32
$30.48
$40.65
$50.81
1990
$4.62
$9.24
$18.47
$27.71
$36.95
$46.18
1991
$4.20
$8.40
$16.79
$25.19
$33.58
$41.98
1992
$3.82
$7.63
$15.26
$22.90
$30.53
$38.16
1993
$3.47
$6.94
$13.88
$20.81
$27.75
$34.69
1994
$3.15
$6.31
$12.61
$18.92
$25.22
$31.53
1995
$2.87
$5.73
$11.46
$17.20
$22.93
$28.66
1996
$2.61
$5.21
$10.42
$15.63
$20.84
$26.05
1997
$2.37
$4.74
$9.47
$14.21
$18.95
$23.68
1998
$2.15
$4.31
$a.6i
$12.92
$17.22
$21.53
1999
$1.96
$3.91
$7.83
$11.74
$15.65
$19.57
Total
$36.28
$72.57
$145
$218
$290
$363
a: Assuming a base cost of $.45/sq. ft. and a transfer efficiency of 30%
51
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therefore assumed that the filters may be disposed of at a municipal landfill, and the costs
associated with their disposal are negligible.
Waste Disposal Costs
The waste disposal costs associated with a particular water curtain system depend on
a number of variables such as the waste treatment method (if any) and the type of waste
disposed of. These parameters are not mutually exclusive. Navy activities that have access to
municipal or onsite industrial wastewater treatment plants (IWTPs) often drain the supernatant
wastewater to the IWTP, where it is treated at negligible cost. The sludge collected on the
bottom of the sump is periodically removed and disposed of as hazardous waste at considerable
cost.
Navy activities that do not have access to an IWTP generally dispose of the entire
contents of the sump (the wastewater and the sludge) as hazardous waste. The presence of
significant quantities of water in the waste reduces the density and, to some extent, the disposal
cost per volume. However, the total volume of waste generated is very high.
The waste disposal costs per 55 gallon drum are presented in Table 9. These values
are tabulated in present value dollars for each type of waste described above. To calculate the
disposal costs per year, the user should multiply the number of drums generated per year by the
waste disposal costs for the particular type of waste generated.
The costs presented in Table 9 were calculated in a manner slightly different from the
other costs reported in this section. The costs were calculated based on a 0 percent inflation
rate for disposal services over the next four years, and a standard 5 percent inflation rate over
the remaining 6 years. These estimates may seem extremely optimistic; however they were
obtained through conversations with waste disposal company marketing strategists. Increasing
competition and improved disposal techniques were cited as reasons for the near-term price
stabilization. Information from marketing strategists regarding future prices is generally not
forthcoming, and this information may be questionable. However, by assuming the zero percent
escalation rate over the next four years, the costs estimated are made more conservative. A
differential cost escalation rate calculation was performed according to NAVFAC P-442
procedures to obtain the costs presented in Table 9.
TABLE 9. SLUDGE AND/OR WASTEWATER DISPOSAL COSTS
Present Value
Waste Disposal Costs (S/drun)
Year Liquid & Sludge Sludge Only
1989
1990
1991
1992
1993
1994
1995
1996
1997
1998
$200
$182
$165
$150
$143
$137
$131
$125
$119
$114
$300
$273
$248
$225
$215
$205
$196
$187
$179
$170
Total $1,466
$2,199
52
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Utility Operating Costs
The utility costs associated with operating water pumps (for water curtain systems) and
exhaust fans (for both types of PECSs) are presented here. TTie costs of replacement water for
the water curtain system cannot be calculated accurately, because booth operators "top off' the
sumps weekly, if not daily. Thus, water consumption rates cannot be accurately quantified. At
any rate, the cost of replacement water is considered negligible.
The daily operating costs for a water pump or exhaust fan of a particular rated
horsepower are presented in Table 10. Note that these costs are broken down for industrial
and commercial users, because electricity costs for industrial users are generally much lower than
for commercial users. The Table 10 base year costs per kWhr assumed for the industrial and
commercial users are $0,045 and $0,067, respectively. The costs reported are per 8-hour shift,
thus if the booth is operated 2 shifts per day, the dollars reported in Table 10 should be doubled.
After preliminary work on the construction work package is complete, the information
pertaining to the exhaust fan and water pump power ratings is combined with the information
presented in Table 10 to calculate annual electrical operating costs before conversion. Electrical
operating cost estimates of the converted system are also obtained from this table.
Labor Costs
The labor costs associated with maintaining dry filter and water curtain PECSs are
presented and discussed here separately.
The labor costs per square foot to replace the spent filter media depend primarily on
the type of filter employed. For example, as discussed in Section 3, fiberglass cartridge filters
require much more time to replace than most other filter types. The labor costs for filter
replacement are tabulated in Table 11. These costs were obtained by multiplying the
replacement time for each filter type (in hours per 100 ft2) by a labor rate of $17.00 per hour.
The replacement time for each type of filter was obtained from manufacturer estimates, and
assumes easy access to the filter face. The $17.00/hr labor rate was calculated assuming an
hourly wage of $9.00 (typical for a wage grade [WG] level 3 employee in the San Francisco area
in 1989), and an overhead and G&A load of 90 percent. This loading may appear low; however,
the work is performed at a government facility, thus the overhead contribution is small.
The labor costs involved in draining and maintaining water curtain PECSs are presented
in Table 12. Note that the maintenance requirements for the crossdraft and downdraft booths
are very different; downdraft system maintenance is more involved, because it includes removing
the grate and cleaning out somewhat inaccessible parts of the sump system. In addition, the
grate itself requires periodic cleaning and occasional sand blasting to remove the accumulated
overspray particulate. Crossdraft sump maintenance procedures are more straightforward.
In Table 12, the sump clean out costs are presented per drum of waste produced, and
the grate cleaning costs are presented per square foot of floor surface. Actual labor costs for
sump maintenance can be calculated by multiplying the number of waste drums generated in the
cleaning process by the cost per drum to fill. The labor rate used in Table 12 is the same as
that used in Table 11.
The numbers presented in Table 12 were derived for removing sludge accumulated at
the bottom of the sump, and are based on the assumption that the wastewater from the sump
53
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Year
1989
1990
1991
1992
1993
1994
1995
1996
1997
1998
1999
Total
TABLE 10. ELECTRICAL OPERATING COSTS AS A FUNCTION OF HORSEPOWER
Present Value Electrical Operating Cost Per Shift ($/day)
5 HP
10
HP
15
HP
20 HP
30
HP
40
HP
Industrial
Conmercial
Industrial
Conmercial
Industrial
Commercial
Industrial
Commercial
Industrial Conmercial
Industrial Conmercial
User
User
User
User
User
User
User
User
User
User
User
User
$1.35
$2.01
$2.70
$4.02
$4.05
$6.03
$5.40
$8.04
$8.09
$12.07
$10.79
$16.09
$1.23
$1.83
$2.45
$3.66
$3.68
$5.48
$4.90
$7.31
$7.36
$10.97
$9.81
$14.63
$1.11
$1.66
$2.23
$3.32
$3.34
$4.99
$4.46
$6.65
$6.69
$9.97
$8.92
$13.29
$1.01
$1.51
$2.03
$3.02
$3.04
$4.53
$4.05
$6.04
$6.08
$9.06
$8.10
$12.08
$0.92
$1.37
$1.84
$2.75
$2.76
$4.12
$3.68
$5.49
$5.53
$8.24
$7.37
$10.99
$0.84
$1.25
$1.67
$2.50
$2.51
$3.74
$3.35
$4.99
$5.02
$7.49
$6.70
$9.99
$0.76
$1.13
$1.52
$2.27
$2.28
$3.40
$3.04
$4.54
$4.57
$6.81
$6.09
$9.08
$0.69
$1.03
$1.38
$2.06
$2.07
$3.09
$2.77
$4.13
$4.15
$6.19
$5.53
$8.25
$0.63
$0.94
$1.26
$1.87
$1.89
$2.81
$2.51
$3.75
$3.77
$5.62
$5.03
$7.50
$0.57
$0.85
$1.14
$1.70
$1.71
$2.56
$2.29
$3.41
$3.43
$5.11
$4.57
$6.82
$0.52
$0.77
$1.04
$1.55
$1.56
$2.32
$2.08
$3.10
$3.12
$4.65
$4.16
$6.20
$9.63
$14.36
$19.26
$28.73
$28.90
$43.09
$38.53
$57.45
$57.79
$86.18
$77.06
$115
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TABLE 11. LABOR COSTS ASSOCIATED WITH FILTER REPLACEMENT
Present Value Labor Costs For Replacing
Dry Filter Media (dollars/square foot)
Honeycombed
Non-Woven
Pleated
Cartridge
Paper
Cloth
Paper
Year
FiIters
FiIters
FiIters
FiIters
1989
$0,071
$0,054
$0,065
$0,034
1990
$0,064
$0,049
$0,059
$0,031
1991
$0,059
$0,045
$0,053
$0,028
1992
$0,053
$0,041
$0,049
$0,026
1993
$0,048
$0,037
$0,044
$0,023
1994
$0,044
$0,034
$0,040
$0,021
1995
$0,040
$0,031
$0,036
$0,019
1996
$0,036
$0,028
$0,033
$0,017
1997
$0,033
$0,025
$0,030
$0,016
1998
$0,030
$0,023
$0,027
$0,014
1999
$0,027
$0,021
$0,025
$0,013
Total
$0,506
$0,389
$0,461
$0,243
TABLE 12. LABOR COSTS ASSOCIATED WITH SUMP SYSTEM MAINTENANCE
Present Value Sump Maintenance
Labor Costs (Sludge Removal Only)
Downdraft
Crossdraft
Sump
Grates
Sunp
Year
($/drun)
($/sq ft)
($/drum)
1989
$51.00
$0.85
$34.00
1990
$46.36
$0.77
$30.91
1991
$42.14
$0.70
$28.09
1992
$38.31
$0.64
$25.54
1993
$34.82
$0.58
$23.21
1994
$31.65
$0.53
$21.10
1995
$28.77
$0.48
$19.18
1996
$26.15
$0.44
$17.44
1997
$23.77
$0.40
$15.85
1998
$21.61
$0.36
$14.41
1999
$19.64
$0.33
$13.10
Total
$364
$6.07
$243
55
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is treated at an IWTP. This is because little or no labor is required to drain the water from the
sump.
No attempt has been made to estimate the cost impacts of having the booth remain idle
during system maintenance. These costs are a function of the number of painters affected (who
are essentially out of work during that time), workpiece throughput, and system accessibility.
In some cases, this may not be a real cost, because the painters may be utilized for cleaning out
the sump, or they may be transferred to other booths, along with the pieces that would normally
be painted in the booth undergoing maintenance.
5.23 System Reliability, Availability, and Maintainability
The dry filter systems discussed in this document have low failure rates if properly
planned, installed, and operated. Failure is defined here as the inability of the system to
adequately control particulate emissions while simultaneously maintaining product quality and
providing a safe working environment for the paint booth operator.
Because there are many dry filter system manufacturers and distributors, the availability
of the filter types discussed in this User's Guide is very high. The number of participants in this
market is on the increase, thus installation and operating costs may decrease and availability
increase in the future.
The maintainability of dry filter systems in general cannot be assessed; rather it is more
productive to evaluate each system individually in terms of the booth operating conditions. This
issue is addressed insofar as possible by providing filter replacement labor cost estimates ($/ft2)
for each type of filter. In addition, filter depletion rates (ft2/day) can be estimated from
Tables 5 through 8 by dividing the filter replacement cost ($/day) by the base filter cost (S/ft2).
These two quantities (filter depletion rates and filter replacement labor costs) must be combined
to determine the annual labor costs associated with the dry filter replacement.
53 ECONOMIC EVALUATION EXAMPLES: THE APPLICABILITY OF THE
CONVERSION OPTION FOR THREE DIFFERENT PAINT SPRAY BOOTHS
In this section, three examples are presented in which step-by-step instructions for
performing an economic evaluation are provided. The purpose of these examples is to illustrate
how the information presented in Section 5.2 may be used to determine the economic feasibility
of converting a water curtain paint spray booth to dry filter operation.
In each example, a description of the physical and operating characteristics of the booth
are provided. The characteristics were selected based on the results of the Navy paint booth
survey. The examples provided do not represent specific booths, rather each example represents
a general class of booths.
53.1 Conversion of a Small Crossdraft Paint Booth
The first example discusses the economic conversion of a small crossdraft paint spray
booth that has a light duty cycle.
56
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53.1.1 Paint Booth Characterization Before and After Conversion
The current physical and operating characteristics of the booth are:
• The booth is 9 ft wide, 9 ft high, and 10 ft long
• The booth is used less than one shift per day
• The average paint usage rate is 10 gal per week
• The average transfer efficiency is 30 percent
• Sump maintenance occurs once per month
• Wastewater from the sump is drained to an IWTP at negligible cost; sludge
collected at the bottom of the sump is drummed and disposed of as hazardous
waste
• Three drums of sludge are generated per year
• The air flowrate through the booth is approximately 10,500 cfm (125 linear fpm) x
(9 ft width) (9 ft height)
• The water curtain pressure drop is 0.8 inch w.c. due to the baffle system and spray
curtain
• The power ratings of both the exhaust fan and the water pump are 5 hp. The
Navy activity is considered an industrial user, therefore lower electricity rates
apply.
• There is no major sheetmetal rust or damage problem; however, 20 ft2 of minor
sheetmetal work is required
Because of the operating characteristics of the booth, the dry filter system selected for
installation is of the honeycombed paper variety. The decision was made not to remove the
water curtain baffles. The pressure drop from the PECS is therefore reduced from 0.8 inch w.c.
to 0.5 inch w.c. (it is assumed that the baffles contribute 0.4 inch w.c., and the filter system
contributes 0.1 inch w.c.). It is calculated that the fan motor may be downsized to 3 hp, and
replacement of the fan or motor is not necessary.
The required air flowrate through the booth will remain the same (10,500 cfm), and the
clean face velocity of the dry filter system is assumed to be 200 linear fpm. The minimum
required surface area is therefore approximately 55 ft2. The filters are available in widths of
45 inches (or 3.75 ft), thus the filter surface area must be at least 7.5 ft wide and 7.3 ft high. For
simplicity, it is assumed that the filter surface area is 7.5 by 7.5, or 56 ft2.
5.3.1.2 Identification and Estimation of Costs
The above system evaluation results, combined with the information provided in
Tables 4 through 12, is used to estimate PECS conversion costs and operating costs for both
the current and proposed systems. The cost estimations are obtained as follows:
57
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PECS Conversion Cost
The cost per square foot to install a honeycombed paper filter system is provided in
Table 4. If 56 ft2 of filter area is required, the cost to install the system is $530
(56 ft2 x $9.47/ft2). In addition, approximately 20 ft2 of minor sheetmetal work is required. This
work will cost approximately $176 ($8.8/ft2 x 20 ft2). The total cost to install the paper filter
system is approximately $706 ($530 + $176).
Utility Costs
The utility costs before and after conversion must be considered separately using
Table 10. Before conversion, two 5-hp motors are required to operate the paint booth. An
industrial user operating a 10-hp unit such as this for one shift per day requires $2.70 worth of
electricity per day, or $702 per year in constant dollars ($2.70 per day in 1989 x 260 days per
year). The NPV of the electrical operating cost for the current system over the economic life
of the booth is $5,007 ($19.26 per day x 260 days per year).
After conversion, the electricity required is for the operation of one 3-hp motor. An
industrial user operating a 3 hp unit one shift per day requires $0.81 worth of electricity per day,
or $211 per year in constant dollars ($0.81 per day in 1989 x 260 days per year). The NPV of
the electrical operating cost for the converted system over the economic life of the booth is
S 1,502 ($5.78 per day x 260 days per year).
Waste Treatment Costs
The only waste treatment cost of concern in this example is that associated with disposal
of the sludge collected at the bottom of the sump, after the supernatant liquid is drained. The
sludge disposal cost may be calculated from information presented in Table 9, under the column
entitled "Sludge only." The water curtain system in this example generates 3 drums of sludge
per year; this results in an annual waste treatment cost in constant dollars of $900 ($300 per
drum in 1989 x 3 drums per year). The NPV of the waste treatment cost over the economic life
of the booth is $6,597 ($2,199 per drum x 3 drums per year).
Equipment Costs
As discussed in Section 5.2, the only equipment cost considered is for the replacement
of spent filter media. Replacement costs for the filter type selected (honeycombed paper) may
be calculated from information presented in Table 5. For a paint usage rate of 10 gal per week,
S6.50 worth of filter media is depleted per week. This results in an annual filter cost in constant
dollars of $338 ($6.50 per week in 1989 x 52 weeks per year). The NPV of the filter replacement
cost over the economic life of the booth is $2,413 ($46.42 per week x 52 weeks per year).
Labor Costs
As with the utility cost calculations, the labor utility costs before and after conversion
must be considered separately using Tables 11 and 12.
Before conversion, the labor cost incurred is for draining and cleaning the water curtain
sump. Table 12 presents labor costs per drum generated; in this example, three drums of sludge
waste are generated per year. This results in an annual labor cost in constant dollars of $102
($34 per drum in 1989 x 3 drums per year). The NPV of the labor cost for the current system
over the economic life of the booth is $729 ($243 per drum x 3 drums per year).
58
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After conversion, the labor cost incurred is for spent filter media replacement. Table 11
presents labor costs per square foot of filter replaced. A parameter that must be calculated is
the filter depletion rate (or number of square feet of filter surface area depleted per week)
which is obtained from Table 5 by dividing the filter replacement cost in dollars per week by the
base cost per square foot. In this example, the depletion rate is 25 ft2 per week ($6.50 per
week/SO.26 per ft"). This depletion rate results in an annual labor cost in constant dollars of
$70 (SO.054 per ft2 in 1989 x 25 ft2 per week x 52 weeks per year). The NPV of the labor cost
for the dry filter system over the economic life of the booth is $505 ($0,389 per ft2 x 25 ft2 per
week x 52 weeks per year).
A summary of the one-time and recurring costs calculated in this section is presented
in Table 13.
5-3.1.3 Development of Cash Flow Diagrams for the Current and
Proposed Systems
The one-time and recurring costs calculated in constant dollars in Section 5.3.1.2 are
used to generate cash flow diagrams for the current and proposed systems. The recurring costs
must be summed separately for each system to determine annual recurring costs in constant
dollars.
TABLE 13. SUMMARY OF ONE-TIME AND RECURRING COST ESTIMATES FOR A
SMALL CROSSDRAFT BOOTH BEFORE AND AFTER CONVERSION
RECURRING COSTS
Water Curtain System Dry Filter System
I tem
Annual Constant
Dollar Cost ($)
NPV of 10 Year Life
Cycle Cost ($)
Annual Constant
Dollar Cost ($)
NPV of 10 Year
Cycle Cost
Ut iIi ties
$702
$5,007
$211
$1,502
Waste Treatment
$900
$6,597
$0
$0
Labor
$102
$729
$70
$505
Materials
$0
$0
$338
$2,413
Total
$1,704
$12,333
$619
$4,420
ONE-TIME COSTS
Item Cost ($)
Equipment & Installation $530
Sheetmetal Work $176
Total $706
59
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The cash flow diagram for maintaining the status quo with the water curtain system is
presented in Figure 18. Note that no one-time cost is included in this diagram. The recurring
cost ($1,704) in constant dollars is obtained by summing the recurring utility, waste treatment
and labor costs ($702, $900, and $102, respectively) in constant dollars calculated in
Section 5.3.1.2.
The cash flow diagram for the conversion option is presented in Figure 19. The one-
time cost included in the diagram is from the purchase and installation of the dry filter PECS.
The recurring cost ($619), in constant dollars, associated with the dry filter system is obtained
by summing the recurring utility, filter media and labor costs ($211, $338, and $70, respectively)
in constant dollars calculated in Section 5.3.1.2.
53.1.4 Calculation of the Savings to Investment Ratio
The SIR is calculated by taking the difference between the NPV of the recurring costs
of the present and proposed systems, and dividing the resultant by the total investment cost.
The NPV of the recurring costs of the current water curtain system is $12,333. This value is
obtained by summing the NPV of the recurring utility, waste treatment, and labor costs
associated with the water curtain system ($5,007, $6,597, and $729, respectively) calculated in
Section 5.3.1.2.
The NPV of the recurring costs of the proposed dry filter system is $4,420. This value
is obtained by summing the NPV of the recurring utility, filter media, and labor costs associated
with the water curtain system ($1,502, $2,413, and $505, respectively) calculated in
Section 5.3.1.2.
The total investment cost for the dry filter system selected in this example is $706. The
SIR is therefore 11.2. Based on this result, installation of the proposed dry filter system is a very
economical alternative.
5.3.1.5 Determination of the Discounted Payback Period
The discounted payback period for this example is determined by referring to Table C
found on page C-4 of the NAVFAC P-442 document. This table is used because the savings
accrued each year is constant (except for the fact that waste disposal costs will remain stable
over the first four years; this however will serve only to shorten the payback period, and is
therefore not considered relevant), and there is no lead time between system installation and
usage. With an SIR of 11.1 and an economic life of 10 years, the payback period for the
proposed alternative is less than 1 year.
53.2 Conversion of a Large Crossdraft Paint Booth
The second example discusses the economic conversion of a large crossdraft paint spray
booth having a moderate duty cycle.
53.2.1 Paint Booth Characterization Before and After Conversion
The current physical and operating characteristics of the booth are:
• The booth is 15 ft wide, 10 ft high, and 20 ft long
• The booth is used one shift per day
60
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YEARS
10
500
1000
1500
2000
2500
3000
Figure 18. Cash flow diagram: current operation of a small crossdraft booth.
YEARS
A 5 6
10
Q
-------
• The average paint usage rate is 20 gal per week
• The average transfer efficiency is 30 percent
• Sump maintenance occurs once every 2 months
• Wastewater from the sump is drained to an IWTP at negligible cost; sludge
collected at the bottom of the sump is drummed and disposed of as hazardous
waste
• Six drums of sludge are generated per year
• The flowrate through the booth is 18,750 cfm (125 linear fpm) x (10 ft high) x
(15 ft wide)
• The pressure drop across the water curtain PECS is 1.3 inches w.c. due to the
baffles, water curtain, etc.
• The power ratings of the exhaust fan and water pumps are 10 and 7.5 hp,
respectively. The Navy activity considered an industrial user, therefore lower
electricity rates apply.
• 20 ft2 of major sheetmetal modification and repair work is needed to remove the
water curtain baffles, and prepare the site for installation of the dry filter system
Because of the operating characteristics of the booth, a cloth filter replacement system
is selected. The high pressure drop (1.25 inches w.c.) associated with the cloth filter requires
removal of the water curtain baffles from the booth exhaust duct. After the baffle system is
removed, the pressure drop across the proposed cloth filter system is the same as that for the
water curtain system. Thus, no alteration of the exhaust fan system is required.
After conversion, the volume flowrate through the booth must remain at 18,750 cfm.
Assuming a cloth filter clean face velocity of 200 linear fpm, the minimum required filter surface
area is 94 ft". Cloth filters are available in widths of 3 ft, thus the resulting dry filter surface
area should have dimensions of 8 ft by 12 ft. The actual surface area is therefore 96 ft".
5322 Identification and Estimation of Costs
The one-time and recurring costs for the current and proposed systems in this example
are estimated in a manner similar to that presented in Section 5.3.1.2. The calculation results
for this example are summarized in Table 14.
5323 Development of Cash Flow Diagrams for the Current and Proposed Systems
The one-time and recurring costs calculated in constant dollars in Section 5.3.2.2 are
used to generate cash flow diagrams for the current and proposed systems. The recurring costs
must be summed separately for each system to determine annual recurring costs in constant
dollars.
The cash flow diagram for maintaining the status quo with the water curtain system is
presented in Figure 20. Note that no one-time cost is included in this diagram. The recurring
cost ($3,232) in constant dollars is obtained by summing the recurring utility, waste treatment
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TABLE 14. SUMMARY OF ONE-TIME AND RECURRING COST ESTIMATES FOR A
LARGE CROSSDRAFT BOOTH BEFORE AND AFTER CONVERSION
RECURRING COSTS
Uater Curtain System Dry Filter System
J tern
Annual Constant
Dollar Cost ($)
NPV of 10 Year Life
Cycle Cost ($)
Annual Constant
Dollar Cost ($)
NPV of 10 Year Life
Cycle Cost ($)
UtiIi ties
$1,228
$8,766
$702
$5,007
Waste Treatment
$1,800
$13,194
$0
$0
Labor
$204
$1,458
$135
$958
Materials
$0
$0
$582
$4,159
Total
$3,232
$23,418
$1,419
$10,124
ONE-TIME COSTS
I tem
Cost
($)
Equipment & Installation $996
Sheetmetal Work $314
Total $1,310
and labor costs ($1,228, $1,800, and $204, respectively) in constant dollars calculated in
Section 5.3.2.2.
The cash flow diagram for the conversion option is presented in Figure 21. The one-
time cost included in the diagram is from the purchase and installation of the dry filter PECS.
The recurring cost ($1,419) in constant dollars associated with the dry filter system is obtained
by summing the recurring utility, filter media and labor costs ($702, $582, and $135, respectively)
in constant dollars calculated in Section 5.3.2.2.
53.2.4 Calculation of the Savings to Investment Ratio
The SIR is calculated by taking the difference between the NPV of the recurring costs
of the present and proposed systems, and dividing the resultant by the total investment cost.
The NPV of the recurring costs of the current water curtain system is $23,418. This value is
obtained by summing the NPV of the recurring utility, waste treatment, and labor costs
associated with the water curtain system ($8,766, $13,194, and $1,458, respectively) calculated
in Section 5.3.2.2.
The NPV of the recurring costs of the proposed dry filter system is $10,124. This value
is obtained by summing the NPV of the recurring utility, filter media, and labor costs associated
with the water curtain system ($5,007, $4,159, and $958, respectively) calculated in
Section 5.3.2.2.
The total investment cost for the dry filter system selected in this example is $1,310.
The SIR is therefore 10.1. Based on this result, installation of the proposed dry filter system
is a very economical alternative.
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YEARS
5
10
SCO
o
CO
UJ
10C0
cr>
c
<
1500
2000
2500
3000
Figure 20. Cash flow diagram: current operation of a large crossdraft booth.
YEARS
5
5 •»»
c
250C
3C0C L-
Figure 21. Cash flow diagram: proposed operation of a large crossdraft booth.
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532.5 Determination of the Discounted Payback Period
The discounted payback period for this example is determined by referring to Table C
found on page C-4 of the NAVFAC P-442 document. With an SIR of 10.1 and an economic life
of 10 years, the payback period for the proposed alternative is less than 1 year.
533 Conversion of a Large Downdraft Paint Booth
The third example discusses the economic conversion of a large downdraft paint spray
booth having a fairly heavy duty cycle.
533.1 Paint Booth Characterization Before and After Conversion
The current physical and operating characteristics of the booth are:
• The booth is 20 ft wide', 25 ft high, and 40 ft long
• The booth floor consists of a large grate covering the water curtain sump
• There are four exhaust ducts, each drawing overspray from a 20 ft by 10 ft area
(approximately)
• The flowrate through each exhaust duct is 25,000 cfm (125 linear fpm) x
(10 ft width) (20 ft length), and each exhaust fan is rated at 20 hp
• There are four water pumps, each rated at 7.5 hp, that circulate water from the
sump
• The Navy activity is considered an industrial user, therefore lower electrical rates
apply
• The pressure drop across the water curtain PECS is 2.0 inches w.c. due to
presence of baffles, underground ducting, etc.
• The booth is used one and one-half shifts per day
• The average paint usage rate is 70 gal per week
• The average transfer efficiency is 30 percent
• Sump maintenance occurs three times per year
• Wastewater from the sump is drained to an IWTP at negligible cost; sludge
collected at the bottom of the sump is drummed and disposed of as hazardous
waste
• The grates are cleaned once per year
• Twenty-five drums of sludge are generated per year
• 120 ft2 of major sheetmetal modification and repair work is needed to remove the
water curtain baffles, and prepare the site for installation of the dry filter system
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Because of the operating characteristics of the booth, a cloth filter replacement system
is selected. The pressure drop associated with the cloth filter (1.25 inches w.c.) is considerably
less than that associated with the water curtain PECS (because the baffles will be removed), thus
the exhaust fans can be downgraded to 15 hp each. This requires the replacement of the fan
motors, because downsizing in this case is not possible.
After conversion, the volume flowrate through each exhaust duct must remain at
25,000 cfm. Assuming a cloth filter clean face velocity of 210 linear fpm, the minimum required
filter surface area associated with each exhaust fan is 119 ft2. Cloth filters are available in widths
of 3 ft, thus the resulting dry filter surface area associated with each fan should have dimensions
of 20 ft by 6 ft.
533.2 Identification and Estimation of Costs
The one-time and recurring costs for the current and proposed systems in this example
are estimated in a manner similar to that presented in Section 5.3.1.2. The results are
summarized in Table 15.
5333 Development of Cash Flow Diagrams for the Current and Proposed Systems
The one-time and recurring costs calculated in constant dollars in Section 5.3.3.2 are
used to generate cash flow diagrams for the current and proposed systems. The recurring costs
must be summed separately for each system to determine annual recurring costs in constant
dollars.
The cash flow diagram for maintaining the status quo with the water curtain system is
presented in Figure 22. Note that no one-time cost is included in this diagram. The recurring
constant dollar cost ($21,026) is obtained by summing the recurring utility, waste treatment and
labor constant dollar costs ($11,571, $7,500, and $1,955, respectively).
The cash flow diagram for the conversion option is presented in Figure 23. The one-
time cost included in the diagram ($27,044) is from the purchase and installation of the dry filter
PECS ($4,980), replacement of the exhaust fan motors ($2,320), major sheetmetal repair work
($1,888) and installation of the floor grate covering ($17,856). The recurring constant dollar cost
(S8,825) associated with the dry filter system is obtained by summing the recurring utility, filter
media and labor constant dollar costs ($6,314, $2,038, and $473, respectively).
533.4 Calculation of the Savings to Investment Ratio
The NPV of the recurring costs of the current water curtain system is $151,576. This
value is obtained by summing the NPV of the recurring utility, waste treatment, and labor costs
associated with the water curtain system ($82,645, $54,975, and $13,956, respectively) calculated
in Section 5.3.3.2.
The NPV of the recurring costs of the proposed dry filter system is $63,003. This value
is obtained by summing the NPV of the recurring utility, filter media, and labor costs associated
with the water curtain system ($45,088, $14,559, and $3,356, respectively) calculated in
Section 5.3.3.2.
As discussed in Section 5.3.3.3, the total investment cost for the dry filter system selected
in this example is $27,044. The SIR is therefore 3.6. Based on this result, installation of the
proposed dry filter system is a very economical alternative.
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TABLE IS. SUMMARY OF ONE-TIME AND RECURRING COST ESTIMATES FOR A
LARGE DOWNDRAFT BOOTH BEFORE AND AFTER CONVERSION
RECURRING COSTS
Water Curtain System Dry Filter System
Annual Constant NPV of 10 Year Life Annual Constant NPV of 10 Year Life
Item Dollar Cost (S) Cycle Cost ($) Dollar Cost ($) Cycle Cost (S)
Fan Motor Replacement $2,320
Equipment & Installation $4,980
Major Sheetmetal Work $1,888
Floor Grate Covering $17,856
Total $27,044
Utilities $11,571 $82,645 $6,314 $45,088
Waste Treatment $7,500 $54,975 $0 $0
Labor $1,955 $13,956 $473 $3,356
Materials $0 $0 $2,038 $14,559
Total $21,026 $151,576 $8,825 $63,003
ONE-TIME COSTS
Item Cost ($)
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0 1 2 3
5 OOC
10 000
C
<
i 15 000
20,000
25,000
3C.000
YEARS
4 5 6
9 10
Figure 22. Cash flow diagram: current operation of a large downdraft booth.
0 12 3 4
10.0CC
<
2C.000
25.000
30,000
YEARS -
5 6
8 9
o
in
Figure 23. Cash flow diagram: proposed operation of a large downdraft booth.
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532.5 Determination of the Discounted Payback Period
The discounted payback period for this example is determined by referring to Table C
found on page C-4 of the NAVFAC P-442 document. With an SIR of 3.6 and an economic life
of 10 years, the payback period for the proposed alternative is slightly less than 2 years.
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APPENDIX A
DRY FILTER SYSTEM CHARACTERISTICS
General and specific characteristics of most dry filter systems currently available on the
market are presented in this Appendix.
A-l GENERAL DRY FILTER CHARACTERISTICS
All dry filter systems operate on the same principle: particulate laden air drawn into
the filter is forced to rapidly change directions as it flows around the filter media. The
particulate, having more inertia than the surrounding air, impacts on the filter media and is
removed from the air flow. Dry filter systems operate in much the same way as mist eliminators.
The characteristics of all dry filter systems that affect performance are particulate
capacity, resistance to airflow, and particulate removal efficiency.
Particulate Capacity
Particulate capacity of the filter is the quantity of overspray particulate that the filter
is able to retain before replacement is required. The filter reaches maximum particulate capacity
when the pressure drop across it exceeds the design value specified by the manufacturer.
Resistance to Airflow
Minimizing the resistance to airflow through the filter is necessary to maintain the
required volume flowrate through the booth. Ideally, dry filters operate with Little flow resistance
until the particulate capacity is reached. This is generally not the case however, because airflow
resistance increases as the quantity of particulate captured by the filter increases.
Particulate Removal Efficiency
Particulate removal efficiency is a measure of how effectively the filter removes paint
particulate from spray booth exhaust. It is generally expressed as the percent of overspray
removed from the airflow. The removal efficiency is primarily dependent on the particulate size,
the spacing between obstructions presented by the filter media, and the velocity of air that passes
through the filter.
Small particles remain entrained longer than large particles because they are better able
to follow the flow of air around obstructions presented by the filter media. By tightly packing
the filter media, small particles are removed more efficiently; however the filter may quickly
become clogged. The air velocity also affects particulate removal efficiency; the higher the
flowrate, the higher the particulate inertia, and, correspondingly, the more Likely the particulate
is to impact the filter media.
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A-2 DRY FILTER TYPES
There are four principal filter types: fiberglass cartridge, multilayered honeycombed
paper, accordion-pleated paper, and cloth filters. Although each type is presented separately,
there are dry filter systems available in which one or more types of filters are combined. For
example, one filter manufacturer markets a system in which a honeycombed paper filter and a
cloth filter are combined for higher removal efficiency and particulate capacity.
Fiberglass Cartridge Filters
This type of filter finds widespread use due to low capital equipment and installation
costs, reasonable particulate capacities, and high particulate removal efficiencies. However,
filter replacement costs are relatively high. The filter media is composed of thin, closely packed
fiberglass filaments, and is generally encased in a cardboard frame held in place by an easily
assembled metal support structure. Cartridge sizes are approximately 20 inches long, 20 inches
high and 1 inch deep. The primary advantage to this type of filter is the associated low
installation cost.
There are several disadvantages to this type of filter. When filter changeout is required,
each cartridge must be individually replaced. This can result in considerable downtime if the
booth is heavily used, because of the high filter replacement rate. The support structure is
generally not built so that the filters fit tightly in the frame. Thus, as the filters become clogged
and airflow resistance through them increases, significant leakage of contaminated exhaust air
around the cartridges occurs.
Fiberglass cartridge filters are best deployed in booths that have light duty cycles (less
than one shift per day).
Multilayered Honeycombed Paper Roll or Pad Filters
Moderate capital equipment and installation costs and low filter replacement costs, fairly
high particulate capacities, and reasonably high particulate removal efficiencies characterize the
multilayered honeycombed paper filter systems. The filter media is composed of thin, loosely
connected paper strips that are combined to form a multilayered honeycomb pattern. The paint
booth exhaust flows through the strips, which become covered with paint overspray.
Honeycombed paper filters are available in pads or rolls; however the rolls require
significantly less time to replace. This is because the pads must be installed individually, and are
normally placed in two layers to increase particulate emission control. In addition, the price per
square foot is higher for pads than rolls.
Accordion Pleated Paper Sheet Filters
Low to moderate installation and operating costs, moderate capacities, and moderately
low particulate removal efficiencies are associated with accordion-pleated paper sheet filters.
The media is composed of layers of pleated paper attached at the folds. The paint booth
exhaust air flows through staggered rows of perforations which honeycomb the layers of paper.
A schematic diagram illustrating how these filters operate is given in Figure A-l. (Reference 2).
The advantage of pleated paper filters is that they are quickly and easily replaced. The
downtime associated with pleated paper filters replacement is somewhat less than with cloth or
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Figure A-l. Schematic Diagram Illustrating the Pleated Paper
Filtration Process
72
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multilayered honeycombed paper rolls, and significantly less than with pad or cartridge type
filters.
The primary disadvantage of the pleated paper filter is that the particulate removal
efficiency is low compared to the other filter types. However, the control capabilities of this type
of filter should be sufficiently high to maintain most, it not all, Navy paint booths in compliance
with applicable regulations. In addition, difficulties may arise if they are used in areas of
constant, high humidity, or if significant quantities of water based paints are used. The presence
of excess moisture can cause the filter media to sag and allow unfiltered air to be emitted.
Cloth Filters
A variety of cloth filters are available on the market. The operating costs associated
with these filters are low; however installation costs may be slightly higher than for other filter
types. Cloth filter removal efficiencies and capacities are both high. Filter media is composed
of specially designed woven or nonwoven cloth. It is available in thicknesses ranging from 0.25
to 1 inch, and in pads or rolls up to 400 ft in length.
Cloth roll filters have several distinct advantages over other types of filters. They are
generally less expensive per square foot than other filters. One manufacturer claims that the
capacity of their cloth roll filter is four times higher than that of pleated paper filters, and
replacement filters cost one half as much. The cloth filter may therefore require much less
frequent replacement. In addition, particulate removal efficiencies are high. The downtime
associated with cloth roll filter replacement is significantly less per square foot than that required
to replace cartridge and pad filters.
Another advantage of cloth roll filters is that they may be automatically deployed. In
an automatic deployment system, the pressure differential across the filter is continuously
monitored. When it reaches the limit specified by the manufacturer, clean filter media is
unrolled from the top to replace used filter media, which is collected on a roll at the bottom.
The advantage of automatic versus manual deployment is that the filter is changed only when
necessary, not when the filter appears dirty. This reduces operating and filter disposal costs,
and eliminates most of the downtime associated with filter replacement. It should be noted,
however, that there have been reports that the automatic deployment system does not operate
satisfactorily.
The primary disadvantage of cloth roll filter systems is that installation costs may be
higher than for other systems, especially if an automatic deployment system is installed. The
pressure differential associated with this type of filter is often higher than for the other type of
filters, and may require upgrading or replacement of the fan motor.
These higher installation costs are often mitigated by the lower replacement filter costs
and a significant reduction in downtime required for filter replacement. Automatically deployed
filters are most suitable to high production booths (two or more shifts per day), while manually
deployed systems are suitable for all booths, regardless of booth duty cycles.
A3 Determination of Minimum Required Particulate Removal Efficiency
A3.1 Compliance With Emissions Regulations
To determine whether or not the selected filter is capable of complying with local air
pollution control regulations, the following analysis should be done:
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• Step 1: Multiply the density of the paint (in lbs per gallon) by the percent solids
content (approximately 50 percent for military paints), one minus the transfer
efficiency (approximately 70 percent), the paint usage rate (in gallons per paint
cycle); and divide this quantity by the air flowrate through the booth. Convert the
results to the metric system (mg per cubic meter). This yields the particulate
concentration of particulate emitted.
• Step 2: Determine the allowable particulate emission concentration, which is
generally reported in mg per cubic meter. This is accomplished by contacting the
appropriate air pollution control agency listed in Section 4.
• Step 3: Divide the allowed emission rate by the calculated actual emission rate,
subtract this quantity from one, and multiply by 100. The result is the minimum
required removal efficiency for the filter system selected to maintain the facility
in compliance.
A sample calculation is provided below. The values used for paint density, transfer
efficiency, and solids content are fairly representative of military coating operations. The duty
cycle (50 gallons per day) was selected to illustrate what may be considered a "worst case
scenario," in which high particulate concentrations are encountered. The flowrate is fairly low
for a booth with such a high production rate; however it was selected also for the purpose of
illustrating a worst case situation.
Step 1:
[9 lb] [50 gal] [0.5 lbs solids] 1 hr 0.000016 lb
x x x 0.70 x =
gal 8 hr [1 lb paint] [1,200,000 ft3] [ft3]
(convert to metric units)
[0.000016 lb] ft3 1 kg [106 mg] [266 mg]
X X X =
ft3 0.028 m3 [2.2 lb] kg [m3]
Step 2: For the Los Angeles area, the particulate concentration limit is 123 mg/m3, which is
probably one of the lowest emission limits in the country. For a reasonable safety margin
assume the limit is 100 mg/m3.
Step 3:
100 mg
1 - ——— = 0.62 x 100 = 62% removal efficiency is required.
266 mg
The removal efficiency of the pleated paper filter should be high enough to meet this
requirement.
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A32 Other Removal Efficiency Requirements
If the paint spray booth to be converted is also a target for future VOC emission control
requirements, the particulate removal efficiency of the proposed dry filter system (as well as
the current water curtain system) may be critical. This is because some VOC emission control
systems (i.e., carbon adsorption and catalytic incineration) cannot tolerate any appreciable
amount of particulate present in the process flow. For this and other reasons, these systems are
often not recommended for use in controlling VOC emissions from military painting operations.
However, if a VOC emission control device is to be installed on the booth, the minimum
required particulate removal efficiency issue should be carefully considered.
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