E PA-600/R-97-039
April 1997
Final Report
Options for Reducing
Refrigerant Emissions
from Supermarket Systems
By
Eugene F. Troy
ICF Incorporated
1850 K Street, NW, Suite 1000
Washington, DC 20006
EPA Contract 68-D3-0021, WA 3-19
Project Officer: Cynthia L. Gage
Air Pollution Prevention and Control Division
National Risk Management Research Laboratory
Research Triangle Park, NC 27711
U.S. Environmental Protection Agency
Office of Research and Development
Washington, DC 20460
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FOREWORD
The U. S. Environmental Protection Agency is charged by Congress with pro-
tecting the Nation's land, air, and water resources. Under a mandate of national
environmental laws, the Agency strives to formulate and implement actions lead-
ing to a compatible balance between human activities and the ability of natural
systems to support and nurture life. To meet this mandate, EPA's research
program is providing data and technical support for solving environmental pro-
blems today and building a science knowledge base necessary to manage our eco-
logical resources wisely, understand how pollutants affect our health, and pre-
vent or reduce environmental risks in the future.
The National Risk Management Research Laboratory is the Agency's center for
investigation of technological and management approaches for reducing risks
from threats to human health and the environment. The focus of the Laboratory's
research program is on methods for the prevention and control of pollution to air,
land, water, and subsurface resources; protection of water quality in public water
systems; remediation of contaminated sites and groundwater; and prevention and
control of indoor air pollution. The goal of this research effort is to catalyze
development and implementation of innovative, cost-effective environmental
technologies; develop scientific and engineering information needed by EPA to
support regulatory and policy decisions; and provide technical support and infor-
mation transfer to ensure effective implementation of environmental regulations
and strategies.
This publication has been produced as part of the Laboratory's strategic long-
term research plan. It is published and made available by EPA's Office of Re-
search and Development to assist the user community and to link researchers
with their clients.
E. Timothy Oppelt, Director
National Risk Management Research Laboratory
EPA REVIEW NOTICE
This report has been peer and administratively reviewed by the U.S. Environmental
Protection Agency, and approved for publication. Mention of trade names or
commercial products does not constitute endorsement or recommendation for use.
This document is available to the public through the National Technical Information
Service, Springfield, Virginia 22161.
PROTECTED UNDER INTERNATIONAL COPYRIGHT
ALL RIGHTS RESERVED.
NATIONAL TECHNICAL INFORMATION SERVICE
U.S. DEPARTMENT OF COMMERCE
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TECHNICAL REPORT DATA
(Please read Instructions on the reverse before corns
11 111! I 111 III
llllll II III
1. REPORT NO. 2.
EPA-600./R-97-039
I I 111! I llllll III
PB97-K
i
1 II 111 II III
57100
4, TITLE AND SUBTITLE
Options for Reducing Refrigerant Emissions from
Supermarket Systems
S, REPORT DATE
April 1997
6. PERFORMING ORGANIZATION CODE
7, AUTHOR(S)
Eugene F. Troy
8. PERFORMING ORGANIZATION REPORT NO.
9. PERFORMING ORGANIZATION NAME AND ADDRESS
ICF Incorporated
1850 K Street, NW, Suite 1000
Washington, DC 20006
10. PROGRAM ELEMENT NO.
11. CONTRACT/GRANT NO.
68-D3-0021, Task 3-19
12, SPONSORING AGENCY NAME AND ADDRESS
EPA, Office of Research and Development
Air Pollution Prevention and Control Division
Research Triangle Park, NC 27711
13. TYPE OF REPORT AND PERIOD COVERED
Final; 2-9/94
14. SPONSORING AGENCY CODE
EPA/600/13
is.supplementary notes _appcd project officer is Cynthia L. Gage, Mail Drop 62B, 919/
541-0580.
is, abstract rep0r|- was prepared to assist personnel responsible for the design,
construction, and maintenance of retail food refrigeration equipment in making know-
ledgeable decisions regarding the implementation of refrigerant-emissions-reducing"
practices and technologies. It characterizes the design of typical supermarket re-
frigeration systems and focuses on why these types of systems have high rates of re-
frigerant emissions. Three case studies are provided of companies that have succes-
sfully implemented emission-reducing practices and technologies. The report dis-
cusses a variety of technical and procedural options that can be applied to existing
systems and in new construction.
17. KEY WORDS AND DOCUMENT ANALYSIS
a. DESCRIPTORS
b.IDENTIFIERS/OPEN ENDED TERMS
c. COSATI Field/Group
Pollution Ozone
Refrigerants Stratosphere
Emission
Food
Commercial Buildings
Commissaries
Pollution Prevention
Stationary Sources
Supermarkets
Stratospheric Ozone
13B 07B
13A 04A
14G
06H
13 M
15E
13. DISTRIBUTION STATEMENT
Release to Public
19. SECURITY CLASS (ThisReport)
Unclassified
21. NO. OF PAGES
56
20. SECURITY CLASS (This page)
Unclassified
22. PRICE
EPA Form 2220-1 (9-73)
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SUMMARY
This report was prepared to assist personnel responsible for the design, construction and
maintenance of retail food refrigeration equipment in making knowledgeable decisions regarding the
implementation of refrigerant-emissions-reducing practices and technologies. The report first characterizes
the design of typical supermarket refrigeration systems and focuses on why these types of systems have high
rates of refrigerant emissions. Three case studies also are provided of companies that have successfully
implemented emission-reducing practices and technologies. The report concludes with a discussion of a
variety of technical and procedural options that can be applied to existing systems and in new construction.
ii
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TABLE OF CONTENTS
Summary ii
List of Tables v
Abbreviations and Acronyms ..
Chapter 1
1.1
1.2
1.3
1.2.1
1.2.1.1
1.2.1.2
1.2.1.3
1.2.1.4
1.2.2
1.2.3
1.3.1
1.3.1.1
1.3.1.2
1.3.2
1.3.3
1.3.4
1.3.5
Chapter 2
2.1
2.2
2.3
2.4
2.5
2.6
2.7
2.8
Chapter 3
3.1
3.2
3.3
3.4
3.5
3.6
3.7
3.8
Characterization of Supermarket Refrigerant Emissions
VI
1
Background 1
Sources of Refrigerant Emissions 3
Equipment Design and Construction 3
Piping 4
Piping Joints and Connections 6
Valves 6
Seals and Other Sources 6
Operations and Maintenance (O & M) Practices 6
Corporate Policies and Practices 7
Options for Preventing Refrigerant Emissions 8
Equipment Design and Construction 8
Design 8
Construction 9
Operations and Maintenance Practices 9
Non-CFC Refrigerants 10
Summary of Equipment-related Alternatives 12
Comprehensive Corporate Refrigerant Management 13
Chapter 1 References
Case History: Hannaford Brothers Company
16
17
Engineering the Emissions Out 17
Loop Piping Designs 18
No More Hot-Gas Defrost 18
Improved Construction Practices 19
Improved System Component Designs 19
Improved Maintenance Practices 19
Incentives for Contractors 20
Program Results 20
Case History; Shaw's Supermarkets
An Emissions Reduction Program
The Maintenance Manager
Underground Piping
Stationary Leak Detectors
Charge Reduction
Eliminating Capillary Tubes
Improving Maintenance
Results of the Program
21
21
22
22
23
23
24
24
25
ill
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Chapter 4 Case History: Jitney-Jungle Stores of America 26
4.1 Refrigerant Conservation Opportunities 26
4.2 Vertical Full-charge Surge Receivers 26
4.3 All-sweat Thermostatic Expansion Valves 27
4.4 Improved Mechanical Room Conditions 27
4.5 Improved Service and Maintenance Program 27
4.6 Installation of Isolation and Access Valves 28
4.7 Reducing Emissions during Conversions 28
4.8 Reducing Emissions through Equipment Replacements 29
Chapter 5 Emission-reducing Technologies and Practices 30
5.1 Introduction 30
5.2 Emission-reducing Technologies for New and Retrofit Construction 30
5.2.1 Technologies to Control Damage from Accidents,
Vibration and Pulsation 31
5.2.2 Technologies to Replace or Substitute for High-emitting
Technologies 32
5.2.3 Technologies to Maintain System Cleanliness and Dryness 33
5.2.4 Technologies to Effectively Manage Refrigerant 33
5.2.5 Refrigerant Leakage Monitoring Technologies 35
5.2.6 Summary Tables 35
5.3 Emissions-reducing Operating Practices 36
5.3.1 Construction Practices 36
5.3.2 Repair Service and Preventive Maintenance 40
5.4 Analysis of Data on Refrigerant Emissions 42
5.4.1 Midwestern Chain Recharging Reports 43
5.4.2 South Coast Air Quality Management District Audit Reports 46
Chapter 5 References 49
iv
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TABLES
Number Page
1.1 PIPING AND CONNECTIONS REQUIRED IN A MID-SIZED SUPERMARKET 5
1.2 REFRIGERANT ALTERNATIVES FOR SUPERMARKETS 14
5.1 COSTS AND BENEFITS OF LEAK REDUCTION TECHNOLOGIES -
PARALLEL THREE-COMPRESSOR LOW-TEMPERATURE R-502 RACK 37
5.2 COSTS AND BENEFITS OF LEAK REDUCTION TECHNOLOGIES -
SINGLE-COMPRESSOR MEDIUM-TEMPERATURE R-12 RACK 38
5.3 COSTS AND BENEFITS OF OTHER LEAK REDUCING OPTIONS -
PARALLEL THREE-COMPRESSOR LOW-TEMPERATURE R-502 RACK 39
5.4 COSTS AND BENEFITS OF OTHER LEAK REDUCING OPTIONS -
SINGLE-COMPRESSOR MEDIUM-TEMPERATURE R-12 RACK 39
5.5 REFRIGERATION SUB-SYSTEM RELEASES AT A MIDWESTERN SUPERMARKET CHAIN 45
5.6 STATISTICAL ANALYSIS OF SCAQMD AUDIT REPORTS 48
V
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ABBREVIATIONS AND ACRONYMS
ANPRM
Advance Notice of Proposed Rule Making
ARI
Air-conditioning and Refrigeration Institute
ASHRAE
American Society of Heating, Refrigerating and Air-conditioning Engineers
CAAA
Clean Air Act Amendments
CFC
Chlorofluorocarbon
DX
Direct Expansion
EMS
Energy Management System
EPR
Evaporator Pressure Regulator
FM1
Food Marketing Institute
GWP
Global Warming Potential
HCFC
Hydrochlorofluorocarbon
HFC
Hydrofluorocarbon
NPV
Net Present Value
ODP
Ozone Depleting Potential
ODS
Ozone Depleting Substance
SCAQMD
South Coast Air Quality Management District
SNAP
Significant New Alternatives Program
UNEP
United Nations Environment Programme
vi
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CHAPTER 1
Characterization of Supermarket Refrigerant Emissions
The purpose of this chapter is to:
Review the legal requirements that pertain to refrigerant emissions and the impact
of those requirements on the supermarket industry;
* Identify the basic causes of refrigerant emissions in supermarket refrigeration
systems; and
• Discuss options that supermarket owners have to control refrigerant emissions and
their associated costs.
1.1 Background
The Montreal Protocol, an international treaty to reduce the use of ozone-depleting substances
(ODSs) was signed in 1987. The Protocol required all signatory parties to begin reducing their production of
ODSs on a national level. Later amendments to the Protocol further restricted ODSs, calling for a complete
phaseout of the production of CFCs and other ODSs. EPA has used its authority under Title VI of the Clean
Air Act Amendments (CAAA) of 1990 to develop regulations to phase out the production of CFCs and HCFCs,
including the refrigerants most favored for supermarket use, CFC-12, CFC-115 (a component in the blend
R-502), and HCFC-22. The CAAA also required EPA to develop regulations that require refrigerant recycling
and to approve new refrigerant substitutes.
The Phaseout of Production and Consumption of Class I Substances (CFCs), administered by
the EPA, includes a progressively declining cap on the total national production and importation of CFCs. The
cap on CFC production will continue to decrease annually until December 31, 1995. After 1995, other than
in very limited circumstances, production and importation of CFCs will be prohibited. (Reference. CAAA,
Section 604, 1990) The phaseout of HCFC-22 is scheduled to begin in the year 2004, with production
scheduled to cease in the year 2020. Congress has also instituted an escalating excise tax on virgin CFCs
and CFC-containing blends, which is administered by the IRS.
Prices of CFCs have risen since the beginning of the phaseout on production in large measure
because of the decreasing supply of CFC refrigerants and the increasing taxes. Taxes on virgin CFCs are
scheduled to continue to increase until production ceases at the end of 1995. After this date, prices of CFCs
are likely to escalate more rapidly because of the expected decrease in availability of replacement CFC
refrigerants. Availability of CFCs after the phaseout date is largely dependent on the rate of refrigerant
recycling and the demands of other sectors, in particular mobile air-conditioners.
In 1993, EPA issued regulations mandating the recycling of ODSs entitled The National Recycling
and Emission Reduction Program (also known as the Recycling Rule). (Reference: CAAA, Section 608,
1990; and Federal Register, May 1993) These regulations became effective June 14, 1993 and require
persons working on refrigeration and air-conditioning systems containing ODSs to maximize the recapturing
and recycling of ODSs during the maintenance, service, and disposal of these systems. Specifically, the
Program prohibits the intentional venting of these substances and requires the use of refrigerant recovery
devices prior to servicing or disposing of ODS-containing equipment. The regulations were designed to
maintain the availability of CFCs as long as possible without additional production through reuse and
containment of existing CFCs. The main provisions of the rule that most affected the supermarket industry
were:
mandatory recovery of refrigerant during equipment service;
required certification of technicians; and
1
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requirements for leak repair of systems with refrigerant charge sizes of 50 pounds
or more.
The first provision, recovery of refrigerants, affects ail departments of supermarket facilities
operations. Engineering personnel now have an additional reason to specify valves to isolate refrigerant in
the systems, valves to access the refrigerant, and components to allow refrigerant to be pumped into the
receiver during service. Maintenance personnel need to carefully schedule service to include the extra time
required to recover refrigerant. Operations personnel also have extra motivation to increase preventive
maintenance to avoid the longer downtimes should equipment require service. Furthermore, portable
refrigerant recovery devices must be supplied for all service trucks, with larger devices made available for
large recovery jobs.
As of November 14,1994, technicians are required to pass an EPA-approved certification test in order
to handle or purchase ODS refrigerants. For many companies the expense of certification is significant.
However, for technicians to pass the test they must be knowledgeable of the effects that refrigerant emissions
have on the atmosphere. Certified technicians that are conscientious are likely to take actions to prevent
refrigerant emissions, and thereby minimize the cost of recharging with increasingly expensive ODS
refrigerants. In this way some of the costs of certification can be recuperated.
The requirements for leak repair of systems with large charges will affect almost all companies, as
most supermarket systems piped out of a remote equipment room contain at least 50 pounds of refrigerant.
These requirements will be a challenge for some companies to meet. However, since the cap on leakage
rates was set at 35 percent of the total charge contained by each system, the imposition of additional
hardships beyond that already imposed by the economics of the refrigerant market will not likely be
substantial. If a store is actually leaking in excess of the amount allowed by law, simple and cost-effective
measures can usually be taken to reduce the leakage rate to compliance levels; moreover, savings from
reduced CFC usage will likely exceed compliance costs.
On February 15,1994 EPA announced its final Significant New Alternatives Policy (SNAP) Rule,
which establishes the structure by which the Agency evaluates substitute chemicals and processes for their
potential effects on human health and the environment. (Reference; CAAA, Section 612,1990; and Federal
Register, March 1994) This rule lists the substitutes that EPA has reviewed and found to be acceptable or
unacceptable in key industrial use sectors, including supermarket refrigeration and air-conditioning. At
present, the list of substances approved by EPA for commercial refrigeration use includes the refrigerants
HCFC-22, HFC-134a, HFC-227ea, ammonia, and the blends R-401A, R-401B, R402A, R-402B, R-404A, R-
406A, R-407A, R^07B, R^08A, R^09A, and R-507, (Reference: Federal Register, March 1994 and August
1994) EPA will update the list as new chemicals are submitted and evaluated.
Impact on the Supermarket Industry
In prior years when CFCs were thought to be environmentally harmless, the price of refrigerants was
such that it was uneconomical (from the company's perspective} to expend resources locating and repairing
less severe refrigerant leaks when working with supermarket refrigeration equipment. Choosing between
recharging a system and finding and repairing a leak was an economic decision. In many instances it was
less expensive to recharge. These practices resulted in the release of thousands of tons of ODS refrigerants
annually.
Design and construction of these systems reflected a similar economic philosophy. Prevention of
refrigerant emissions was only one of many design criteria evaluated in planning store layouts. Compromises
were constantly made between engineering design, economics, and store ambiance.
The prohibition on refrigerant venting has now added a legal aspect to the issue of refrigerant
emissions. Responding to the situation, many refrigeration engineers, construction mechanics, and
maintenance personnel have become more aware of the impact of their equipment specifications and
operating procedures on refrigerant emissions. Some company executives have educated themselves on
the issue, and have encouraged changes in operating procedures by their staff. More and more supermarkets
are now investing resources to control refrigerant leaks from their refrigeration systems.
2
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Emissions of CFCs are recognized as harmful because of the resulting ozone depletion. As a result,
many supermarkets adopted a double-pronged approach of reducing leakage from existing CFC systems in
conjunction with moving to alternative refrigerants. At the time of the issuance of the original ODS Phaseout
regulations in 1990, the only alternative available on the market was HCFC-22. Most supermarkets began
to move towards the use of HCFC-22 immediately, but only in medium-temperature (non-frozen) applications.
The use of HCFC-22 posed major problems in low-temperature applications; even though HCFC-22
had been used in prior years in these applications, low-temperature HCFC-22 equipment had not been
manufactured for a generation. As a result, new equipment had to be developed to handle the stresses
imposed by HCFC-22 in this application. At the same time, refrigerant manufacturers were aggressively
developing non-CFC refrigerant options such as HFCs to replace CFC-12 and R-502 in supermarket
applications.
Two kinds of refrigerant alternatives were eventually developed by the manufacturers: interim and
long-term. The interim refrigerants were designed to be used as replacements to CFCs in existing equipment
and were composed of blends of HCFCs and other chemicals. The long-term options were designed to be
used in new equipment and had some potential as retrofit refrigerants; the long-term options were composed
of various HFCs.
Many of the HFC-based long-term options tend to have large Global Warming Potentials (GWPs).1
Consequently, supermarkets that are focused on environmental protection are now exercising considerable
care in their choices of refrigerants and equipment designs. Moreover, instituting practices to reduce ODS
emissions now will have an added environmental benefit of reducing emissions of HFC-based refrigerants
as they are applied in supermarket systems.
1.2 Sources of Refrigerant Emissions
Refrigerant emissions from supermarket refrigeration systems are affected by (1) original equipment
design and construction, (2) maintenance and repair practices, and (3) corporate policy. This section
qualitatively describes:
how the design and construction of equipment can influence refrigerant emission
levels during normal operation;
how maintenance and repair personnel can impact whether the systems they care
for are leaky or leak-tight; and
how a company's policies have a indirect influence on emission levels.
A quantitative evaluation of these items is provided in Chapter 5.
1.2.1 Equipment Design and Construction
Supermarket refrigeration systems operate on the commonly-used vapor-compression
thermodynamic cycle. This cycle produces cooling by circulating a refrigerant through various components
in which the refrigerant alternately absorbs heat from a refrigerated space and then rejects the heat to a
warmer space. The cycle requires four basic components:
1 The GWP of a chemical is an indicator of its estimated contribution to the environmental problem of
global warming. Chemicals that have a greater ability to absorb and emit infrared radiation are likely to
have greater GWPs than those which do not. Furthermore, chemicals that have long atmospheric
lifetimes, such as HFCs, are also likely to have greater GWPs than those which do not
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~ the evaporator coil (located in the walk-in box or display case), in which the liquid
refrigerant boils off at a low temperature under low pressure as it absorbs heat from
the refrigerated space;
the compressor (located on the compressor rack or condensing unit), which
increases the pressure and temperature of the refrigerant gas, enabling it to liquify
at a high temperature;
the condenser coll, which liquifies the refrigerant by rejecting heat from the hot, high-
pressure refrigerant gas to a cooling medium that can be either air, in the case of an
air-cooled condenser (typically located outside the store) or water, in the case of a
shell-and-tube condenser (typically located inside the store); and
* the expansion valve (located immediately before the evaporator coil), which reduces
the pressure of the liquid refrigerant, enabling it to boil at the tow temperatures
required in the refrigerated space.
In addition to the four basic components, other components are also required to make the system
operate smoothly. These components include:
• piping, to connect all of the components together;
a receiver, to allow refrigerant from the system to be stored when not required;
suction liquid accumulators, to prevent liquid refrigerant that fails to boil off in the
evaporator or suction line from entering the compressor;
control and shut-off valves, to divert refrigerant to where it is needed and stop or
throttle refrigerant flow as required;
refrigerant filters and driers, to protect system components from damage from
moisture and other impurities that have remained in the system after construction or
that have developed in the system over time;
an oil management system, which returns oil driven out of the compressor back to
the crankcase of the compressor; and
electronic and mechanical controls to provide safe, efficient, and effective operation
of the entire system.
Heat reclamation coils may also be included in the system to preheat air in the air handling unit or
water for the domestic hot water. These coils remove useful heat from the hot refrigerant gas discharged from
the compressors, thereby increasing energy efficiency.
1.2.1.1 Piping
In theory, refrigeration and air-conditioning systems indefinitely recycle their refrigerant charge for
reuse and should not require additional refrigerant to operate properly for their entire useful lives. For
example, each year thousands of domestic refrigerators and window air-conditioners are retired to the landfill
with the original refrigerant charge intact. It should be stressed, however, that these self-contained appliances
contain refrigerant tubing lengths of 50 feet or less and therefore are appreciably less prone to the refrigerant
emissions associated with the long piping lengths of the large commercial equipment found in supermarkets.
It is because of the long piping lengths and their associated large numbers of joints and connections
that refrigerant emissions in commercial refrigeration systems are so difficult to control. With many
connections and miles of piping to design, build and maintain, supermarket facilities personnel face a big
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challenge in controlling refrigerant emissions. Furthermore, the heat, vibration, and high pressures developed
during the refrigeration cycle only exacerbate any existing leakage situation. The estimates in Table 1.1 below
represent the quantity of refrigeration equipment required to operate a mid-sized full-service supermarket.
(Reference: Bittner, 1992)
The type of refrigerant piping used in supermarkets is designed to be much stronger than required
to counteract the internal pressures to which it is typically subjected. As a result, refrigerant leaking directly
from undamaged piping is uncommon. However, emissions of refrigerant from piping can result from the
following scenarios:
by locating piping in unprotected high-traffic areas, on top of cooler boxes or display
cases, resulting in possible crushing;
by using hot refrigerant gas to defrost evaporator coils, causing piping to rapidly
expand and contract approximately 1,000 times annually for the life of the
equipment, resulting in metal fatigue of the pipe;
by improperly securing field piping, compressor rack piping, or capillary tubes on
pneumatic pressure controls, resulting in abrasion from vibrations or thermal
expansion and contraction; and
by improperly mounting or securing condenser or heat reclaim piping, resulting in
abrasion from vibrations or thermal effects and exacerbating galvanic corrosion.
Any failures occurring in refrigerant piping can result in catastrophic loss of the entire refrigerant
charge. In general, piping located on the compressor rack or condensing unit is very vulnerable to
catastrophic failure because of the high levels of vibration transmitted from the compressors. Furthermore,
piping located on the high-pressure side of the compressor is the most vulnerable to catastrophic failure
because it is subjected to the same high levels of vibration as well as high temperatures and gas pulsation.
TABLE 1.1
PIPING AND CONNECTIONS REQUIRED IN A MID-SIZED SUPERMARKET
Equipment
Piping Length (Miles)*
Number of Connections
Display Fixtures
6.8
6,400
Air-cooled Condensers
4.4
3,600
Heat Reclaim and
DX Air-conditioning Coils
1.4
1,200
Evaporator Coils
(Walk-in Coolers and Freezers)
1.2
2,100
Compressor Racks
0.1
1,200
Field Piping
4.0
1,700
TOTAL
17.9
16,200
a 1 mile = 1.609 km
5
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1.2.1.2
Piping Joints and Connections
As shown in Table 1.1, an average supermarket contains over 16,000 joints and connections.
Emissions from piping connections and component connections are much more common than from the actual
piping; moreover, emissions tend to occur continuously, as opposed to all at once. Connections come in three
types;
Brazed connections are typically found in long runs of field piping and on return
bends on heat exchangers such as evaporator and condenser coils. They are the
most leak-resistant of connections, but take longer to assemble and disassemble.
Flanged connections can typically be found on non-piping components, such as
replaceable-core filter-driers or the end bells of semi-hermetic compressors. These
type of connections lend themselves to easy disassembly, but are high-maintenance
and leaky due to the fact that gaskets or O-rings are required.
Screwed or flared connections are typically found on high-service items, such as
controls and expansion valves. These types of connections are the most leaky of
the three, and poor construction is the chief cause of the leakage.
1.2.1.3 Valves
Releases from valves can also be significant Not only do valves leak from flare or flange connections
used in their installation, but also from external ports on the valves. Schrader valves are among the greatest
offenders. These types of valves are used for attaching pressure gauges and for refrigerant transfer to/from
refrigeration systems. Valve caps are sometimes constructed of plastic instead of gasketed brass, and
consequently the valves leak even when capped. Common practice for some mechanics is to leave the caps
off altogether, increasing the leakage rate.
Another substantial source of refrigerant leakage is the expansion valve. Typically these valves come
with flared connections for ease of installation. When the valve is repeatedly subjected to freezing and
thawing many times, ice can form in the threads of the valve, causing the flare to unseat and resulting in a
steady-state leak.
Finally, relief valves on supermarket systems are nearly always found to be leaky, due to the their
mode of operation and type of construction. Receiver-mounted relief valves are constantly subjected to high
refrigerant pressures and are vulnerable to contamination and corrosion. In addition, these types of valves
frequently do not reseat completely following a pressure relief event.
1.2.1.4 Seals and Other Sources
After many years of use, the seats on open-drive-type compressors eventually become leaky due to
misalignment of the drive shaft entering the compressor. These seals can become a large source of steady-
state refrigerant emissions as they age and deteriorate.
Galvanic corrosion at the junction of dissimilar metals is also a frequent problem with certain
components made of metals other than copper, such as steel. This is usually the case for suction
accumulators and suction filters. Places where dissimilar metals come into contact need to be monitored
closely for leakage.
1.2.2 Operations and Maintenance (O & M) Practices
The historically low cost of replacement refrigerants has been the primary reason that the refrigeration
industry had favored low-first-cost designs over low-emission designs. As a result, many O & M personnel
6
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lacked training in low-emissions practices. However, more and more O & M personnel are becoming aware
of the impact their operating procedures have on refrigerant emissions through additional education and
training.
This transition away from old practices has been neither smooth nor easy for those in the trade who
do not believe that supermarket systems can be low-emitting. Skill levels in the refrigeration trade are now
becoming more critical to a company's "bottom line" and more companies are now investing in additional
educational and training opportunities for their O & M personnel. Additional education and training will have
the largest benefit in cases where mechanics can be sufficiently relieved from system repair duties so that
time is available to engage in thorough preventive maintenance. Finally, when maintenance personnel are
held personally accountable for refrigerant consumption, they often discover ways to reduce refrigerant
consumption while simultaneously managing their other responsibilities in an effective manner.
1.2.3 Corporate Policies and Practices
Corporate policies and practices to protect supermarkets' investment in refrigeration equipment and
to ensure cost-effective operations should be evaluated to ensure that they do not hinder the development
of a program to reduce refrigerant emissions. Since an emissions reduction program requires changes in
operating procedures by nearly all facilities departments, persons attempting to implement such a program
may encounter resistance from individuals who do not fully understand the entire issue.
Policies and practices should be evaluated with an eye toward removing all institutional barriers. For
example, to conduct an emissions reduction program most effectively, a company must be willing to expend
the necessary resources to fully integrate the operations of its various facilities departments. This implies
providing a vehicle to resolve conflicting needs between departments for limited resources. Additionally,
maintenance contractors should be required to account for refrigerant consumption as part of any new
contract. The environmental and financial benefits of investing resources in improving engineering,
construction, and maintenance practices might also be evaluated. Furthermore, corporate education of all
involved parties may result in personnel becoming motivated to improve practices or seek information on
emissions-reducing technologies.
Companies can take measures to become more vertically-integrated so that ideas developed by
internal O & M staff on new or improved emissions reduction methods will more likely to be relayed to people
who can effectively act on those ideas. As a result, problems that can be solved by simple design or
manufacturing changes will be corrected more quickly.
In addition to moving towards greater vertical integration, improving communications with
maintenance contractors is also a vital component of a corporate policy in the implementation of an emissions
reduction program. Obtaining specific knowledge of CFC refrigerant and equipment inventories and
refrigerant emission levels is a prerequisite to planning a program strategy; contractors can lend assistance
in this area. Companies that know the actual monetary costs of refrigerant emissions are in a good position
to justify expending resources to improve their situation. Furthermore, contractors that must provide regular
refrigerant recharging reports are likely to take steps to improve the emissions situation without prompting by
the client company.
Operating procedures sanctioned during the era of inexpensive refrigerants by persons in positions
to influence refrigerant consumption, (e.g., equipment manufacturers, system designers, installers) are
becoming outmoded in the new era. Efforts to improve policies and procedures may inspire the motivation
to solve these potential problems:
Lack of specific information on replacement refrigerant costs because these costs
can be buried in other operations costs;
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Lack of action on equipment manufacturers' part to improve product design to
reduce refrigerant emissions because communication between departments in
supermarket companies on equipment problems can be somewhat less than
optimal;
Lack of priority given to leak detection and repair by O & M departments because
cost-effectiveness of potential emissions reduction measures has not yet been
demonstrated within the company.
1.3 Options for Preventing Refrigerant Emissions
Supermarket companies ultimately can best reduce their refrigerant emissions by implementing a
variety of technological options, in addition to fostering greater coordination and communication between their
engineering, construction, and maintenance teams. Stressing accountability for refrigerant emission control
within each department is also extremely important to the success of an emissions reduction program. By
coordinating their efforts, supermarket personnel can reduce and prevent emissions in all facets of a piece
of refrigeration equipment's life cycle, including the initial design and construction and the subsequent
maintenance and repair of the equipment. Supermarkets can reduce CFC emissions specifically by simply
removing the CFC refrigerants from the systems and replacing them with alternative refrigerants. However,
supermarkets must always keep in mind the environmental implications of their refrigerant choices. For
example, the use of non-CFC refrigerant alternatives that have lower energy efficiencies than other viable
alternatives will result in higher levels of pollution generated at most power plants. In addition, some
alternatives have high direct GWPs, an issue that has already led to their restricted use in some foreign
markets.
This section describes quantitatively some options to prevent refrigerant emissions in the design,
construction, operation and maintenance of supermarket refrigeration systems. A quantitative evaluation of
these options is provided in Chapter 5.
1.3.1 Equipment Design and Construction
Refrigerant emissions can be controlled by following certain guidelines. If the design team
incorporates those guidelines into its specifications and if the construction department or contractor follows
those specifications as written, then supermarket refrigerant emissions can be reduced significantly. In
Chapter 5 of this report, estimates of refrigerant emissions reductions through implementing individual
technologies range from 3 to 25 percent.
1.3.1.1 Design
The engineering team occupies a position of considerable influence over refrigerant emissions yet
may receive little feedback on its designs from construction and maintenance personnel for various reasons.
If allowed to monitor the success of its existing designs in reducing emissions, the engineering team can help
prevent the occurrence of future refrigerant emissions.
Refrigeration systems that are designed for ease of service, operation and construction will more likely
be well built and maintained, thus reducing future service events and their accompanying refrigerant
emissions. Improved design practices will inevitably lead to smoother equipment operations, saving the
company money on refrigerant and energy costs.
Guideline 3, a publication of the American Society of Heating, Refrigerating, and Air-conditioning
Engineers (Reference: ASHRAE, 1990), provides solid, basic advice on system design, construction,
operation, and service practices. The content of this Guideline should be incorporated into engineering
practices and specifications as a critical component of an emissions reduction program.
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Feedback on system design problems received from the construction and maintenance teams can
be used by engineers to improve designs and specifications. Recurrent system component problems can
then be communicated to equipment manufacturers. Manufacturers can then begin to develop improved
equipment designs and a better-manufactured product. Providing this kind of feedback may enhance quality
assurance within the manufacturer's facilities, and eventually lead to less frequent equipment failures and
smaller levels of refrigerant emissions.
1.3.1.2 Construction
Construction departments and contractors can reduce refrigerant emissions from the equipment they
build by carefully following engineering specifications and providing feedback to engineering on design
improvements. By following exemplary construction practices, a climate of mutual respect between
departments can be created.
Since local codes regarding refrigeration installations rarely exist, some construction personnel may
be unaware of the special workmanship needs of these systems, and as a result, may "cut corners." In
addition, some technicians may be insufficiently trained in good installation practices. Some good practices
that construction staff can adopt include:
supporting and securing piping properly to minimize vibration and stress;
using brazing alloys of sufficient silver content to construct emissions-resistant
systems;
using dry nitrogen or other inert gas to minimize oxidation during brazing, greatly
reducing future maintenance problems resulting from contaminated refrigerant and
oil;
purging piping after construction with high pressure compressed air or nitrogen to
remove contaminants such as dirt and metal filings;
rigorously checking for leaks before allowing piping to be covered by walls or floors;
and
using flared fittings only when absolutely necessary.
Finally, the quality of the construction is also dependent on the quality of the materials used.
1.3.2 Operations and Maintenance Practices
Proper operations and maintenance practices are also critical to maintaining low levels of refrigerant
emissions. A comprehensive preventive maintenance program that includes thorough leak detection and
repair can spell the difference between a store with high emissions and one with minimal emissions. As
shown in Chapter 5 of this report, improvements in operations and maintenance practices can result in
emissions reductions of 5 to 40 percent.
Store operations and maintenance personnel have the responsibility to be aware of recurring
problems resulting in refrigerant emissions and to relay their observations to engineering and construction
personnel. If maintenance service is provided on a contract basis, potential abuses in performing unwarranted
maintenance work can be avoided by using "fixed-cost" maintenance and service contracts. These types of
contracts also provide an incentive to the contractor to minimize refrigerant leaks because contractors will net
higher profits if (1) direct costs of replacing refrigerant are reduced and (2) system repairs that are side-effects
of low refrigerant charges are reduced.
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Operations and maintenance technicians must have the proper training and the proper tools to
perform the tasks necessary to reduce emissions. Training requirements include;
• recognition of the importance of good preventive maintenance;
* ability to keep a good maintenance log;
~ ability to properly operate leak detection and refrigerant recovery devices; and
knowledge of low-emission refrigerant management techniques.
The tools service technicians must possess in the CFC transition era include portable recovery
devices and a portable leak detectors (cordless types are more likely to be frequently used). Moreover, these
tools can only be effectively utilized if sufficient time is provided to use them.
Maintenance and service technicians that value preventive maintenance are likely to devote more time
preventing repairs to avoid potential "midnight repair runs." One excellent method of reducing the frequency
of service events that conscientious technicians employ is to keep an updated maintenance log, recording
service events and refrigerant recharging events as they occur. By doing so, technicians can determine
whether the problems they encounter are systemic or random. They can then work on reducing the systemic
problems by determining if the fault lies with design or construction of the system or if increased preventive
maintenance is the solution to the problem.
Other store personnel can assist in the endeavor to reduce emissions as well. Quick checks of
refrigerant levels and telltale "oil-spotting" (indicating that oil and refrigerant are leaking) can be performed
by any person working in the store. Store personnel can also be trained to be aware of signs of low refrigerant
charges, such as poor temperature maintenance in display cases. Including non-technical store personnel
in the emissions reduction program is but one of a variety of options available to store owners to reduce
refrigerant emissions.
1.3.3 Non-CFC Refrigerants
Supermarkets that adopt the dual strategy of moving to alternative refrigerants and reducing leakage
from existing refrigeration systems realize a dual environmental benefit. Not only are these supermarkets
reducing emissions of gases implicated in ozone depletion, but of gases implicated in global warming as well.
New alternatives to replace ODS refrigerants have become increasingly more accepted as additional
successful field tests have been completed. However, many of these refrigerants are composed of blends
that may separate under certain circumstances. In the event of refrigerant leaks, the composition of these
blends may significantly deviate from the originally composition and have a resultant negative impact on
refrigerant cooling performance and energy efficiency.
Prior to the CFC phaseout, CFC-12 and R-502 had been used in supermarkets almost exclusively
because of their excellent properties as refrigerants at the temperatures required in supermarkets refrigerators
and freezers. CFC-12 had been commonly used in medium-temperature applications (0° F to 32° F [-18°
to 0°C] evaporator temperature) and R-502 in both medium- and low-temperature (-40° F to 0° F [-40° to
-18° C]) applications. Of all the non-flammable, non-toxic refrigerants developed in the pre-phaseout era,
CFC-12 and R-502 had the best properties for supermarket applications, operating under positive pressures
and with good energy efficiency. In addition, maintaining positive pressures is important to prevent air from
leaking into many kinds of refrigeration systems, but is critical in supermarket systems because of the large
number of potential leak sites. A low refrigerant charge caused by refrigerant leaking out does much less
damage to a system than a buildup of moist air caused by air leaking in.
The CFC phaseout forced the supermarket industry to quickly seek and implement alternatives to
CFC-12 and R-502, resulting in the temporary re-adoption of an old supermarket refrigerant, HCFC-22, for
both medium-temperature and low-temperature applications. Industry recognized that HCFC-22 was only an
interim solution, as this refrigerant also had an ozone-depleting potential (ODP), albeit a much smaller one
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than CFC-12 or R-502. However, industry had no choice but to proceed with HCFC-22 and HCFC blends until
non-ODS refrigerant alternatives were developed and placed on the market.
Contacts with several major refrigerant manufacturers revealed that at the time of this report many
refrigerant blends are available on the market for either new or retrofit applications; many more are
undergoing testing. The contacts also revealed that the single-component refrigerants HCFC-22 and
HFC-134a were available from numerous manufacturers, As mentioned previously, refrigerants listed on the
EPA SNAP list include HCFC-22, HFC-134a, HFC-227ea, ammonia, and the blends R-401 A, R-401B,
R-4Q2A, R-402B, R-404A, R-406A, R-407A, R-407B, R-408A, R-409A, and R-507. Following is a summary
of many of the refrigerants that have been developed for use in supermarket refrigeration applications by
various companies.
Allied-Signal
This manufacturer produces the HFC-based blend AZ-50, and also co-produces the HCFC-based
blends MP-39 and MP-66 with DuPont.
AZ-50 (R-507) is a blend designed to replace R-502 in new and retrofit applications.
MP-39 (R-401A) and MP-66 (R-401B) are retrofit substitutes for CFC-12.
Both of these blends are presently commercially available and are SNAP-listed.
DuPont
DuPont offers the blends MP-39, MP-66, HP-80, HP-81, and HP-62 for supermarket applications.
All of its blends contain HCFCs, except for HP-62, which contains HFCs only.
MP-39 (R-401 A) and MP-66 (R-401 B) are retrofit substitutes for CFC-12.
HP-80 (R-402A), HP-81 (R-402B) and HP-62 (R-404A) are retrofit substitutes for
R-502. HP-62 is also recommended as a refrigerant in new applications.
All blends are commercially available and SNAP-listed.
Elf Atochem
This company has developed three substitute blends for supermarket applications. Two of the blends
are based on HCFCs: FX-56 (R-409A), and FX-10 (R-408A). The other blend, FX-70 (R-404A) is based on
HFCs.
FX-56 is a blended substitute for CFC-12 for retrofit applications.
FX-10 is an HCFC-based retrofit alternative to R-502. FX-70 is an HFC-based
alternative to R-502 for new equipment; the refrigerant also has potential in retrofit
applications.
FX-10, FX-56 and FX-70 are all currently available and have been approved by the SNAP program.
Great Lakes
This company has developed and is presently testing a replacement for CFC-12 consisting of
HFC-227ea and HFC-152a. The blend will not be commercially available anytime in the near future.
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ICI Americas
This manufacturer has developed two HFC-based blends: Klea 407A (R-407A) and Klea 407B
(R-407B).
Klea 407A {the refrigerant formerly known as Klea 60) is a substitute for R-502 and
is designed to be used in retrofit applications only.
Klea 407B (the refrigerant formerly known as Klea 61) is also a substitute for R-502.
This blend is recommended for use in new equipment applications only.
Both of these alternatives are becoming widely commercially available. Both are SNAP-listed.
ICOR International
This company has developed R-4Q6A, a blended substitute for CFC-12. This refrigerant is intended
to be a drop-in replacement and may be substituted for CFC-12 without any hardware changes, according
to the manufacturer. The blend consists of HCFC-22, HCFC-142b, and isobutane. This refrigerant has been
approved for listing under EPA's SNAP program.
National Refrigerants
A blend made by Rhone-Poulenc, lsceon-69L (R-403B), is commercially available exclusively from
this distributor. This blend is a substitute for R-502 and is intended to be a "drop-in" replacement. It may be
substituted for R-502 without any hardware changes, however National Refrigerants recommends that the
system be "cleaned up" first by changing the oil and the filters prior to operating systems with this refrigerant.
The blend consists of HCFC-22, propane and perfluoropropane. This refrigerant has been evaluated for
listing under EPA's SNAP program and has been categorized as "proposed unacceptable" because other
refrigerants are available for this application that do not contain perfluorocarbons. (Reference: Federal
Register, September 1994)
1.3,4 Summary of Equipment-related Alternatives
Companies have three basic choices regarding the disposition of their existing equipment that
influence their choices of alternative refrigerants. They can:
maintain the equipment on CFCs as long as possible;
• retire their equipment, replacing it with non-CFC equipment; or
retrofit their equipment to alternative refrigerants.
The concerns regarding maintaining equipment on CFCs have been discussed in previous sections.
These include assuming the risk of not being able to obtain replacement refrigerant, incurring escalating costs
for replacement refrigerant, and potentially harming the environment through emitting refrigerant from the
system. These are all good reasons to make systems more leak-resistant if a company chooses to proceed
with this option for certain pieces of equipment.
Companies can also retire their equipment, either as a result of a remodel, equipment failure, or a
proactive CFC phaseout campaign. New equipment that uses alternative refrigerants is available for both
medium- and low-temperature applications. Alternative HFC-based refrigerants approved for use in new
equipment by some manufacturers include HFC-134a, R-507, and R-404A. HCFC-22-using equipment is
widely available for both low- and medium-temperature applications.
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Besides replacing refrigeration systems with new non-CFC systems, supermarkets also have the
option to continue to use their existing equipment by retrofitting it to various substitutes. Table 1.2
summarizes information regarding the alternatives to CFCs that can be used in new or retrofit supermarket
systems. Some substitutes described in the section above do not appear in the table because the refrigerant
is not commercially available.
1.3.5 Comprehensive Corporate Refrigerant Management
The supermarket companies that are most successful at reducing refrigerant emissions have become
that way as a result of careful planning involving all of the teams responsible for providing refrigeration to the
stores: engineering, construction, and maintenance. By coordinating the actions of these teams through
encouraging better communications between the teams, companies can ensure that their refrigerant emission
levels will continue on a downward trend.
To institute a comprehensive corporate refrigerant management program, a company must first take
stock of current practices. A thorough evaluation will determine which of its activities promote or at least do
not detract from the goal of reducing and eventually eliminating CFC refrigerant consumption. One good way
to improve the information collection is to provide incentives for personnel to become better informed about
the corporate refrigerant situation and the available emissions control options.
Other actions must be taken to move along an emissions reduction program. Company executives
controlling the management of supermarket facilities play a critical role in implementing an emissions
reduction program. Corporate executives can become more aware of the atmospheric effects and monetary
costs of their refrigerant emissions. Several methods to boost awareness include:
appointing a corporate refrigerant manager;
beginning a program to record amounts of and reasons for refrigerant consumption;
• improving the quality of communications between departments {for example, better
communications between operations and maintenance (O&M) personnel and
engineering and design (E&D) personnel could lead to low-cost, easy-to-maintain
equipment designs); and
gathering available information on the effects of CFC emissions on the stratospheric
ozone layer and distributing it to decisionmakers and implementation staff.
Personnel who work directly with the equipment such as equipment designers or installers may be
in a position to significantly influence a company's rate of refrigerant consumption directly. However, they too
must become aware of effective measures they can take to reduce emissions. Their awareness can be
improved through aggressive information collection. Materials presently available include:
• information available through supply houses;
information available through contractors;
information available directly from equipment and refrigerant manufacturers,
including advertising in trade publications promoting emissions-reducing
technologies;
EPA-developed information packets and fact sheets; and
articles in professional and trade journals.
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TABLE 1.2
REFRIGERANT ALTERNATIVES FOR SUPERMARKETS
ODS Refrigerant
Evaporator Temperature2
Non-CFC
Substitute
ODP3
GWP4
CFC-12
All
(Baseline)
1.0
7100
CFC-12
Medium and Low4
HFC-134a
0
1200
CFC-12
Medium
R-401A
0.033
1017
CFC-12
Low
R-401B
0.036
1116
CFC-12
Medium and Low
R-406A
0.052
1618
CFC-12
Medium
R-409A
0.044
1340
R-502
All
(Baseline)
0.332
4365
R-502
Low
R-402A
0.019
2648
R-502
Medium
R-402B
0.030
2252
R-502
Medium and Low
R-404A
0
3520
R-502
Medium and Low
R-407A
0
2990
R-502
Medium and Low
R-407B
0
3195
R-502
Medium and Low
R-408A
0.024
3295
R-502
Medium and Low
R-507
0
3600
CFC-12, R-502
Medium and Low5
HCFC-22
0.05
1600
2 A medium temperature evaporator is required to refrigerate fresh foods. A low temperature
evaporator is required to refrigerate frozen foods.
3 ODP denotes the refrigerant's Ozone Depletion Potential, referenced to CFC-11. GWP denotes the
refrigerant's Global Warming Potential, based on a 100 year time horizon and referenced to C02 as a
baseline (value of 1.0). Hydrocarbons are assumed to have a GWP of 3.0. (Reference; Derived from
CAAA, Section 602, 1990; and UNEP, 1992.)
4 Retrofits of low-temperature CFC-12 systems to HFC-134a may result in unacceptable losses in
cooling capacity (up to 30 percent).
5 Retrofits of low-temperature R-502 systems to HCFC-22 may result in unacceptable losses in cooling
capacity (up to 20 percent).
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After some evaluation, corporate executives may need to resolve cross-departmental problems to
achieve effective refrigerant management Furthermore, additional internal funds may need to be redirected
to facilities departments for use in reducing long-term operating costs through an emissions reduction
program. The large potential impact of reduced operating costs on the traditionally low profit margins of this
competitive business may justify such an investment. In addition, such a program might be turned into
another advantage for the company as well. A high-visibility "green grocer" campaign could be launched
which promotes the company's efforts in reducing ODS and greenhouse gas emissions through a refrigerant
emissions control and CFC refrigerant phaseout program and an energy use reduction program.
Facilities executives may need to adopt other creative methods to gain approval and funding for any
new programs they wish to implement. These tactics may include:
implementing pilot projects to demonstrate the cost-effectiveness of new
technologies and new operating procedures;
emphasizing the potential for store disruptions or high refrigerant costs if measures
to reduce emissions are not taken;
emphasizing the strategic competitive importance of the technologies; and
building a refrigerant consumption reduction team including people in the legal,
financial, environmental, engineering, construction, and maintenance departments.
By taking initial small steps to get quick results and building a team involving important
decisionmakers, program managers have a better chance of success than attempting to conduct the program
alone.
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CHAPTER 1 REFERENCES
1. Clean Air Act Amendments. U.S. Public Law 101-549, Title VI, Section 604 (Phaseout of Production
and Consumption of Class I Substances). November 1990.
2. Clean Air Act Amendments. U.S. Public Law 101-549, Title VI, Section 608 (National Recycling and
Emission Reduction Program). November 1990.
3. Federal Register. Volume 58, No. 92, pp. 28660-28734 May 1993.
4. Clean Air Act Amendments. U.S. Public Law 101-549, Title VI, Section 612 (Safe Alternatives Policy).
November 1990.
5. Federal Register. Volume 59, No. 53, pp. 13125-13126. March 1994.
6. Federal Register. Volume 59, No. 165, pg. 44252. August 1994.
7. Robert E. Bittner, II, P.E., Giant Food. Internal presentation to Giant Food maintenance and
engineering staff. 1992.
8. The American Society of Heating, Refrigerating and Air-conditioning Engineers. Guideline 3 -
Reducing Emission of CFC Refrigerants in Refrigeration and Air-Conditioning Equipment and
Applications, 1990.
9. Federal Register. Volume 59, No. 185, pg. 49116. September 1994.
10. Clean Air Act Amendments. U.S. Public Law 101-549, Title VI, Section 602 (Listing of Class I and
Class II Substances). November 1990.
11. United Nations Environmental Programme. Climate Change: Supplementary Report to the IPCC
Scientific Assessment, pg. 56. 1992.
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CHAPTER 2
Case History - Hannaford Brothers Company
Hannaford Brothers Company, a chain of 95 supermarkets operating in northern New England and
upstate New York under the trade names Shop 'n Save, Sun Foods, and Martins, has adopted a proactive
stance on the CFC phaseout issue. The company's approach to reducing CFC emissions from its
refrigeration systems consists of two parts. First, the company is removing CFC refrigerants from its systems
by retrofitting its existing stock of refrigeration equipment to accommodate alternative refrigerants. Second,
the company is in the midst of a program to significantly reduce leakage of all types of refrigerants from its
refrigeration equipment.
The company's goal was to eliminate its use of all CFCs by September 1994. The company has
already eliminated its purchases of virgin CFC refrigerants as a result of its CFC phaseout program. Any
replacement refrigerant required by the remaining CFC systems now comes from the store of refrigerant
recovered during retrofit activities. The company's CFC phaseout program has proceeded smoothly. CFC-12
was eliminated from all the company's refrigeration systems by the end of 1993 through retirement or retrofit
of the CFC-12 refrigeration equipment. The company then pursued a phaseout of R-502. As of May 1994,
this refrigerant has already been totally eliminated from eight stores, with retrofits partially complete in 39 other
stores.
Consumption of R-502 and alternative refrigerants has been reduced by an aggressive leak detection
and repair program which augments the company's regular preventive maintenance program. As a result,
Hannaford has reduced refrigerant emissions to near-zero in many stores. The company's refrigerant
emissions reduction program has also reduced net operating costs. The program stresses involvement and
accountability by all departments responsible for the stores' refrigeration systems including store design,
construction, and maintenance. The company's outside maintenance contractors have also been made
accountable for the refrigerant used in the stores.
The head of the company's CFC phaseout and leak reduction program is Tom Mathews, Hannaford's
Facilities and Energy Manager. It is his belief that the company's efforts to reduce refrigerant emissions have
given them a competitive advantage - first, because the company's environmental actions are appreciated
by their customers and, second, because the operating costs have been reduced by requirements for less
replacement refrigerant.
2.1 Engineering the Emissions Out
Refrigerant emissions are known to be the result of both regular operating leakage and catastrophic
releases. Hannaford controls many of these emissions through regularly scheduled leak inspections and
prompt repairs. Once equipment is built, leaks can only be reduced by inspection and repair. However, by
careful design from the beginning, equipment can be configured to eliminate factors or components which in
standard systems would be prone to catastrophic leaks.
When CFC refrigerants were low-priced and thought to be environmentally harmless, Hannaford
stayed competitive with low-first-cost refrigeration system designs. Over time, however, Hannaford has
modified its design practices. In developing its program to "engineer the emissions out," Hannaford carefully
examined practices where it could most effectively reduce its leaks. It identified several major factors
contributing to refrigerant leakage:
System designs that required large numbers of joints and connections, each a
potential leak site,
The hot-gas method of defrosting cooling coils which created many opportunities for
leaks to occur,
Construction specifications that did not ensure clean leak-free systems,
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Equipment manufacturers that did not offer low-emission designs,
The maintenance department which had no regular leak detection and repair
program, and
Maintenance contractors that operated under contracts that indirectly discouraged
efforts to control refrigerant leakage.
2.2 Loop Piping Designs
In decades past, Hannaford engineers had used conventional designs in the construction of store
refrigeration systems. Although effective, these conventional designs shared a common flaw: each
refrigerated case or cooler box required a set of refrigerant pipes running from the common header pipes in
the mechanical room to the cooling coil in the refrigerated space. For the average Hannaford store, this
meant that installation of 50 to 60 sets of pipes was required to provide cooling to all of the refrigerated
spaces. Each set required a substantial number of connections and joints and consequently included potential
sites for a leak to occur.
In an effort to reduce the number of long pipe runs and correspondingly large number of connections,
Hannaford began in 1985 to implement "loop piping." The innovative system design required far fewer joints
than conventional designs. In essence, loop piping entailed extending two common pipes from the
compressor racks out into the store area to all of the refrigerated systems. The inlet and outlet of each cooling
coil was then connected to the common pipes with a short run of connecting piping. Moreover, the common
pipes, with their larger size and sturdier construction, tended to be much more resistant to breakage from the
movement of the building as it settled than the smaller pipes used in former designs. Hannaford estimates
that loop piping saved the company about two-thirds of the total piping length and two-thirds of the fittings.
In addition, refrigeration installation costs decreased about 30 percent compared to conventional designs.
2.3 No More Hot-Gas Defrost
The company had been using the hot gas discharged from its compressors to defrost its cooling coils.
Although this method worked quickly, it had several drawbacks.
The method required the compressors to operate with high discharge pressures for
defrost purposes year-round instead of allowing the discharge pressures to fall with
the outside air temperature in the cooler months, preventing the company from
capturing significant energy savings.
Additional components and piping were required to install a hot-gas defrost system,
increasing the number of potential leak sites. In addition, this type of defrost made
loop piping more difficult.
Thermal expansion, contraction and stress degradation of valves, piping, and
connections were a consequence of the characteristic sudden changes in
temperature, eventually resulting in leaks.
Over time, Mr. Mathews' objections to the use of hot-gas defrost grew. He discontinued its use after
observing that, on average, releases of refrigerant of at least 100 pounds were occurring about four times a
year per parallel rack. Mr, Mathews instead began to specify electric resistance heaters to defrost the
company's freezers. The electric defrost method proved to be more effective than the hot-gas method and
required less refrigerant charge. Hannaford also began to institute a demand-defrost scheme that eliminated
unnecessary defrost cycles. Overall, Hannaford's operating costs averaged 15 to 18 percent lower for the new
defrost method.
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2.4 Improved Construction Practices
Hannaford's engineering department has instituted many changes to improve the quality of the
refrigeration equipment installations. To prevent refrigerant leakage, the company mandates rigorous
pressure testing of the refrigeration systems following their construction, ensuring system integrity. To reduce
the presence of contaminants left in the systems after installation and increase the strength of the piping
connections, the engineering specifications were also changed to include:
mandatory use of nitrogen or other inert gas during brazing operations to prevent
internal oxidation of the piping from contaminating the systems,
mandatory installation of filters upstream of all expansion valves to protect the valves
from clogging with any particulate left in the system, and
mandatory use of solder containing at least 15 percent silver to ensure strong, leak-
resistant connections.
Hannaford's strategy to prevent unnecessary service expenditures has resulted in reduced operating
costs with only marginally increased construction costs. Its philosophy is that by building clean, dry, and tight
refrigeration systems to start with, it can concentrate its operations and maintenance resources on
inexpensive preventive maintenance rather than on expensive repairs.
2.5 Improved System Component Designs
As an additional part of its program, the company worked with its equipment manufacturers to develop
lower-emission products. Hannaford now requires that display cases be equipped with expansion valves with
sweat-type connections instead of flare-type because the company has had several problems with leaky flare
connections on expansion valves. Compressor racks are now ordered with special steel capillary tubing for
pressure controls instead of copper, because steel has better resistance to stress failure, abrasion, and
breakage.
Hannaford's choice of air-cooled condensers is also significant. The company requires that all
condensers purchased be modular units with tubing bundles less than five feet long, have side-mounted
tubing headers, and have large, low-tip-speed fans. Condensers of this type have fewer problems with
emissions because chafing of the condenser tubing is reduced. In addition, condenser fan mountings have
less chance of shearing off from vibration and puncturing the condenser tubing.
Hannaford has obtained good results by maintaining open lines of communication with its equipment
manufacturers. Mr. Mathews commented that in his experience, manufacturers can often be persuaded to
improve their products, particularly when pushed by customers that constitute at least one percent of their
business. Given Hannaford's significant purchasing power and the competitive refrigeration systems
components market, manufacturers do listen when Hannaford has a suggestion.
2.6 Improved Maintenance Practices
Hannaford has been taking steps to improve its maintenance program since 1987. The company
realized that in order to effectively reduce its refrigerant emissions, the people performing maintenance on
the stores would have to be committed and enthusiastic participants in the program. Crucial to improving
Hannaford's maintenance program was getting across to its mechanics that a zero-emissions store was not
only practical, but practicable.
The implementation of EPA's no-venting rule and refrigerant recycling regulations added some
urgency to the situation. Upon the issuance of the regulations, Hannaford's management reemphasized the
need to reduce refrigerant emissions to maintenance staff. The company believed that it could eventually
reduce refrigeration system problems to the point where its increasing number of stores could be maintained
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by the same number of mechanics for the same labor-hours. In the end, the company's belief was confirmed.
By performing leak detection and repair as a regular and important part of their job, Hannaford's mechanics
were able to reduce total maintenance costs. Although regular labor hours remained the same, "middle-of-
the-night" repair runs and nuisance calls were significantly reduced, and replacement refrigerant costs were
reduced as well. Mr. Mathews also reports that the company's systems now run better and more efficiently.
Hannaford's maintenance mechanics are required to perform four to eight hours of leak detection and
repair per store per month. In addition, one overall leak inspection of all systems is required each week. Of
those hours, the mechanics spend 90 percent of the time searching for and gaining access to leaks.
Hannaford eased its mechanics' leak-checking burden considerably by purchasing battery-operated leak
detectors. Leak detectors that required electrical cords had proved to be cumbersome and were not well
utilized. Hannaford's new leak detectors are capable of detecting CFCs, HCFCs, and HFCs, important for
a company that plans to invest heavily in HFC-based technology.
The remainder of the time is usually spent correcting problems with flanged and flared connections.
This usually entails tightening valve packings and replacing seals. Occasionally, mechanics will find a leaking
brazed connection. Although very few brazed connections leak refrigerant, when located, they must be
removed and replaced, requiring about two hours of a mechanic's time. In aggregate, however, the
mechanics spend far more time reducing leakage from non-brazed connections.
Hannaford's mechanics spend a great deal of time trying to prevent catastrophic losses of refrigerant.
This entails careful inspections of the high-temperature, high-vibration locations in the system, where
catastrophic refrigerant emissions are most likely to occur. In particular, the compressor racks are carefully
inspected for loose clamps, excessive vibration, and tube chafing. These kinds of conditions may precede
a major release of refrigerant.
2.7 Incentives for Contractors
In its review of its refrigerant management methods, Hannaford scrutinized the way its maintenance
contractors operated. The company began to require that contractors provide a periodic refrigerant
replacement report and discovered that maintenance contractors operating under service-only contracts that
allowed them to bill Hannaford for replacement refrigerant tended to have high refrigerant consumption, while
contractors operating under fixed-cost service-and-preventive-maintenance contracts had much lower
refrigerant consumption.
Hannaford consequently began to specify that all new contracts be of the fixed-cost service-and-
preventive-maintenance type. Now that its contractors have the incentive and the means to keep refrigerant
in the systems, the company is realizing significant financial benefits from its reduced replacement refrigerant
costs. Last year, Hannaford observed significant reductions in refrigerant consumption for those contractors
that were switched over to fixed-cost contracts. Moreover, these consumption reductions were obtained in
a very cost-effective manner.
2.8 Program Results
As a result of its comprehensive refrigerant management program, Hannaford has reduced its
consumption of all new refrigerants by 44 percent from last year and consumption of R-502 by 54 percent.
Overall, Hannaford has reduced its total refrigerant consumption by 80 percent in eight years, while at the
same time doubling its number of systems requiring refrigeration.
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CHAPTER 3
Case History - Shaw's Supermarkets
Shaw's, a chain of 88 stores operating in four states in the New England area has generated some
significant results in its mission to reduce refrigerant emissions from its stores. The company is working
diligently to streamline its policies and programs to reduce refrigerant emissions and resulting dependence
on market supplies of CFCs,
Shaw's benefits from its affiliation with the supermarket trade group, the Food Marketing Institute
(FMI). John Seaburg, Shaw's Vice President of Engineering and Construction, previously was Chairman of
the Energy and Technical Services Committee and is currently active on the Alternative Refrigerants Task
Force. Joining FMI, according to Mr. Seaburg, is a good way to become better informed about state-of-tfie-art
methods of managing both CFC and non-CFC refrigerants and equipment, and the latest new products and
developments in the industry.8
3.1 An Emissions Reduction Program
In the early stages of the development of his company's CFC elimination program, Mr. Seaburg
quickly realized that by attempting to retrofit or replace all of Shaw's CFC refrigeration equipment with HCFC-
22 technology, the company would incur high costs in the first years of the program. Shaw's determined that
a program to immediately reduce leakage from the chain's refrigeration systems in conjunction with a long-
term program to retrofit and replace the equipment would be more cost-effective. In addition, by starting an
emissions reduction program immediately, the company gained several advantages.
The company saved the cost of retrofitting many of its pieces of existing refrigeration
equipment by both reducing CFC consumption of the equipment and using
refrigerant recovered during retrofits to service the equipment. This was the optimal
strategy for equipment that was still useful, but was not a good candidate for retrofit,
as its life could be prolonged inexpensively until natural retirement.
The company gained additional time to formulate its policy on long-term alternative
refrigerants while awaiting the development and testing of long-term refrigerants.
At the time, many refrigerant alternatives were still under development and most
non-CFC equipment was not available.
The company blunted the effects of the escalating prices of replacement refrigerant
by reducing demand for replacement refrigerant.
• The company prepared for possible future regulations regarding levels of emissions
from supermarkets by developing methods to reduce emissions.
In addition to moving to alternative refrigerants cost-effectively, Shaw's had three other objectives for
its emissions reduction program: first, complying with regulations on refrigerants; second, ensuring product
integrity to keep customers coming to the stores; and third, improving the overall quality of the facilities
departments in general.
Shaw's needed its refrigerant consumption to match its available supply of refrigerant to assure
uninterrupted equipment operation. The company planned to accomplish its goals through "the five Rs," by;
6 FMI's Energy and Technical Services Committee has published some CFC phaseout guidelines for
supermarket facilities departments entitled 1994 FMI Alternative Refrigerant Guidelines. Updates are
added as new information becomes available.
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reducing refrigerant leaks to the atmosphere through leak detection and
maintenance programs,
recovering refrigerant during equipment service, retrofit, and retirement,
• recycling refrigerants within the business, saving money over the cost of virgin
refrigerant7,
reclaiming recovered refrigerant of unknown quality to ARI Standards through a
trusted reclamation company, and
reusing refrigerants as much as possible.
Shaw's assessed its existing infrastructure to determine what practices and conditions could be
improved to reduce or prevent refrigerant emissions. It determined that improvements could be made in all
of its facilities departments, including engineering, construction, and maintenance. The company also
believed that purchasing a computer program that could monitor its refrigerant consumption and log
maintenance events could help minimize refrigerant emissions.
3.2 The Maintenance Manager
The company already had been recording its CFC consumption on an individual store basis.
However, with the availability of refrigerants becoming an increasing concern for the company, Shaw's
recognized the need to track refrigerant usage at the system level. It could then concentrate its efforts on both
its highest-leaking stores and systems, maximizing its available resources. The company also recognized
the need to monitor its service events to better troubleshoot refrigeration system problems. Shaw's
consequently located and enlisted the aid of a company that had developed a computer program that
performed both of these functions.
The program's capabilities also extended to forecasting refrigerant needs, helping the company plan
its equipment conversions and replacements so that its overall costs from new refrigerant purchases could
be reduced. The initial cost for the program seemed high, at $7,500 for a single terminal and $30,000 for a
networked system of five terminals. Shaw's opted for a networked systems, and it paid for itself in less than
one year. The program required no additional labor to update its database because it interfaced directly with
Shaw's accounting program. The information the accounting clerks had been entering from service invoices
into the accounting system for years now had a dual function.
The program was designed for companies with multi-site operations, such as grocery chains and
could track refrigerant movement and leakage by location. At any time, an operator could log on to the
database and query the program on various topics, such as equipment servicing histories and refrigerant
recharging histories. Furthermore, the operator could prioritize database searches by type of event. This
capability allowed Shaw's to troubleshoot and monitor its equipment from the office to optimize its service and
preventive maintenance strategies.
3.3 Underground Piping
Shaw's had been experiencing problems with piping that was located in exposed spaces. When
Shaw's piped all of its systems above ground, piping had occasionally been damaged by store personnel in
the normal course of store operations. In an effort to prevent possible risk to employees and damage to
unprotected piping and connections, Shaw's began the practice of locating refrigerated system piping in
trenches under the floor slab. As a bonus, the installation cost of locating piping underground has so far been
less than the cost of locating the piping overhead.
7 Excise taxes do not apply to recycled refrigerant.
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However, locating piping underground presented a potential problem to maintenance personnel, as
any leakage from underground piping or connections could require demolition of the floor slab to locate the
leak. Shaw's came up with a solution to both increase access to the piping and decrease the probability of
a leak. The company specified that any tubing located underground must be of the soft-drawn type. This type
of tubing could be installed in 50 foot continuous lengths. To ensure the accessibility of the required
connections, the company specified for service pits to be constructed every 50 feet as well.
3.4 Stationary Leak Detectors
As a further control on its refrigerant emissions, Shaw's also began to monitor in-store air for the
presence of refrigerant, employing stationary leak detectors in many stores. The manufacturer of Shaw's
refrigeration controller and energy management system (EMS) offered this capability as an option on its
equipment for an additional five percent premium on the price, and Shaw's accepted its offer. Shaw's now
had the capability to monitor refrigerant leakage continuously. Each system is set up to monitor eight points
in the stores - three in the compressor room, four in the main pits, and one in the duct that returns air from
the store to the air handler. Whenever a sensor detected a significant leak, it sent a signal to an alarm
company, who in turn contacted Shaw's maintenance department.
Shaw's needed to periodically adjust the sensitivity of the leak detectors because they gave off
numerous false alarms at the outset. For instance, soon after installation, the leak detectors were sensing
small quantities of naturally-occurring methane in the backfill of the main pits and sounding an alarm. Fine-
tuning of the system resulted in fewer false alarms, but the system did require some time to calibrate.
The installation of these units has resulted in significant benefits for Shaw's. In one incident, one of
Shaw's contractors insisted that a problem existed with one of the refrigeration systems, but that it was not
due to refrigerant leakage. Because Shaw's had this remote monitoring capability, it was able to show
evidence to the contrary. In addition, if refrigerant is emitted from a leakage point prior to the leak becoming
catastrophic, the system can alarm the maintenance department immediately so that maintenance personnel
can repair the leak and avoid a major refrigerant loss.
3.5 Charge Reduction
To reduce the impact of catastrophic leaks, Shaw's makes efforts to reduce the system refrigerant
charge size in its designs. The company employs four design features that reduce charge size. These
features are:
remote headers,
heat reclaim pump-out,
* split condensers, and
condenser bypass.
Shaw's was aware that it had been using large amounts of piping to construct its systems. But after
seeing an eye-opening report on the actual length of piping and number of connections required to build a
conventionally-designed store, the company was determined to improve its design practices. Shaw's decided
to reduce the overall piping length by reducing the number of pipes coming out of the compressor room and
extending the main suction and liquid lines out into the store in locations central to the systems serviced.
Remote headers were then attached to collect and distribute refrigerant for short branch lines serving
individual refrigerated spaces. Not only did this design reduce refrigerant charge by approximately 15 percent,
but Shaw's contractors reported that it saved 10 to 15 percent on piping installation costs.
In examining its practices, the company identified another way to improve on conventional designs.
With its previous design, after completion of a heat reclamation cycle, refrigerant had remained stagnant in
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the heat reclaim coil and piping. The improved design called for the addition of an electrical circuit and
components to pump the refrigerant out of the heat reclaim system after cycle completion, This modification
helped maximize the utilization of refrigerant in the system.
In the winter months, when refrigerant requirements were maximal and the compressed refrigerant
was more easily condensed back into liquid and required fewer condenser tubes to reject the heat of
evaporation and compression, Shaw's took the opportunity to install apparatus to valve off sections of the
condenser, thereby saving an additional 15 percent of the charge.
Another wintertime savings opportunity was the fact that it occasionally got so cold that the refrigerant
condensed entirely back to liquid within the heat reclamation coil. A system was designed to sense this
condition and then valve off and pump the refrigerant out of the condenser. This feature allowed Shaw's to
reduce charge size by an additional five to 10 percent.
3.6 Eliminating Capillary Tubes
In its quest to further improve its operating procedures, Shaw's investigated the occurrences in which
it had lost the most refrigerant from its systems. The company observed that failed capillary tubes were
frequently at fault, with five to ten percent of these devices leaking significant amounts annually. These tubes
were subject to large amounts of vibration, being typically mounted in close proximity to the compressors.
If they failed, the entire refrigerant charge would be lost within minutes.
The company began to investigate where it could eliminate the need for capillary tubes, it found that
in many instances, other technologies could be used. For example, electronic oil and pressure sensors could
be used, thereby eliminating the need for a pneumatic-type control that required capillary tubes to transmit
pressure to a controller. Not only could electronic controls greatly reduce refrigerant emissions, they could
also act as inputs to the EMS, allowing remote monitoring of system conditions, a great help in remote
troubleshooting.
In applications where the company could not find suitable electronic substitutes, it applied a
technology used in aerospace applications that was a good alternative to capillary tubes. This technology was
a type of polymer hose supported on the outside with braided steel hose. This product was not only compliant,
so that it couid make the sharp bends required by its application, but vibration- and abrasion-resistant as well
because of its tough steel outer shell. Although the polymer inner hose was slightly permeable to refrigerants
on the order of a few ounces per year, it could prevent virtually all emissions resulting from capillary tube
failures.
3.7 Improving Maintenance
Shaw's had already been recovering most of its refrigerant during service operations by either
pumping refrigerant into the receiver or into another compressor rack in the mechanical room. After the
issuance of the EPA's recycling regulations, however, Shaw's recovery program became even more efficient
as the company purchased portable refrigerant recovery devices for all of its service mechanics.
Shaw's had found that the best way to reduce the costs of a leak reduction program was to coordinate
the activities of the in-store personnel with the maintenance personnel. For example, to check whether an
expansion valve or cooling coil in a case is leaking, product must first be removed from the case to access
the refrigeration components. Shaw's tries to schedule its leak detection activities to coincide with routine
case cleaning to minimize labor requirements.
The maintenance department convinced in-store personnel to let it handle all operational problems
with the cases and cooler boxes by promising and delivering quick call response times. If a case is severely
frosted, store employees now know not to attempt to remove the ice with an ice pick, but to call maintenance
immediately.
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When Shaw's must contract out service work to maintenance contractors, it chooses the company
from a select list of preferred contractors who have all been specially trained. The company expended great
effort in educating its contractors to do things meticulously and properly. This effort includes regular formal
instruction on procedures and schedules for service items, e.g., refrigeration system oil changes and
refrigerant leak detection and repair. The company urges the contractors to work towards a fixed budget and
to do everything possible not to exceed the budget
3.8 Results of the Program
Shaw's CFC phaseout program is doing quite well due to the success of its emissions reduction
program. To date, Shaw's has two stores in which it has eliminated ozone-depleting refrigerants from all of
the refrigeration equipment, and twelve stores in which CFC-12 has been completely eliminated.
The company has reduced total chain-wide consumption of CFCs by 44 percent of its 1988 levels,
at the same time adding about eight new stores each year. Its refrigerant recovery, recycling and reclamation
program has allowed it to reuse over 3,000 pounds* of refrigerant since 1990. On average, annual refrigerant
purchases have been reduced 18 percent by using recycled product. At this year's current cost per pound,
this amounts to about $45,000.
Finally, according to its computerized maintenance manager and refrigerant tracking program, Shaw's
has reduced its annual refrigerant system leakage by 29 percent (or approximately 6,000 pounds) over the
last two years.
* 1 lb = 0.454 kg
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CHAPTER 4
Case History - Jitney-Jungle Stores of America
Jitney-Jungle Stores of America, a chain of 108 stores operating in six states throughout the South
has launched an ambitious program to reduce its consumption of CFCs and other refrigerants. The
company's approach includes a comprehensive refrigerant leak detection and repair program as well as a
rapid transition to alternative refrigerants through equipment conversion and replacement The company has
been removing CFC refrigerants from its systems by converting its existing stock of refrigeration equipment
to accommodate alternative refrigerants and replacing older, leakier, inefficient equipment with state-of-the-art
non-CFC equipment.
In 1991 James Riley, Jitney-Jungle's Vice President of Engineering began to collect information on
his options to reduce and eventually eliminate refrigerant consumption in Jitney-Jungle's stores. He formed
a team of advisors including people with good knowledge of the company's existing systems as well as people
with good knowledge of the new refrigerant and equipment alternatives. The team began with some test
conversions to HFC-134a, R-402A, and R-404A, and quickly built up the confidence to convert an entire store
to HFC-134a and R-402A. Using the experience gained from the first non-CFC conversions and installations,
the company began to implement a program to eliminate its purchases of virgin CFC refrigerants by the end
of 1995, using only the store of refrigerant recovered during conversion activities to satisfy the needs of its
remaining CFC systems.
4.1 Refrigerant Conservation Opportunities
To accomplish its goal of eliminating all purchases of virgin refrigerant, the company devised a
program to conserve refrigerant by reducing emissions resulting from all phases of its operations. It first
identified and assessed those practices in engineering, service, and maintenance where opportunities existed
to make practical, effective changes. It identified several factors directly contributing to refrigerant emissions:
A commonly-used receiver design that required larger-than-neeessary amounts of
refrigerant, resulting in extra emissions in the event of a catastrophic failure;
A commonly-used refrigerant expansion valve design that resulted in predictable yet
preventable refrigerant emissions;
System designs and maintenance practices that resulted in conditions leading to
high system operating temperatures and pressures, making systems more
susceptible to failure;
Service operations in which mechanics were sometimes too busy to conduct
effective leak detection and repair, and were thus occasionally forced to settle for
topping off systems with refrigerant to keep the stores operating; and
Installation practices in which systems were sometimes left without optimal
component-isolation or refrigerant access facilities.
4.2 Vertical Full-charge Surge Receivers
In its assessment, the company questioned why its compressor racks were always furnished with
horizontal flow-through receivers instead of vertical surge receivers, which had been available for many years.
The company asked its rack manufacturers to rework their arrangement of rack components so that vertical
receivers could be used.
Vertical receivers offered three benefits over horizontal receivers, because of the latter type's smaller
horizontal area. First, and most importantly, vertical receivers required smaller quantities of refrigerant to
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maintain the same depth of liquid as a horizontal receiver. Second, vertical receivers consumed less floor
space, allowing for a more compact arrangement of system components, and thus a smaller compressor rack.
Third, by installing a vertical receiver in a "surge" arrangement instead of a "flow-through" arrangement, free
subcooling of the liquid refrigerant that occurred in the winter months could to be preserved, as less mixing
occurred between the newly-condensed, cold refrigerant and the warmer refrigerant stored in the receiver
inside the store, thereby saving energy.
4.3 All-sweat Thermostatic Expansion Valves
After becoming aware of the problems it was having with refrigerant leaks from its flare-type
thermostatic expansion valves, the company decided to investigate the use of the newly-available sweat-type
(brazed) valves. After some initial successes with the technology, the company decided to require that all new
display cases be equipped with sweat-type expansion valves instead of flare-type. Although this design made
it more difficult to remove expansion valves for service reasons, the company has noticed a very significant
reduction in emissions from this particular component In addition, the brazed valves include external
strainers in order to make the valves easier to clean in the event that particulate matter clogs the valve.
4.4 Improved Mechanical Room Conditions
In discussions between the engineering department and the maintenance department, it was
determined that systems which operated with the highest pressures and temperatures were among those
systems with the most maintenance problems related to refrigerant emissions. Therefore, an effort was made
by both engineering and maintenance personnel to keep pressures and temperatures down.
Engineering personnel made special efforts to increase ventilation, ensuring that compressor room
ventilation was adequate to control heat gain. In addition, the largest size compressor head cooling fans
available were specified to be installed on each new compressor to be put into service as well as those
compressors which had problems with overheating. Departing from standard industry practice, head cooling
fans were specified for compressors operating in the medium-temperature range, reducing the amount of heat
to which all of the stores' systems were subjected. In addition, monitoring sensors were installed in those
stores containing electronic refrigeration controller/monitors so that Jitney-Jungle could obtain detailed
performance data on systems, such as temperatures and pressures at various key points.
Maintenance personnel took special care to make heat transfer from the systems as efficient as
possible, ensuring that condenser surfaces were cleaned regularly, ventilation fans and controls were
operating properly, and systems were monitored more closely to detect heat-related problems. During
regularly-scheduled major inspections equipment operations were restored to original engineering
specifications to optimize the utility of the heat- and pressure-controlling design features.
4.5 Improved Service and Maintenance Program
The CFC phaseout has been a time of tremendous change for the company's maintenance
department. For environmental and financial reasons, the company needed to conserve its existing refrigerant
supply. A refrigerant tracking system was implemented and leak detection and repair practices were improved
to augment the company's existing preventive maintenance program. As a result, the company believes it
can reduce refrigerant emissions to insignificant levels by the end of 1994.
Since November 1993, construction and maintenance personnel have been responsible for helping
maintain a refrigerant accounting log by filling out a short form at the company's centralized depot before
picking up refrigerant to replace refrigerant used during service operations. The form reflects all charging
events, and includes the date, the quantity used, the reason for recharging, and the location of the leak, if any.
In order to keep the stores' refrigeration systems operating while reducing refrigerant emissions levels,
additional maintenance personnel were hired. As a result, each mechanic can now conduct 20 to 30 hours
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of leak-checking and repair per month. Mr. Riley remarked that the biggest issue he faces in continuing his
emissions reduction program is not retraining his staff, but focusing on those procedures that conserve the
most refrigerant. As a result of his efforts, the mechanics now employ several methods to control system
ieaks, including fluorescent dyes, soap-and-water bubbling solutions, and halogen torch-type leak detectors.
To further aid in locating and eliminating emissions, the company has purchased electronic teak detectors for
all of its mechanics and refrigerant recovery units for all of the maintenance trucks as well.
Two mechanics have been assigned to a leak elimination task force to perform leak checks and
repairs full-time, with two more to be added to the task force soon. To reduce leaks in a single store, one of
the mechanics on the task force typically requires one to two days to leak-check and complete repairs on a
store containing dedicated single-compressor refrigeration systems, and two to three days on a store
containing parallel compressor racks. Indications are that the increased operating costs for the preventive
maintenance efforts have been more than offset by the reduced requirements for replacement refrigerant.
4.6 Installation of Isolation and Access Valves
To aid in the recapturing of refrigerants, the company has begun to specify the installation of isolation
and access valves on all large or frequently-serviced components, such as condensers, heat reclaim coils,
solenoid valves, and filters. Now when repairs are conducted on these components, refrigerant charges can
be isolated within the component and accessed for removal, significantly reducing both downtime for
recovering the refrigerant charge and any emissions associated with managing the recovery of a large amount
of refrigerant. Bypass piping is now typically installed around filters so that filter cores can be replaced without
removing systems from operation.
4.7 Reducing Emissions during Conversions
An important consideration that has surfaced in converting to the new refrigerants and lubricants is
material compatibility. For example, some valves that were leak tight with the original CFC refrigerant and
mineral oil were found to leak with R-402A. This problem involved only a single model made by a single
manufacturer, but it did heighten the company's awareness of the differences between the old and new
refrigerants and lubricants. The leaky valves were replaced, and the problem was solved. Typically, besides
the lubricant and filter/driers, the company does not need to replace any of its refrigeration system
components during conversions for refrigerant compatibility reasons.
Another concern was the moisture-absorbing characteristics of the polyol ester lubricant used with
some of the new refrigerants. Typical practices used for charging mineral oil systems could not be applied
when using the new lubricant, since the polyol ester lubricant would quickly absorb moisture from exposure
to the air. This condition could eventually have led to significant emissions resulting from system damage
from moisture contamination. The way the company solved this problem was to install access valves on
compressors to minimize exposure of the lubricant to the air when charging the system with the new lubricant.
Clearly-marked clean evacuated charging cylinders were then used for transporting the new type of lubricant.
The cylinder was charged with the polyol ester lubricant by weight, and pressurized with a blanket of dry
nitrogen to prevent moisture from seeping in as well as assist flow out of the cylinder once the charging valve
was opened. After charging with the new lubricant, systems were immediately evacuated.
The company also takes other measures to ensure that the systems stay clean and dry during
conversions. Prior to a conversion, systems are flushed thoroughly with the new lubricant and filters are
replaced with types containing materials compatible with the non-CFC refrigerant As a result of these efforts,
the systems become much cleaner inside and require less contaminant-related maintenance. In addition, all
leaks are repaired and the systems are "tuned-up" to engineering specifications to ensure good conversion
success. Following the completion of a conversion, the company's project managers use a very detailed
quality assurance checklist to verify that the refrigeration systems have been installed according to
engineering specifications.
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4.8 Reducing Emissions through Equipment Replacements
When Jitney-Jungle is considering replacing some of its older CFC equipment, leakage rates of the
existing equipment are a prime consideration. If the system has a history of excessive leakage, the company
will replace the system with a state-of-the-art non-CFC system equipped with leak-resistant components. All
components deemed minimally acceptable for use in the field are then evaluated on their potential for leaks
before being specified for installation. For example, the use of a certain pressure-regulating valve was
rejected since it had six more potential leak sites than another valve considered otherwise equivalent in
operation. By considering leakage rates among other factors, the company can recover some of the cost of
retiring the system from reduced costs of maintenance, energy, and refrigerant.
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CHAPTER 5
Emission-Reducing Technologies and Practices
5.1 Introduction
Supermarket facilities personnel have many technical and procedural options to reduce refrigerant
emissions in the construction, modification, service, or repair of refrigeration systems* This chapter gives a
detailed analysis of those options.
Technologies covered in this chapter include new and retrofit system components that can:
prevent damage to system components from accidents, compressor vibration or gas
pulsation;
• resist refrigerant leakage better than standard components;
maintain internal system cleanliness and dryness to reduce maintenance and repair
requirements;
• manage refrigerant charges more effectively, enabling refrigerant charges to be
reduced during regular operations, or isolated and accessed during service
procedures; or
monitor refrigerant concentrations continuously from remote locations.
Operating procedures discussed in this chapter include:
refrigeration system construction procedures to prevent or reduce emissions; and
maintenance and service procedures that cost-effectively reduce emissions.
S.2 Emission-reducing Technologies for New and Retrofit Construction
Refrigerant emissions are best avoided by specifying emissions-reducing options in the design phase.
Most options are best implemented in the initial construction of the systems; others can be cost-effectively
implemented as retrofit measures. ASHRAE Guideline 3 contains good advice on methods to reduce
emissions, and a summary of its contents should be included in the design specifications for all new
supermarket construction. (Reference: ASHRAE, 1990)
The FMI CFC Task Force has stated its position on new equipment; "New installations should be
made with particular attention to piping design and installation of valves and accessories to minimize
refrigerant emissions and permit proper servicing of equipment" In addition, "...any refrigeration system
known to have a history of excessive refrigerant emissions should be replaced with [a new system]."
(Reference: FMI, 1991) Clearly, supermarket engineering leaders have had concerns about the ways in
which new systems are being designed and maintained.
Although all types of emissions of currently viable supermarket refrigerants should be avoided for
global warming reasons, of prime importance is avoiding emissions of ODS. The most effective retrofit
strategy for reducing ODS emissions is simply the application of non-ODS refrigerants in the existing system.
However, this option may require replacement or re-adjustment and fine-tuning of some components, such
as compressors, electrical components, expansion devices, suction riser piping, and lubricant and refrigerant
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charges. The cost to retrofit an average U.S. supermarket of 42,000 square feet* to HFC-based refrigerants
would be approximately $35,000 ($0.83/ff); to retrofit to HCFC-based interim refrigerants would be
approximately $25,000 (50.60/ft2). (Reference: FMI, 1994)
Other less-expensive strategies for reducing emissions of any type of refrigerant can also be
implemented, and these options are discussed below. These options reduce emissions in one of several
manners, including:
• reducing system damage from accidents, vibration or pulsation;
• replacing or substituting for other higher-emitting technologies;
• keeping systems clean and dry and thereby reducing future maintenance
requirements to a certain extent;
effectively managing the refrigerant inside the system to optimize utilization of
refrigerant or to isolate or access refrigerant during service operations; or
monitoring store air for refrigerant on a continuous basis.
5.2.1 Technologies to Control Damage from Accidents, Vibration and Pulsation
Protecting system components from damage due to vibration or accidents is vital to reducing
refrigerant emissions. Frequently, sudden large emissions can be traced back to excessive system vibration
or pulsation. Uncontrolled vibration and pulsation generally cause pipes to flex, abrade, and eventually fail
due to metal fatigue or wear, resulting in accidental releases. Large emissions can also result when pipes
are located in high traffic areas. Even with the best precautions, pipes located in these types of spaces are
likely to eventually suffer concussion, abrasion, or other types of damage and consequently fail. Listed below
are some specific measures designed to minimize damage to system components which would otherwise
result in refrigerant emissions.
Piping Clamps. Certain types of piping clamps greatly reduce the possibility of catastrophic events,
such as broken discharge lines. Clamps should be equipped with vibration-resistant fasteners, such as
locknuts or castle nuts with cotter pins. Clamps should also be equipped with resilient inserts to protect the
piping from the steel clamp. These types of clamps ensure that piping will not come loose during normal
service, thus preventing excessive vibration. This measure is easy and inexpensive to retrofit on existing
systems.
Integral Vibration and Pulsation Eliminating Devices. The decision to use devices to eliminate
compressor vibration and gas pulsation affects both engineers and construction personnel. These devices
include vibration eliminators, baffle plates, and mufflers and are used to control vibration/pulsation in both
suction and discharge lines. Whenever engineers specify the use of these devices, installation personnel
should take care that the devices are securely mounted at the opposite end of the compressor connection,
and are mounted parallel to the compressor shaft, except for baffle plates which are mounted between the
compressor and the discharge service valve. (Reference: FMI, 1991) These technologies can be retrofitted
at moderate cost.
Improved Piping Designs. Both engineering and construction personnel should seek information
on proper piping design. For example, a service bulletin available from a major compressor manufacturer
offers good guidance to system designers and installers. (Reference: Carlyle, 1989) This bulletin discusses
topics critical to vibration-resistant system design such as piping practices to avoid structural resonances,
forced vibration, and acoustical resonances. The bulletin provides in-depth coverage of this topic beyond the
scope of this report,
* 1 square foot = 0.0929 square meter
31
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By becoming familiar with the circumstances under which vibration can damage systems, designers
and installers can identity potential problems with field piping and take action to prevent system damage.
Chronic problems with pre-fabricated systems should be noted and the information relayed back to the
equipment manufacturer. Difficulties with field piping should be discussed with both engineering and
construction personnel. Problems can usually be corrected at moderate cost.
Underground Piping. The practice of locating piping in trenches under the floor slab benefits the
environment and the company by both reducing emissions and saving money. This practice should be
implemented with care. Engineers should emphasize the future serviceability of piping connections in their
designs. They should also consider the possibility of future remodeling that includes modification of the piping
as well as pest control. Retrofits that employ this option are relatively expensive.
5.2.2 Technologies to Replace or Substitute for High-emitting Technologies
Several substitute technologies have been developed to replace older high-emission technologies.
Listed below are some of the more important options to replace or substitute for typically-used components.
All-sweat Expansion Valves and Filters. The use of flared connections on expansion valves and
liquid filter/driers usually results in unnecessary emissions and system downtime. Repeated cycles of thermal
expansion and contraction inevitably lead to flare connections unscrewing. When possible, display cases and
evaporators for walk-in boxes should be installed with sweated expansion valves. Due to the fact that
expansion valves are a frequently-serviced item, incremental costs to retrofit this technology are quite low.
Frost-proof Flare Nuts for Expansion Valves. The condensation that typically forms on
thermostatic expansion valves can turn to ice within the flare nut threads. Since the ice has no path of escape
in typically-designed flare nuts, over repeated cycles, the ice can eventually cause the flare nut to crack.
Frost-proof flare nuts have a unique design that allows the ice a path of escape, ensuring greater system
integrity. In addition, this technology provides an option for those who prefer the flexibility of a flare
connection, but also want lower emissions. Incremental costs associated with this option are low.
Elimination/Avoidance of Hot Gas Defrost. As noted earlier, the hot gas method of defrosting
evaporator coils has the drawback of thermal stress degradation of components. Consequently, other
defrosting methods should be used, (e.g., time-off, electric-resistance or fan-reversal). Retrofits to these
methods, however, are often not cost-effective unless conducted in conjunction with a complete case and/or
cooler box replacement
Low-emission Condensers. Typically-designed condensers occasionally suffer problems with tube
chafing as a result of gas pulsation. In addition, condenser fan mountings can shear off from vibration and
corrosion and puncture the condenser tubing. Emissions associated with condenser leaks can be a very
significant percentage of the total charge, so great care should be taken in selecting features of new
condensers. Condensers designed to minimize bearing stress on tubing bundles have proven effective in
preventing refrigerant emissions. Condensers equipped with large, low-tip-speed fans are also a good
defense against emissions. Retrofits involving this low-emission condensers are usually expensive to
conduct; however, incremental costs may not be that great considering the likelihood of additional emissions
associated with older condensers that have a history of leakage.
Steel capillary tubes. Because copper capillary tubes are subject to large amounts of vibration, they
can easily become damaged and fail if installed or maintained incorrectly, and are cited frequently as the
cause of many fugitive and catastrophic emissions. New compressor racks equipped with pneumatically-
operated pressure controls could be provided with capillary tubing made of steel instead of copper, because
of its better resistance to stress failure, abrasion, and breakage. This technology is very cost-effective to
retrofit. However, these types of capillary tubes still require proper securing and require mechanical
connections.
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Electronic Controls. If possible, capillary tubes should be eliminated altogether, arid should be
replaced by electronic oil and pressure controls. Not only can electronic controls greatly reduce refrigerant
emissions, but they can also act as inputs to a computerized refrigeration controller (RC) or energy
management system (EMS), allowing remote monitoring of system conditions and permitting remote system
troubleshooting. If an RC or EMS is being installed in a new or existing store, serious consideration should
be given to the application of electronic pressure controls to get the best utility out of the system. This option
has low incremental costs to retrofit, given that systems are usually out of operation whenever a capillary tube
has failed, and installation time is not especially long.
Braided steel hose. In applications where suitable electronic substitutes do not exist, braided steel
hose is another viable alternative to copper capillary tubes. This product is compliant and has good vibration-
resistant characteristics. Although the polymer inner hose may be slightly permeable to some refrigerants on
the order of a few ounces per foot per year, it can prevent virtually all catastrophic emissions resulting from
capillary tube failures. Like steel capillary tubing, retrofits to this technology are also cost-effective.
Dual Relief Valves with Rupture Discs. Relief valves are a safety requirement for any type of
system containing liquid under pressure. Dual-relief installation is a particularly effective method, where two
relief valves are connected in parallel with a three-way shut-off valve. This type of configuration allows one
relief valve to be serviced or removed while the system is still being protected by the other relief valve. Each
relief valve should be capable of protecting the system, but only one relief valve should be permitted to shut
off at a time. This configuration can be built-up, or purchased as a single module. When installed in
conjunction with a rupture disk, this configuration can practically eliminate fugitive emissions. Due to the large
amount of labor involved in removing a relief valve, retrofits are usually cost-effective only in the event of a
failure of the old relief valve, or when failure seems imminent due to corrosion.
5.2.3 Technologies to Maintain System Cleanliness and Dryness
It is difficult to estimate the savings that can be attributed to implementing measures to maintain
system cleanliness and dryness due to the diffuse but positive effect this condition has on nearly all system
operations. Nevertheless, a clean and dry system is very desirable. By removing moisture, acids, and
particulates, these measures can significantly reduce the frequency of non-routine servicing.
Oversized Filter/Driers. To compensate for the possibility of errors in construction procedures that
can result in system contamination, oversized in-line replaceable-core filter/driers should be used where
practicable. Since these filters have a large capacity and cross-sectional area, pressure drop is minimized
and the large amounts of contaminants can be handled with ease. Furthermore, since the filter core can be
replaced, systems can be kept in top shape following any procedure that involves breaking the integrity of the
system. This technology entails a moderate cost to retrofit, but when installed with brazed connections, it is
a substantial improvement over small existing filters with flare connections.
Upstream Filters. The use of filters upstream of all expansion devices further reduces system
problems, preventing any particulate matter or ice from clogging the expansion valves. Implementation of this
technology prevents many of the problems that make expansion valves one of the most frequently-serviced
components in a refrigeration system. When one considers the many occasions that system integrity will be
broken over the lifetime of any typical system (e.g., case remodels, component service), the use of upstream
filters can provide inexpensive protection to the system. Given the substantial number of expansion valves
in any given store, retrofits to this technology should be undertaken only when incremental costs can be
minimized, (i.e., when the system is already out of service for another reason.)
5.2.4 Technologies to Effectively Manage Refrigerant
Systems with the capability to manipulate the internal location of the refrigerant often have lower
emissions than other systems. Not only does this capability allow charge sizes to be reduced (an advantage
in the event of an unforeseen catastrophic release), but it also speeds up the process of recovering
refrigerant, thereby minimizing the temptation to some technicians to vent refrigerant to expedite a repair job.
33
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Listed below are some measures that can help to reduce required charge size, or isolate and access
refrigerant during service operations.
Pump-down Capability. System designs that incorporate components to control the location of
refrigerant in the refrigeration system enable mechanics to break system integrity during repairs without having
to remove the entire charge. Pump-down capability requires a receiver large enough to contain the entire
charge of the system. The receiver must also be capable of being isolated through the presence of isolation
valves.
Isolation and Access Valves. Designers should anticipate locations where systems will benefit from
the installation of isolation and access valves, and specify these items to be installed in the proper locations.
Applied system-wide, this small degree of foresight will reap large benefits for the company through reduced
refrigerant recovery time. In many instances, Schrader valves provide the function of access valves. In cases
where Schrader valves are applied, the valves should be connected to the system with brazed connections
and gasketed metal caps should be used. For existing systems lacking access or isolation valves, the
necessary valves should be installed during service operations that require removal of the charge. As part
of an improved leakage prevention program, these types of valves should be checked regularly as they may
leak at the stem.
Charge-reducing Measures. Efforts should also be made to decrease the system refrigerant charge
size to reduce the impact of catastrophic leaks. Several system designs, including remote headers, heat
reclaim pump-out, split condensers, condenser bypass, and loop piping can reduce required charge size.
These measures are not cost-effective in retrofit situations.
Remote headers. Parallel rack charge reduction can be achieved by reducing the
number of pipes coming out of the compressor room. Designers can reduce charge
sizes and piping installation costs by specifying the use of remote headers to collect
and distribute the refrigerant contained in the individual systems' suction and liquid
lines.
Heat reclaim pump-out. To maximize the utilization of the refrigerant contained In
a system, the refrigerant should be pumped out of all components not actively
functioning. The incorporation of a control circuit and components to pump the
refrigerant out of heat reclaim systems after cycle completion is a worthwhile
investment to reduce required charge size.
Split condensers. In the winter months, when systems utilize the most refrigerant
and require the least amount of condenser surface, charge size reduction can be
accomplished by installing the necessary equipment to automatically valve off
sections of the condenser. In this way, pressure can be maintained to feed the
expansion valves adequately, with much less refrigerant required to flood the active
condenser surface.
Condenser bypass. In some parts of the country, ambient winter temperatures are
cold enough for refrigerant to condense entirely back to liquid within the heat
reclamation coil. Components able to sense this condition and valve off the
condenser can be installed to allow systems to operate with even smaller charge
sizes.
» Loop Piping. Like the remote header design, loop piping reduces charge size as well
as the number of connections and joints by extending common pipes from the
compressor racks out into the store area.
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5.2.5 Refrigerant Leakage Monitoring Technologies
Stationary Refrigerant Leak Monitoring Devices. These units typically have alarm capabilities arid
make use of multiple sensors applied at strategic locations throughout the store. Use of these units to detect
leaks and assist in dispatching service personnel to the site can minimize the loss of refrigerant. These units
have the potential to be a valuable complement to a leak detection and repair program that includes regular
system inspections. Whether these units will be a good value for a particular company, however, depends
on the maintenance and service support structure for the stores. These types of units require that sensors
be carefully located to provide the best protection and properly calibrated to minimize false alarms.
Many manufacturers of electronic refrigeration controller systems offer leak monitoring capabilities
at a premium over the price of a regular controller. However, stand-alone refrigerant monitors are also
available on a new or retrofit basis. These devices may be particularly effective if installed in stores known
to have high refrigerant leak rates.
5.2.6 Summary Tables
Tables 5.1 and 5.2 list most of the above emission control options along with industry estimates of
the impact on refrigerant emissions and approximate value of implementing each of the options. (Reference:
Bittner, Burdwood, Mathews, Twisdale) Some options, such as the options to increase system cleanliness
and dryness, were not included because of the difficulty in estimating benefits due to the diffuse effects these
conditions have on system operations,
Each option was assumed to be implemented on two hypothetical typical remote compressor racks:
one three-compressor R-502 low-temperature parallel rack (8 systems) containing a 500 pound charge, and
one single compressor CFC-12 medium-temperature rack containing a 100 pound charge.
A range of incremental capital costs for each option was then calculated based on information
collected from equipment manufacturers. (The incremental capital cost is defined as the difference in cost
between new equipment with the emission control option and industry-standard equipment, including initial
cost, installation and commissioning.) A zero value in the incremental capital cost column indicates that the
option is the same cost or less expensive than the industry standard.
The net present value (NPV) of the option over its lifetime was then calculated based on the following
assumptions:
a 20 year lifetime;
~ an internal value of capital of 7 percent; and
• the option is implemented as a sole emissions reduction measure.
Three different refrigerant prices were used in developing the NPV estimations to show the sensitivity
to increases in refrigerant price. In addition, to show the sensitivity to higher levels of baseline refrigerant
emissions, a multiplier of 3.0 was applied to the expected reduction in emissions to generate a range of NPVs
at each refrigerant price point. To maintain conservative values, calculated NPVs do not include the value
of business lost for equipment downtime due to loss of refrigerant charge, decreased required maintenance,
or avoided labor to recharge refrigerant following a leak event.
The simple formula shown below was used to generate the values in the following tables:
NPV = PV(ERE x RP) - EC
where:
NPV is the net present value of the option;
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PV is the present value of the cash flow from reduced emissions;
ERE is the expected reduction in emissions in pounds per year;
RP is the refrigerant price; and
EC is the cost of the option.
5.3 Emissions-reducing Operating Practices
The practices involved in constructing, maintaining, servicing, and retiring refrigeration systems have
a significant bearing on the amount of refrigerant consumed by the system in the long-term. Emissions-
reducing procedures involving construction personnel include:
• use of proper brazing practices;
use of proper pipe securing practices;
• use of proper construction quality assurance practices; and
use of portable leak detectors.
Tables 5.3 and 5.4 list some of these emission-reducing control options for construction, service and
maintenance personnel along with industry estimates of the cost (including labor), impact on refrigerant
emissions, and approximate value of implementing each of the options. As in the previous section, two
hypothetical typical remote compressor racks were assumed to incorporate each of the measures in isolation.
In addition, all assumptions are consistent with the previous tables. It is important to note that several of the
control options would be shared among several independent refrigeration systems in each store {or many
stores, in the case of portable leak detectors); therefore, the costs are assumed also to be shared.
5.3.1 Construction Practices
Construction practices can significantly affect the emissions levels from refrigeration equipment The
success of engineering system design improvements that reduce emissions depends heavily on the care
taken during system construction. Discussed below are some practices that can be cost-effectively
implemented in the construction of refrigeration systems to reduce emissions.
Brazing practices. Proper methods of joining components together can greatly enhance the leak
resistance of joints as well as protect the entire refrigeration system. To reduce the required number of
connections, piping runs should be as direct as possible, and full lengths of pipe should be used when
feasible. To eliminate the formation of oxides during brazing operations, a cylinder of nitrogen or other inert
gas should be attached to the section being brazed, and the valve cracked open slightly to allow a small
quantity of the protective gas to flow through the section and displace any air. To increase the strength of the
connections, solder of sufficient silver content should be used to ensure strong, leak-resistant connections.
For most applications, solder containing at least 15 percent silver is appropriate.
Pipe securing practices. The method used to secure piping is critical to preventing emissions,
especially the large emissions associated with broken discharge lines. Technical bulletins dealing with such
problems are available through some equipment manufacturers8 The use of piping clamps is usually the
easiest and most effective way to correct vibration problems. In general, piping must be clamped to a
structure that has sufficient stiffness to be effective, or else vibration resonance problems may occur, causing
8 Various companies, including Carlyle, Copeland, Hussmann, and Trane, have produced technical
bulletins that discusses vibration problems with piping.
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TABLE 5.1
COSTS AND BENEFITS OF LEAK REDUCTION TECHNOLOGIES -
PARALLEL THREE-COMPRESSOR LOW-TEMPERATURE R-502 RACK (8 SYSTEMS),
500 POUND CHARGE
Option
Typical
Range of
Incremental
Capital Cost
(Dollars)
Expected*
Reduction
in
Emissions
<% of
charge per
year)
Range of Lifetime Net Present Values of
Implementing Option (Dollars)
$7.50/lb
$15/lb
$22.50/lb
Clamps with castle or lock nuts
0
5
27
54
80
Discharge mufflers
25-65
5
-38 to 2
-11 to 29
15 to 55
Baffle plates
15-30
5
-3 to 12
24 to 39
50 to 65
Vibration eliminators
5-45
5
-18 to 22
9 to 49
35 to 75
Proper piping design
0
6
33 to 96
66 to 193
100 to 289
Underground piping
0
4
24 to 71
47 to 141
71 to 212
All-sweat TXVs and filters
0
5
29 to 87
58 to 174
87 to 260
Frost-proof flare nuts for
expansion valves
0
5
27 to 80
54 to 161
80 to 241
Avoidance of Hot Gas Defrost
0
8
44 to 132
88 to 264
132 to 395
Low emission condensers
0-150
g
-104 to 138
-58 to 276
-12 to 415
Steel cap tubes
30-40
3
-25 to 15
-10 to 60
5 to 105
Braided steel hose
35-40
3
-25 to 10
-10 to 55
5 to 100
Electronic controls
0
3
15 to 45
30 to 90
45 to 135
Dual-relief valves
80-100
5
-73 to-53
-46 to -26
-20 to 0
Remote headers
0
4
24 to 71
47 to 141
71 to 212
Loop piping
0
4
24 to 71
47 to 141
71 to 212
Heat reclaim pumpout
120-170
5
-143 to -93
-116 to-66
-90 to -40
Split condensers
250-350
5
-323 to -223
-296 to -196
-270 to-170
Condenser bypass
300-500
5
-473 to -273
-446 to -246
-420 to -220
Stationary leak monitors
150-275
25
-141 to-16
-7 to 118
127 to 252
* In interpreting the values for the expected reduction in emissions, a certain degree of caution must be used:
the values are independent estimates for each option implemented in isolation; implementing several options
would not give reductions equal to the summation of the individual reductions because many options are co-
dependent with other options.
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TABLE 5.2
COSTS AND BENEFITS OF LEAK REDUCTION TECHNOLOGIES -
SINGLE-COMPRESSOR MEDIUM-TEMPERATURE R-12 RACK, 100 POUND CHARGE
Option
Typical
Range of
Incremental
Capital Cost
(Dollars)
Expected*
Reduction
in
Emissions
<% of
charge per
year)
Range of Lifetime Net Present Values of
implementing Option (Dollars)
$7.50/lb
$15/lb
S22.50/lb
Clamps with castle or lock nuts
0
5
5
11
16
Discharge mufflers
25-65
5
-60 to 20
-54 to -14
-49 to -9
Baffle plates
15-30
5
-25 to-10
-19 to -4
-14 to 1
Vibration eliminators
5-45
5
-40 to 0
-34 to 6
-29 to 11
Proper piping design
0
5
5 to 16
11 to 32
16 to 48
Underground piping
0
3
3 to 11
6 to 21
10 to 32
All-sweat TXVs and filters
0
4
4 to 13
9 to 26
13 to 39
Frost-proof flare nuts for
expansion valves
0
4
4 to 13
9 to 26
13 to 39
Avoidance of Hot Gas Defrost
0
5
5 to 16
11 to 32
16 to 48
Low emission condensers
0-150
22
-126 to 71
-103 to 141
-79 to 212
Steel cap tubes
30-40
14
-25 to 15
-10 to 60
5 to 105
Braided steel hose
35-40
14
-25 to 10
-10 to 55
5 to 100
Electronic controls
0
14
15 to 45
30 to 90
45 to 135
Dual-relief valves
80-80
5
-75 to -55
-69 to -49
-64 to -44
Stationary leak monitors
50-90
25
-63 to -23
-36 to 4
-10 to 30
* In interpreting the values for the expected reduction in emissions, a certain degree of caution must be used:
the values are independent estimates for each option implemented in isolation; implementing several options
would not give reductions equal to the summation of the individual reductions because many options are co-
dependent with other options.
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TABLE 5.3
COSTS AND BENEFITS OF OTHER LEAK REDUCING OPTIONS -
PARALLEL THREE-COMPRESSOR LOW-TEMPERATURE R-502 RACK, 500 POUND CHARGE
Option
Typical
Range of
Incremental
Capital Cost
(Dollars)
Expected*
Reduction in
Emissions
(% of charge
per year)
Range of Lifetime Net Present Values
of Implementing Option (Dollars)
$7.50/lb
$15/lb
$22,50/lb
Use of Portable Leak Detectors
2-4
16
82 to 189
167 to 341
253 to 512
Use of 15 percent solder
0-20
5
7 to 27
34 to 54
60 to 80
Use of refrigerant accounting system
10-20
16
66 to 161
151 to 333
237 to 504
Improved preventive maintenance
0-200
40
14 to 268
229 to 536
443 to 804
Fixed-price maintenance contracts
0
16
86 to 171
171 to 343
257 to 514
* In Interpreting the values for the expected reduction in emissions, a certain degree of caution must be used:
the values are independent estimates for each option implemented in isolation; implementing several options
would not give reductions equal to the summation of the individual reductions because many options are co-
dependent with other options.
TABLE 5.4
COSTS AND BENEFITS OF OTHER LEAK REDUCING OPTIONS -
SINGLE-COMPRESSOR MEDIUM-TEMPERATURE R-12 RACK, 100 POUND CHARGE
Option
Typical
Range of
Incremental
Capital Cost
(Dollars)
Expected*
Reduction in
Emissions
(% of charge
per year)
Range of Lifetime Net Present Values
of Implementing Option (Dollars)
$7.50/lb
$15/lb
$22.50/lb
Use of Portable Leak Detectors
1-2
16
82 to 169
167 to 341
253 to 512
Use of 15 percent solder
0-20
5
7 to 27
34 to 54
60 to 80
Use of refrigerant accounting system
10-20
16
66 to 161
151 to 333
237 to 504
Improved preventive maintenance
0-70
40
14 to 268
229 to 536
443 to 804
Fixed-price maintenance contracts
0
16
86 to 171
171 to 343
257 to 514
* In interpreting the values for the expected reduction in emissions, a certain degree of caution must be used;
the values are independent estimates for each option implemented in isolation; implementing several options
would not give reductions equal to the summation of the individual reductions because many options are co-
dependent with other options.
39
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noise and transmitting vibration to other refrigeration system or building elements. Clamps should be oriented
to constrain the maximum motion of the piping, (e.g., if the direction of maximum motion is vertical but the
piping is clamped horizontally, the clamp will be less effective, and may even exacerbate the problem).
Improper constraint may induce excessive stress that can increase the likelihood of piping breakage.
Quality assurance practices. Prior to placing any refrigeration system into service, the systems
should be rigorously pressure tested first to ensure system integrity. A preliminary rough leak test should
consist of pressurizing the system to one-half of operating pressure with dry nitrogen and then using a soap-
and-water solution to produce bubbles at leak sites. Safety controls and relief valves first should be removed
and their orifices plugged before conducting the test. Once it is determined that gross leakage has been
eliminated, a more thorough evaluation can be conducted by fully pressurizing the system and applying the
soap-and-water solution again. A final pressure test would entail using a mixture of dry nitrogen and a small
quantity of the HFC refrigerant intended for use. Portable electronic leak detectors can then be used to locate
any remaining leaks.
Once all leaks are eliminated, the system should then be subjected to a standing vacuum test. This
test involves multiple evacuations down to progressively lower vacuum levels to remove moisture and non-
condensible gases, breaking the vacuum each time with dry nitrogen. Removal of all water vapor is crucial
to successfully applying HFC refrigerants and the polyol ester lubricants used with them, due to their high
affinity for water. Upon the third evacuation, the system should be allowed to stand for 12 hours and the
pressure monitored to verify system integrity.
Following this test, the system can be recharged with nitrogen slightly over atmospheric pressure and
the driers, safety controls, and relief valves installed. After completion of component installation, the system
should be evacuated once more and then charged with refrigerant.
5.3.2 Repair Service and Preventive Maintenance
Both repair service and preventive maintenance are critical elements in a program to minimize
emissions from refrigeration systems. Personnel working in these areas should not underestimate the impact
their practices can have on reducing operating costs and protecting the environment
System Servicing
For equipment containing more than 50 pounds of refrigerant, EPA regulations limit total leakage to
35 percent of total charge per year. This accounts for the majority of equipment installed in U.S.
supermarkets. Leakage can be reduced in a cost-effective manner through a carefully constructed strategy
for system service and repair. As a result, the practice of regular and thorough leak inspection and repair not
only helps comply with the law, but also provides the best value to the supermarket.
Like the recommendations made for design personnel in section 5.2, service technicians can improve
their practices by following recommendations made in ASHRAE Guideline 3. (Reference: ASHRAE, 1990)
These recommendations are briefly listed below.
• Only properly trained personnel should engage in system servicing or refrigerant
handling.
• Per the provisions of the Clean Air Act, ODS refrigerants are not to be vented to the
atmosphere for any purpose other than for accepted service practices that result in
de minimis emissions (e.g., attaching service gauge hoses).
• Causes of refrigerant emissions should be found and remedied prior to recharging
any system. Following leak repair, systems should be retested to verify repair
integrity. Systems should be replaced if losses continue even after applying good
maintenance practices.
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* Periodic testing of both refrigerant and oil for contaminants is critical to assessing
system health and avoiding service events.
Compressor oil should be degassed prior to removing it from the compressor to
reduce the concentration of dissolved refrigerant
* Refrigeration systems that have suffered a motor burnout may be contaminated with
carbon or sludge. The oil should be examined to determine the extent of the
contamination. In the event of a severe burnout, ODS refrigerant must be
transferred to an business that performs refrigerant reclamation or disposal.
Preventive Maintenance
Companies can reduce their overall maintenance costs while protecting the environment through the
implementation of practices that reduce emissions as part of an overall preventive maintenance program.
Other goals that can be attained from this type of preventive maintenance program include:
reduced unscheduled maintenance in general;
reduced replacement refrigerant costs; and
* better and more efficient system performance.
Preventive maintenance programs geared towards reducing emissions would benefit from including
the following items:
a system charging and maintenance log;
regular walk-through system inspections;
regular major system inspections;
impromptu inspections; and
reassessment of existing maintenance agreements with external contractors.
System charging and maintenance log. Diligently maintaining a log of refrigerant and oil transfers
and repair procedures is essential to assess the integrity of the refrigeration systems as well as to track the
movement of refrigerant throughout the company. This log should be kept on an individual equipment basis
and include the operating charge as well as all additional recharges. The log should also indicate both regular
and unscheduled service and all items inspected or repaired. Companies should consider making it a
requirement for contractors or in-house maintenance personnel to provide a periodic refrigerant replacement
report that summarizes the activities in each store.
Alternatively, companies can purchase software to track the refrigerant. Computer programs exist
that not only track refrigerant movement, but also monitor equipment service events to identify problem
systems. Some programs can also interface directly with certain accounting programs and save on labor to
track refrigerant.
Regularly scheduled walk-through inspections. Maintaining control over refrigerant expenses is
extremely difficult without regular leak detection and repair. A system inspection schedule for all stores should
be established, setting aside a minimum number of hours each week or month for inspection and repair
activities. In addition, the schedule should include both major and minor inspections. Companies that already
conduct regularly scheduled inspections should weigh the costs and benefits of increasing the frequency and
rigor of these inspections.
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Walk-through inspections should include (at a minimum) a visual inspection for refrigerant leaks in
both the compressor room and the sales area. Portable battery-operated electronic leak detectors provide
additional protection against refrigerant emissions if visual inspections fail to indicate remaining leaks. In
addition, factors that could result in future leaks should be identified, such as loose connections, pipe or
capillary tube chafing, or excessive vibration within the high-temperature, high-vibration parts of the
equipment.
Flanged and flared connections should receive particular attention at the time of the inspection. Valve
packings and service valve caps should be inspected and tightened if loose. Brazed connections should also
receive some attention, if time permits. In addition, system "vital signs" should be monitored during a walk-
through inspection. These "vital signs" include oil levels, pressures and temperatures, refrigerant levels, and
compressor suction and discharge pressures.
Major Inspections. At least once a year, the refrigeration systems in each store should undergo a
major inspection. In addition to those activities conducted during walk-through inspections, the system should
be shut down temporarily to carefully inspect the condition of all components in the system and the coil
surfaces should be cleaned. Cleaning coil surfaces not only helps to maintain system efficiency through
improving heat transfer but also reduces system pressure, decreasing the potential for leaks. After the system
is put back into operation, vital signs (pressures and temperatures) should be noted and entered into the log
as a basis for comparison.
Impromptu Inspections. If technicians have sufficient time between assignments, they should be
encouraged to conduct an impromptu walk-through inspection of the refrigeration systems. These types of
inspections have the lowest cost of any type of preventive maintenance measure and can possibly result in
the prevention of significant refrigerant emissions.
Outside contractors. As pari of an overall review of the maintenance program, contracts with
contractors should also be reviewed. If the review indicates that the contractor does not have proper incentive
to find and repair refrigerant leaks, the contract should be revised and renegotiated. Compensation for
contractors should become contingent on the contractor providing periodic refrigerant replacement reports.
Having a list of preferred contractors who have been trained in company procedures is of great benefit
to an emissions reduction program. Educating contractors should be considered essential to keeping the
actions of the contractor consistent with the mission of the supermarket. Educational curricula should include
formal instruction on procedures and schedules for service items (e.g., refrigeration system oil changes and
refrigerant leak detection and repair).
5.4 Analysis of Data on Refrigerant Emissions
In order to estimate the impact of various emission controls, experts in supermarket engineering and
maintenance were contacted and asked to provide any data collected in this area. (Reference: Bittner,
Burdwood, Mathews, Twisdale) To support the experts' judgments, ICF conducted research in the area of
refrigerant leakage from typical systems to estimate independently the impact of implementing emissions-
reducing measures on these systems.
In two previous reports, researchers had been largely unsuccessful in obtaining measured data on
emissions from supermarkets. (Reference: Harrison et al., 1995; Rand, 1979) Research conducted for this
report confirms the scarcity of available data in this area; however, two sources of recorded data were located.
The first source of formal data was a midwestern supermarket chain that provided refrigerant
recharging reports. The second source was the South Coast Air Quality Management District (SCAQMD),
which provided system recharging auditing records from several retail food companies falling within its
jurisdiction.
Emissions reductions ideally would have been estimated from a large population that included a
variety of companies, stores, configurations of refrigeration units, leakage rates, service practices, and
42
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contractor/in-house maintenance and engineering support arrangements. Analysis of such a population would
have been more statistically rigorous than the present analysis. However, these kinds of data were not
volunteered and may not exist.
5,4.1 Midwestern Chain Recharging Reports
One midwestern chain volunteered data on all of its refrigeration equipment. These data were
collected for the entire chain over a period of one year and were aggregated at the sub-system level. The data
were provided already in summarized form, and only a slight analysis was required. Some background
information on the chain is listed below.
It operates 110 stores averaging 34,000 square feet each.
Refrigeration for each store is mainly provided by two or three large parallel
compressor racks. The chain maintains approximately 300 of these racks.
Each rack averages 65 horsepower* and services approximately 15 systems.
* The grand total refrigerant charge contained in all of its stores is approximately
270,000 pounds.
The chain's remote refrigeration equipment required recharging 287 times in 1992.
The annual leakage rate for the chain is relatively low - 15 percent of total charge
in 1992.
The chain maintains this low emissions rate by requiring that several procedures be followed by its
contractors.
All equipment must be installed per the chain's written specifications.
* All equipment must be able to maintain a 500 micron (67 Pa) vacuum for 24 hours
before charging is permitted.
Refrigerant loss reports must be filled out for contractors to receive reimbursement
for services rendered.
* Receiver inspections are conducted routinely.
Systems installed in last three years use all-sweat expansion valves. To date, none
of these valves have experienced any leakage.
Data provided on a subsystem basis for the chain's remote equipment included the total amount of
refrigerant released and the number of service calls for recharging refrigerant. From these data, the average
amount released per service call was calculated. An analysis of the data reveals several interesting
phenomena. The analysis showed a high correlation between the total amount of refrigerant released and
the number of service calls for recharging refrigerant. However, the release amount per service call showed
little correlation with the average release per service call, suggesting that, in general, large releases had only
a small impact on total refrigerant recharges.
* 1 Horsepower = 0.746 kW
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Of the 18 subsystems, two in particular dominated total refrigerant releases, accounting for over one-
third of all emissions: the condenser and hot gas defrost subsystems. This observation is not particularly
surprising, given the severe conditions under which these two particular subsystems must operate. Ranking
third on the list, thermostatic expansion valves (TXVs) accounted for another 10 percent of total releases.
Releases from TXVs are generally considered to be substantial for many companies in the industry, and the
company providing these data is no exception.
These three subsystems also ranked at the top for number of service calls involving recharging,
suggesting that for these subsystems, regular inspections to minimize number of service calls would be
particularly useful in minimizing refrigerant loss. The condenser and hot gas defrost subsystems also had
high average emissions per service call (ranking in the top half of all subsystems), indicating that for these
two subsystems, design improvements targeted at reducing large emissions could also have an impact on
overall emissions.
Liquid line solenoid valves, service valves and stem packings, and pressure controls ranked fourth
through sixth for total refrigerant releases. These same three subsystems also ranked among the top six for
number of service calls involving recharging, but had average to low rankings for average release amounts
per service call. This observation suggests that increasing the number of preventive maintenance leak
inspections to reduce the number of service calls would be the action most likely to minimize total releases
for these subsystems.
The subsystems ranked at the very top for average refrigerant releases per service call were, in order,
receiver relief valves, discharge header tubing, suction line tubing, liquid line tubing, and evaporator coils.
However, all of these subsystems were ranked in the lower half for total amount of refrigerant released,
reinforcing the previous assertion that large releases have only a small impact on this chain's total refrigerant
consumption.
These observations suggest that this chain can reduce refrigerant consumption most effectively by
focusing on subsystems that are most frequently serviced, and not on subsystems that have the highest
average emissions per service call. Table 5.5 summarizes the company's recharging experiences at the
subsystem level.
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TABLE 5.5
REFRIGERATION SUB-SYSTEM RELEASES AT A MIDWESTERN SUPERMARKET CHAIN
Subsystem
Total
Amount of
Refrigeran
t Released
(lbs)
Percentage
of Total
Emissions
and (Rank)
Number of
Service
Calls for
Recharging
Refrigerant
Percentage
of Total
Number of
Calls and
(Rank)
Release
Amount per
Service Call
(lbs) and
(Rank)
Condenser1
6,410
17 (1)
47
16 (1)
137 (9)
Hot gas defrost2
6,163
17 (2)
44
15 (2)
140 (8)
Expansion valves
3,879
10 (3)
35
12 (3)
111 (14)
Liquid iine solenoid valves
2,494
7 (4)
22
8 (5)
113 (12)
Service valves, stem packings
2,285
6 (5)
27
9 (4)
85 (18)
Pressure controls3
2,120
6 (6)
19
7 (6)
112 (13)
Not properly charged4
1,930
5 (7)
13
5 (9)
148 (6)
Suction line tubing®
1,875
5 (8)
9
3 (11)
208 (3)
Liquid line tubing6
1,555
4 (9)
8
3 (13)
194 (4)
Evaporator coils
1,470
4 (10)
8
3 (12)
183 (5)
Discharge header tubing
1,327
4 (11)
5
2 (14)
265 (2)
Compressor fittings, oil lines
1,265
3 (12)
14
5 (7)
90 (16)
Heat reclaim7
1,240
3 (13)
14
5 (8)
89 (17)
Receiver relief valves
1,110
3 (14)
4
1 (15)
278 (1)
Sight glasses
1,084
3 (15)
9
3 (10)
120 (11)
Demand cooling valves8
430
1 (16)
3
1 (17)
143 (7)
Braided hoses
367
1 (17)
3
1 (16)
122 (10)
Filters and driers
227
1 (18)
3
1 (18)
92 (15)
11ncludes circuit-splitting piping, solenoid valves, check valves, 3-way valves, flooding valves, fen controls,
and condenser tubing.
2 Includes check valves at evaporator, EPR valves, hot gas solenoid valves, and liquid line differential valves.
3 Includes capillary tubes and flare connections on pneumatic controls.
4 Includes improper winter charging and miscellaneous leakage where no significant leaks were found.
5 Includes suction lines from evaporators to suction header.
6 Includes liquid lines from liquid header to evaporators. Note that in one event a single underground liquid
line released 450 pounds.
7 Includes check valves, 3-way valves, heat reclaim tubing.
8 For HCFC-22 applications only.
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5.4.2 South Coast Air Quality Management District Audit Reports
The South Coast Air Quality Management District (SCAQMD) is a California government agency
responsible for regulating air pollution in Southern California. In 1991, the agency issued a regulation, Rule
1415, that provides for the monitoring of commercial refrigeration systems. As a result of the requirements
of Rule 1415, retail food companies operating in the jurisdiction of the SCAQMD are required to record:
* the amount of and reason for refrigerant being charged into any refrigeration system,
and
~ the annual refrigerant leakage status of each refrigeration system on the premises,
including non-leaking systems.
Refrigeration system audit reports already part of the public record were provided by SCAQMD for
this analysis. A total of 440 recharging and leak testing events were included in the reports from 56 different
stores representing 20 different businesses. A statistical analysis of the data provided in the records indicates
that refrigerant emissions from commercial refrigeration systems in the SCAQMD jurisdiction were
approximately eight percent of total charge in 1993.
Methodology
A general statistical characterization of leak events could inform supermarkets on whether to focus
their emission-reduction resources on improving maintenance practices (more effective in preventing fugitive
emissions) or improving system designs (more effective in preventing catastrophic emissions). An earlier
survey on emissions from retail food stores concluded that refrigerant consumption results almost exclusively
from catastrophic releases. (Reference: Harrison et a!., 1995) The analysis conducted for this report
attempted to test the findings of the earlier survey.
Supermarket systems are generally recharged upon inspection or when the remaining charge falls
below a critical level (approximately 20-40 percent of total charge for parallel-compressor racks and 40-70
percent for single-compressor racks, depending on individual system characteristics). As a result, one would
expect to find a pattern in the percentages of refrigerant recharge required upon discovery. In this analysis,
for each documented recharging event, the total amount of refrigerant recharged was divided by the total
system charge. The resulting fraction was called the recharging percentage. These recharging percentages
were then separated into decile categories (i.e., 0-9%, 10-19%,...) and the populations within each decile
category were then analyzed separately from the larger population.
If parallel-compressor-type equipment predominated and recharging amounts fell primarily within the
first four deciles, one might suspect that leaks could be primarily classified as fugitive, at least in frequency.
This supposition was validated in the ICF study.
An attempt was made to reconcile the findings with actual field practices. Recharging events falling
within the first two deciles could be explained by fugitive emissions that were caught in the early stages by
regular or chance inspections. Recharging events falling within the third and fourth deciles would likely
indicate that sources of fugitive emissions were not found until system performance of parallel racks was
impaired from insufficient refrigerant. Recharges within the next three deciles (40 to 70 percent) could be
explained by declining system performance of single-compressor racks. Recharges of 100 percent almost
certainly would be the result of a catastrophic leak. Table 5.6 details some findings from the statistical
analysis.
The preponderance of recharging events involved refrigerant amounts less than 40 percent of total
system charge. A smaller number of events involved refrigerant amounts from 40 to 67 percent of total
system charge. A very small amount of events involved total system recharges. One interesting finding was
that no events involved recharging amounts from 67 to 99 percent of total system charge; however this finding
may have more to do with the small population size than leakage characteristics of refrigeration systems in
general.
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Further analysis suggested that not only do fugitive emissions occur more often than catastrophic
emissions, but they also account for more aggregate refrigerant loss. Total recharges occurred in only 2
percent of recharging events, and accounted for only 8 percent of total refrigerant consumption. One would
expect to find a preponderance of total charge releases and resulting recharging events if the conclusion of
the previous survey was correct - that emissions result almost exclusively from catastrophic releases.
(Reference: Harrison et a!., 1995) The results of the analysis conducted for this report, however, contradict
the conclusion of the earlier survey.
Further, the analysis suggests that most leaks reported by auditors were high-side leaks; few occurred
on the low-side. Leaks involving the condenser almost invariably resulted in major, if not total charge loss.
A final analysis of the data revealed that, other than from condensers, leakage rates from any other
component may range from a very small percentage of the charge to the entire charge.
Caveats
Several circumstances surrounding the data provided should be considered in attempting to
extrapolate the findings to supermarket refrigeration equipment in general.
~ Industry-wide data were not available to perform a comprehensive statistical
analysis.
The population analyzed was small.
The nature of the maintenance practices in the SCAQMD jurisdiction other than leak
repair was not reported in the audits.
The accuracy and completeness of the data reported under the auditing
requirements is unknown.
The figure calculated for the leak rate of the population is not unachievable, but is
quite low compared to the rest of the industry; however, the figure could indicate that
emission-reducing measures are already being implemented in the SCAQMD
jurisdiction.
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TABLE 5.6
STATISTICAL ANALYSIS OF SCAQMD AUDIT REPORTS
Item
Percentage recharged
None
1-9
10-19
20-29
30-39
40-49
50-59
60-69
70-79
80-89
90-99
100
Number of
Events9
287
68
16
17
16
7
14
5
0
0
0
10
Most Frequent
Leak Sources
TX
PL
CT
SH
DS
BR
EV
HR
CT
VP
FD
FT
RE
SS
PL
CT
FT
TX
HR
TX
FT
CO
PH
CO
FT
HR
BR
PH
FT
CT
BR
PH
CO
DS
HR
GH
Aggregate
Number
287
117
26
10
Percentage of
total
population
65
27
6
2
BR
Brazed Connection
FT
Flare, TXV
SH
Schrader Valve
CO
Condenser Piping
GH
Gasket, High-Side
SS
Suction Service Valve
CT
Capillary Tube
HR
Heat Reclaim Piping or Valve
TX
TXV, problem unspecified
DS
Discharge Service Valve
PH
Piping, High-Side
VP
Valve Packing
EV
Evaporator Piping
PL
Piping, Low-Side
FD
Flare, Drier
RE
Relief Valve
9 An event is defined as either a recharge or an audit indicating no leaks.
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CHAPTER 5 REFERENCES
1. The American Society of Heating, Refrigerating and Air-conditioning Engineers. Guideline 3 -
Reducing Emissions of Fully Halogenated CFC Refrigerants in Refrigeration and Air-conditioning
Equipment and Applications. 1990.
2. Food Marketing Institute. Guidelines for the Phaseout of Chlorofluorocarbons In the Retail Food
Industry. April 1991.
3. Food Marketing Institute. Guidelines for the Use of Alternative Refrigerants in the Supermarket. May
1994.
4. Carlyle Company. OEM bulletin 118 - Recommendations to minimize refrigerant line vibration.
February 1989.
5. Robert E. Bittner, II, P.E., Giant Food. Personal Communication. March 1994.
6. William Burdwood, Shaw's. Personal Communication. March 1994.
7. Tom Mathews, Hannaford Brothers. Personal Communication. April 1994.
8. Norman Twisdale, Jitney-Jungle. Personal Communication. July 1994.
9. M. R. Harrison, R. C. Keeney, T. P. Nelson. Pilot Survey of Refrigerant Use and Emissions from
Retail Food Stores. ASHRAE Transactions, Vol. 101, Pt. 1, 1995.
10. Rand Corporation. Domestic Use and Emissions of Chlorofluorocarbons in Retail Food Store
Refrigeration Systems. April 1979.
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