COMMERCIAL REFRIGERATION SYSTEMS EMISSIONS

Donald B. Bivens DuPont Fluoroproducts

210 West Locust Lane Kennett Square, PA 19348

Phone: 610-444-9140

Fax: 610-444-9659 Donald.b.bivens-1@usa.dupont.com

Cynthia L. Gage US Environmental Protection Agency Office of Research and Development Research Triangle Park, NC

ABSTRACT Commercial refrigeration systems refrigerant emissions in the 1980’s were reported to be in the range of 20-35% of refrigerant charge on an annual basis for developed countries. The high

emission rates were due to desi gn, construction, installation, and service procedures followed without awareness of potential environmental impa ct. Emissions have been decreasing due to industry actions and governmental regulations for refrigerant containment, recovery, and usage record keeping, increased personnel training, im proved service procedures, and attention to many details in system design. This paper will pr ovide a progress report on refrigerant emission reductions from commercial refrigeration systems, estimates for future emissions, plus life cycle climate performance calculations for several refrigeration system options.

INTRODUCTION Commercial refrigeration systems have many differences in terms of size and applications.

Stand-alone equipment consists of systems where a ll the components are integrated, such as beverage vending machines, ice cream freezers, and stand-alone display cases. The systems are hermetic with small refrigerant charge sizes (0.2 – 1 kg), and have low refrigerant emissions at

≤ 1% of charge annual loss /Mar98; ADL02/.

Condensing units are small commercial systems with compressors and condensers located external to the sales area, and the evaporators in display cases in the sales area, or in a cold room for cold storage. These units ar e installed in shops such as ba keries, butchers, and convenience stores in non-Article 5(1) countries, and in larger food retailer stores in Article 5(1) countries. These systems have larger charge sizes (1-5 kg) , and refrigerant emissi ons depend on robustness of system design, installation practices, and maintenance procedures. Refrigerant emissions are estimated in the range of 1-10% of charge annua l loss, with the average likely toward the upper portion of the range /Mar98; AEA03/.

Centralized systems consist of a series of compressors and condensers located in a remote machinery room, providing a cooling medium to disp lay cabinets and cold storage rooms in other parts of the building. The size of systems can vary from cooling capacities of 20 kW to more than 1 MW, as used in larger supermarkets. Refrige rant charge sizes can range from 100 to 2,000 kg. The most common form of centralized system is termed direct expansion (DX), in whichrefrigerant circulates throughout the system. Specifi c units can be dedicated to low, medium, or high temperature evaporators.

The centralized systems as just described had refrigerant emissions in the 1980’s reported in the range of 20-35% of charge on an annual basis /Fis91; AEA03; Ped03/. The high emission rates were due to design, construction, installation, and service practices followed without awareness of potential environmental impact. Emissions from these systems have been decreasing due to industry actions and governmental regulations for refrigerant containment, recovery, and usage record keeping, increased personnel training, im proved service procedures, and attention to many details in system design, construction, and installation.

A variation of the DX centralized system is the indirect expansion system (also termed secondary loop system) in which the centralized refrigeration system cools a heat transfer fluid which is circulated to the display cases and cold storage ro oms. This design permits a refrigerant charge size reduction of 75-85%. Fluorocarbon-based refrige rants are used in these systems, and if the centralized refrigeration system can be located in a controlled-access room away from the customer sales area, indirect systems may also use flammable and/or toxic refrigerants, depending on system safety measures and country safety regul ations. Refrigerant emissions are reduced to 2- 4 % of charge per year /ADL02/ due to redu ced refrigerant piping lengths and number of connecting joints.

Another variation of the DX supe rmarket refrigeration system is the distributed system in which compressors are located in sound-proof boxes near the display cases, permitting the shortening of refrigerant circuit lengths and re duction of refrigerant charge by 75%. Condensing units can be air-cooled or water-cooled. With the close-coupled system design, average refrigerant emissions are estimated at 4% of charge on an annual basi s /ADL02/. The reduced refrigerant charge size and emission rates result in significantly lower cli mate change impact for the distributed system versus the centralized DX system.

Finally, a third version of the DX centralized system is a cascade system with HFC refrigerant in the medium temperature stage, and carbon dioxid e as refrigerant in the low temperature stage. These systems have been tested in Europe sin ce 2000, with good experience in terms of cost and energy efficiency /Haa02/.

Centralized supermarket refrigeration systems are the main focus of this paper, as refrigerant emissions from commercial refrigeration systems were estimated to be 24% of worldwide refrigerant emissions in the year 2000 /Pal03/, and the centralized systems have the higher leakage rates in the commercial refrigeration sect or. Energy efficiency is also an important consideration, as total climate change impact of a system is the combination of refrigerant emissions plus carbon dioxide emissions from fossil fuel power plants to generate the power to operate the refrigeration system. These two factor s are combined to quantify the climate change impact of a refrigeration system, and example cal culations will be provided in this paper.

REFRIGERANT EMISSIONS

As reported in the INTRODUCTION, centralized DX supermarket systems had high rates of refrigerant emissions in the 1980s. Studies and implementation of measures to reduce emissions from these systems will be describ ed following. In addition, info rmation on country initiatives for refrigerant conservation (emi ssion reduction) are described in the 2002 UNEP TOC report,

sections 4.7 and 10.1-10.9 /UNE02/.The Netherlands In the Netherlands, emissions have been si gnificantly reduced through national mandatory regulations established in 1992 for CFCs, HCFCs, and HFCs, assisted by an industry initiated certification model (STEK). The Dutch regulations consist of several elements /Ger98/, with the following listed as examples:

• New systems and modifications of existing systems must fulfill detailed technical requirements to improve tightness.

• Flared joints are forbidden.

• Overpressure protection designed such that refrigerant emission to the ambient is minimized.

• System commissioning procedures include pressure and leakage tests.

• Each system has a log book for recording system failures, refrigerant additions, maintenance activities, and leak detection test results.

• Periodic system inspections conducted, includi ng leak tightness. Systems with refrigerant charge exceeding 1000 kg equipped with au tomatic detection systems combined with

automatic shut-off valves.

• Decommissioning includes reclaim and recovery of refrigerant.

• Companies carrying out maintenance and inst allation work must be certified and their personnel qualified.

The STEK organization was founded in 1991 on the jo int efforts of the government and trade and industry groups in the refrigeration and air c onditioning industries. The aim of STEK was to promote skillful handling of refrigerants and redu ce/prevent refrigerant emissions. In 1992, the Dutch Minister of Housing, Spatial Planning, and the Environment (VROM) transferred the responsibility to STEK for the certification of companies and qualification of personnel, including an inspection and verification system. Only companies with a STEK certificate may carry out work on a refrigeration system.

The success of the Dutch regulations and th e STEK organization in reducing refrigerant

emissions was demonstrated with results from a detailed study in 1999 of emission data from refrigeration and air-conditioning sectors. For co mmercial refrigeration, annual refrigerant emissions (emissions during leakage plus disposal ) were 3.2% of the total bank of refrigerant contained in this sector /Hoo02, STE01/.

Germany In Germany, two articles have reported direct evaporation supermarket systems refrigerant leakage rates in the range of 5-10% per year. A research project ”Tightness of Refrigeration Systems”, was conducted by the Institut fu r Luft- und Kaltetechnik , commissioned by the Forschungsrat Kaltetechnik (Research Council for Re frigeration Technology) /Bir00/. Statistical methods were used to select the refrigeration syst ems to be evaluated, such that representative data could be generalized to all commercial re frigeration systems in Germany. 42 refrigeration systems were selected in Hesse, and 20 systems in Saxony. Refrigerant leak points were identified, and leak rates quantified by use of ha logen leak detectors. There were several findings which provided important insight to refrigerant leakage characteristics.

• No leaks were identified in 40.3% of the systems.

• 14.4% of the leaks contributed 85% of the refrigerant losses.

• 83% of the number of leaks occurred in the assem bly joints, such as flanged and screw joints, plus service valves and sight glasses. From this information, it was obvious that a few “bad” systems caused most of the leakage, and some of their major conclusions to improve system tightness were:

• careful assembly of flanged joints and separable connections,• use improved service valves,

• whenever maintenance is performed, a follow-up leak test is required, and

• use proper leak test procedures and correct evaluation of leak data. For the 19 centralized refrigeration systems built between 1991 to 1999, and having charge sizes of 60 to 300 kg, the leakage data indicated annua l refrigerant loss rate of 9.3% of charge.

The second article /Haa02/ reported on centralized supermarket refrigeration systems using HFC refrigerant R404A in direct expansion for medium and low temperature refrigeration. Data were taken on systems installed in Germany after 1995 with improved technologies for leak tightness, plus reduction of refrigerant fill quantities by 15%. The average leakage rates were determined to be 5% of charge, which is a reduction from earlie r years values of 10% of charge annual rates.

Denmark The Danish Environmental Protection Agency repor ts that new commercial refrigeration systems have become more leak-proof through qualit y improvement efforts of three refrigeration associations. Whereas refrigerant losses were earlier 20-25% of refrigerant charge per year, the new systems are at approximately 10% loss per year /Ped03/.

Norway A Norwegian company of 220 supermarkets provided refrigerant fill data for the time period of 2002 – 2003, showing annual refrigerant losses of 14% of the total bank of refrigerant contained in their supermarkets /Nek04/.

Sweden A large Swedish supermarket chain provided refrige rant fill data from the time period of 1993 to 2002, with annual refrigerant losses decreasing fro m 14.0% in 1993, to 12 .5% in 1998, and to

10.4% in 2001 /Lun04/. The overall lower emission s might be attributed, in part, to increased application of indirect cooling systems in supe rmarkets The annual leakage experiences with the several refrigerants are shown in Figure 1, and th ere are differences in leakage behavior of the refrigerants which might provide valuable learnings . For example, what factors contributed to the lower emission rates of R134a and R407C (3-6 %) compared with R404A (12%)? And what caused the gradual increase of R404A emissions from an initial 3% to a levelling off at 12%? Possible factors might be R404A operation at the more severe low temperature cooling conditions, and/or ageing of piping and valve conn ections, all worthy of further investigation.

United States In the United States, a report by the Environmenta l Protection Agency /Tro 97/ details options for reducing supermarket re frigerant emissions, with four sets of data from supermarket organizations across the United States. The compani es with a total of 349 stores reported average refrigerant loss rates in the range of 8-15% per year in the time period of 1993-1994.

More recent data have shown somewhat higher re frigerant loss rates. Reports of refrigerant emissions for 2001 and 2002 from two supermarket chains located in th e western and eastern United States /Biv04/ showed annual refrigerant leakage losses of 18% and 22% of system refrigerant inventory.

Another source of United States refrigerant emissions data comes from the South Coast Air Quality Management District (SCAQMD), a four county region consisting of Los Angeles and Orange counties and parts of Ri verside and San Bernardino counti es, representing a population of 15 million people in southern California. SCAQMD requires biannual reporting from facilities which have systems containing 22.7 kilograms (50 pounds) or more of CFC and/or HCFCrefrigerants. The reports must include the char ge size, refrigerant type , and annual refrigerant usage for each system in the facility.

Data from the 2000 and 2001 reports are presented below where refrigeration systems have been sorted into seven charge-size groups /Gag04/. Data were available for 223 supermarkets having1164 refrigeration systems in 2000 and 1217 refrigeration systems in 2001. Although the reporting requirements did not apply for systems using HFCs, 5% of the systems reported in 2001 and 2001 used R-404a. The percentage of systems using HCFC-22 declined slightly from 58% in 2000 to 56% in 2001. Table 1 shows the average charge size for each of the seven groups.

Table 1: Number of Systems and Average Charge Size in Refrigeration Systems in the California South Coast Air Quality Management District

Year 2000 Year 2001 Charge Range (kgs) No. Systems Average (kgs) No. Systems Average (kgs)

22.7 to 46 82 36.2 92 35.8

47 to 69 371 65.7 398 64.9

70 to 137 132 108.7 145 106.2

138 to 228 211 209.2 211 209.8

229 to 455 196 347.5 196 347.2

456 to 682 128 613.4 130 612.4

683 to 1285 44 800.4 45 800.8

` Figure 2 shows the percentage of systems in each group which reported no refrigerant usage (and thus no leaks) in a given year. Over the two y ear period, the percentage of systems requiring no refrigerant addition was closely related to syst em refrigerant charge size. 77% of the smaller charge size systems (23-137 kg) required no refrige rant additions, 65% of the medium charge size systems (138 – 455 kg) required no refrigerant additions, and 44% of the larger charge size systems (456 – 1285 kg) required no refrigerant additions. This grad ation is as might be expected, as the larger charge size systems in retail refrigera tion applications have l onger piping runs, more assembly joints, more valves, and therefore mo re opportunities for refrigerant leakage.

Figure 3 shows the annual emission rates for the se veral charge-size systems. On a total system basis, the average emission rates were 13% for 2000, and 19% for 2001. For the small number of R404A systems reported, the average emission ra tes were 9% in 2000 and 8% in 2001. If it can be assumed that R404A is used only in the newer systems, these lower rate s may be an indication of more leak-tight design and construction.

Since the average emission rates include those sy stems with no emissions (as shown in Figure 2), on a per system basis the leaking systems have sign ificantly higher loss rates than the averages. This observation amplifies the importance of peri odic checking with leak detectors, representing a significant opportunity to identify and repair high leakage rate sources.

Other Emissions Data Sources Palandre, Zoughaib, Clodic, and Kuijpers /Pal03/ report creation of databases for refrigeration and air conditioning equipment w ith refrigerant charge sizes to determine global refrigerant inventory, and emission factors for each type of system. Data from their report permits calculation of the worldwide commercial refrigeration refrigerant emission rate for year 2000, that number being 22% of commercial refrigeration systems inventory.The United States Environmental Protection Agency (USEPA) has a Vintaging Model for collection of information on annual market size, gr owth rates, amount of chemical required by each unit of equipment in the model, and hist ory of chemical substitu tion /EPA04/. Emissions from each end-use are estimated by applying emissi on profiles to each vintage of equipment. The model has been applied to include international emissions by using country-specific refrigerant consumption estimates, and by using adjustment factors to United States substitution scenarios, based on differences in growth, rates of phase-out, and refrigerant use patterns. For world-wide commercial refrigeration, the model information has been used to estimate 2015 HFC emissions of 75,000 tons (refrigerant weight basis) for a b aseline case, and 20-30% less if abatement options are fully applied. The abatement options include more aggressive leak detection and repair, and increased use of distributed and secondary loop system s. It is essential that developing countries be assisted with abatement options, as their sh are of worldwide commercial refrigeration HFC

emissions is estimated to be 34% in 2015.

Going into the future, it will be useful for th e two modelling groups to compare their systems inventories and emission estimates, and identif y the more important application sectors and regions of the world for increased emphasis on emission reduction. Based on their publications, there seems to be a reasonable agreement in current global HFC emissions from refrigeration and air conditioning. The Palandre et al paper reports refrigerati on and air conditioning HFC emissions in 2000 of around 70,000 tons. The USEPA paper estimates 2005 refrigeration and air conditioning HFC emissions of 110,000 tons (after conversion from carbon equi valent to tons of refrigerant). These seem to be similar numbers c onsidering industry growth and change-over to

HFCs from 2000 to 2005.

Perspective on Emissions Current refrigerant emissions data for commerci al refrigeration systems as reported in the previous sections vary from 3% to 22% of refrigera nt inventory on an annual basis. The four sets of United States data for three regions of supe rmarkets in the time period of 2000-2002 showed emissions rates of 13%, 18%, 19% , and 22%. Reported European supermarket annual leak rates are at lower values, from 3% in The Netherlands , to 5-10% in Germany, 10% in Denmark and Sweden, and 14% in Norway. Studies have iden tified the main sources of emissions, with recommendations for improved design, installation, and maintenance procedures, including more frequent use of leak detectors. There are add itional routes to lower emission rates, such as distributed systems with shorter piping lengths, and indirect systems in which the primary refrigeration system is coupled with a secondary heat transfer fluid. The indirect systems have additional investment costs and traditionally lower energy efficiency than DX systems, and these

factors will be discussed in the next section.

LIFE CYCLE CLIMATE PERFORMANCE Life cycle climate performance (LCCP) of a refrige ration or air conditioning system includes all of the warming impacts due to the use of the system through its lifetime.

Included are the carbon dioxide emissions from fossil fuel power plants to generate the power to operate the system, plus refrigerant emissions during operation of the system, end-of-life refrigerant disposal losses, refrigerant losses dur ing transport, and embodied energy and trace greenhouse gas emissions from production of the refrigerant.

These components of LCCP were included in cal culations for a supermarket system reported by

A. D. Little /ADL02/. We have taken the basic ex ample described in the report, and added several new variations in supermarket systems. A 5575 square meter ( 60,000 square foot ) supermarket was analyzed using utility emission rate of 0.65 kg CO2 per kWh, yearly refrigeration energy consumption of 1.2 million kWh, and 15 year equipment life. A conventional DX systemoperating with R404A (or R507A) charge of 1636 kg and refrigerant emission rate of 15% per year was initially assumed. Refrigerant manufact uring GWP, 100 year ITH, was taken as 18, for

a total GWP of R404a of 3278.

Several system design changes beyond the b aseline system were evaluated for LCCP.

• DX system with 5% annual leak rate as dem onstrated in Germany and The Netherlands.

• DX system with 5% annual leak rate and re frigerant charge size reduced 40% by critically charging the system.

• DX system with 5% annual leak rate, critically charged with refrigerant R404A, and energy consumption 10% lower than baseline DX system.

• Distributed system with 4% annual leak rate and energy consumption same as DX system; refrigerant charge size 25% of DX.

• Secondary loop system with 4% annual leak ra te; primary refrigeration system charge size 11% of DX, energy consumption 15% higher th an DX system, R404A primary refrigerant

• Secondary loop system as previous, but with ammonia or hydrocarbon as primary refrigerant

• Secondary loop system same as two previous, but with energy consumption only 5% higher than DX system.

The varying conditions chosen for the options in the LCCP table are based on literature reports. As one example, Haaf and Hei nbokel /Haa02/ have reported data from 77 supermarkets installed with secondary loop systems. The secondary loop syst ems had installed costs 15-35% higher than DX systems, and energy consumption 5-20% higher than DX systems.

Table 2: LCCP of Supermarket Refrigeration System Design Options

LCCP, million kg CO2 Configuration Leak Rate Energy Consumption Indirect Direct Total
DX, 1636 kg R404A 15% Baseline 11.7 12.1 23.8
DX, 1636 kg R404A 5% Baseline 11.7 4.0 15.7
DX, 982 kg R404A 5% Baseline 11.7 2.4 14.1
DX, 982 kg R404A 5% -10% 10.5 2.4 12.9
Distr, 409 kg R404A 4% Baseline 11.7 0.8 12.5 Sec Lp, 180 kg R404A 4% +15% 13.5 0.4 13.9 Sec Loop, NH3 or HC 4% +15% 13.5 0 13.5 Sec Lp, 180 kg R404A 4% +5% 12.3 0.4 12.7 Sec Loop, NH3 or HC 4% +5% 12.3 0 12.3

It is recognized that the LCCP values in Table 2 are based on several assumptions such as utility

fuel source and CO 2 emissions rate, and overall system design and performance. There can be differences due to country-specific utility fuel sources, and the state of refrigeration system technology such as laboratory or commercial system demonstrations. The main purpose of the Table is to illustrate the potential magnitude of changes in LCCP for several improvement options. The data show that LCCP can be reduced by up to 50% with the options.

Research is underway in many countries to redu ce LCCP of supermarket refrigeration systems, with expectations for additional improvements in the systems described above, and in more advanced designs such as cascade systems using carbon dioxide as the lower stage refrigerant. Tests of carbon dioxide as the only refrigerant in commercial refrigeration systems are also underway /Sch02; Gir03/.CONCLUSIONS Supermarket refrigeration systems emissions data from several countries show reductions in refrigerant emissions since the earlier losses of up to 35% of system charge per year. Reduced emissions are due to improved systems design, installation, and maintenance procedures, as described earlier in this paper. Additional emissi on abatement options include use of distributed, secondary loop, and cascade systems. Initial investment costs, operating costs, and energy consumption are important factors in considering the several system options. LCCP calculations show the importance of energy efficiency, refrige rant charge size, and refrigerant emissions in reducing the climate change impact of supermarket refrigeration systems. It is essential that developing countries be assisted with abatemen t options, as their share of global commercial refrigeration HFC emissions is estimated to be 34% in 2015.

ACKNOWLEDGMENTS Dave Godwin of U.S. EPA assisted by analyz ing emissions estimates from the EPA Vintaging

Model. David De Boer and his staff at the California South Coast Air Quality Management District provided their district refrigerants database for our use. Petter Neksa of Sintef Engineering, Trondheim, Norway, and Per Lundqvi st of Dept. of Energy Technology, KTH, Stockholm, Sweden, shared emissions data from s upermarket chains located in their countries.

REFERENCES

/ADL02/ A. D. Little, Inc., ”Global Comparative Analysis of HFC and Alternative Technologies for Refrigeration, Air Co nditioning, Foam, Solvent, Aerosol Propellant, and Fire Protection Applications”, report for the Alliance for Responsible Atmospheric Policy, W ashington, D.C., March 21, 2002.

/AEA03/ AEA Technology, ”Emissions and Projections of HFCs, PFCs and SF6 for the UK and Constituent Countries”, report prepared for the Global Atmosphere Division of the UK Department for Environment, Food, and Rural Affairs, July

2003.

/Bir00/ R. Birndt, R. Riedel, and J. Sche nk, “Tightness of Commercial Refrigeration Systems’, DIE KALTE & Klimatechnik, pp 56-63, September 2000.

/Biv04/ D. Bivens, DuPont Fluoroproducts , Wilmington, DE, private communications from supermarket chains in western and eastern United States, 2004.

/EPA04/ U.S. Environmental Protection Agency . "International ODS Substitute Emissions 1990-2020: Inventories, Projections, an d Opportunities for Reductions". Office of Air and Radiation, U.S. Environmental Protection Agency. Washington, DC, April 2004.

/Fis91/ S. K. Fischer, et al, ”Energy a nd Global Warming Impacts of CFC Alternative Technologies”, Alternative Fluorocarbons Environmental Acceptability Study (AFEAS) and U.S. Department of Energy (DOE), Washington, D.C., 1991.

/Gag04/ C. Gage, United States Environmen tal Protection Agency, Research Triangle Park, NC, data from California South Coast Air Quality Management District,

2004./Ger98/ R. J.M. van Gerwen and M. Verw oerd, “Dutch Regulations for reduction of Refrigerant Emissions: Experiences with a Unique Approach over the period 1993-1998”, ASERCOM Symposium: Re frigeration/Air conditioning and Regulations for Environment Protecti on – A Ten Years Outlook for Europe, Nuremberg, October, 1998.

/Gir03/ S. Girotto, S. Minetto, and P. Neksa, “Commercial Refrigeration System with

CO 2 as Refrigerant Experimental Results”, Int. Congress of Refrigeration, Washington, DC, 2003.

/Haa02/ S. Haaf and B. Heinbokel, ”A lternative Refrigerants for Supermarket Refrigeration Installations”, DKV-Tagungsbericht (Proceedings), Volume 2, Issue Pt. 2, pp 29-42, 2002.

/Hoo02/ B. van den Hoogen and H. van der Ree, ”The Dutch Approach to Reduce

Emissions of Fluorinated Greenhouse Ga ses”, IIR Conference, Zero Leakage, Minimum Charge, Efficient Systems for Refrigeration, Air Conditioning, and Heat Pumps, Stockholm, August, 2002.

/Lun04/ Per Lundqvist, Dept. of Energy Technology, KTH, Stockholm, Sweden, private communication from Swedish supermarket chain, 2004.

/Mar98/ March Consulting Group, “Oppor tunities to Minimise Emissions of Hydrofluorocarbons (HFCs) from the European Union”, EC DG3 HFC Study, UK, September, 1998.

/Nek04/ P. Neksa, Sintef Engineering, Trondheim, Norway, private communication from Norwegian supermarket chain, 2004.

/Ped03/ Per H. Pedersen, ”Evaluation of the possibilities of substituting potent greenhouse gases (HFCs, PFCs and SF6)”, Environmental Project No. 771, Danish Environmental Protection Agency, 2003.

/Pal03/ L. Palandre, Assaad Zoughaib, D. Cl odic, and L. Kuijpers, ”Estimation of the world-wide fleets of refrigerating and ai r-conditioning equipment in order to determine forecasts of refrigerant emi ssions”, The Earth Technology Forum, Washington, D.C., April 2003.

/Sch02/ P. Schiesaro and H. Kruse, “Development of a Two Stage CO 2 Supermarket System”, New Technologies in Commercial Refrigeration, IIR Conference, Urbana, IL, July 2002.

/STE01/ ”Consumption of refrigerants in the Netherlands”, report based on the National Investigation on Refrigerant Flows, Zero measurement for 1999, STEK, 2001.

/Tro97/ E. F. Troy, ”Options for Reducing Emissions from Supermarket Systems”, report for U.S. Environmental Protection Agency, EPA-600/R-97-039, Washington, D.C., April 1997.

/UNE02/ United Nations Environment Programme, ”2002 Report of the Refrigeration, Air Conditioning and Heat Pumps T echnical Options Committee”, 2002.

### Figure 2: Percentage of Systems with no Refrigerant Addition

(California South Coast Air Quality Management District)

62% 83% 83%

74%

69%

53%

36% 84%

78%

72%

61%

57%

44% 44%

0% 10% 20% 30% 40% 50% 60% 70% 80% 90%

23 to 46 47 to 69 70 to 137 138 to 228 229 to 455 456 to 682 683 to 1285 2000

2001

Charge Size (kgs) 

### Figure 1: Swedish Supermarket Company Annual Refrigerant Leakage as % of Charge

0 5 10 15 20 25

1992 1993 1994 1995 1996 1997 1998 1999 2000 2001 2002 2003Leakage, % of charge

R502 R12

R404A R22

R134a R404A

R407C

### Figure 3: Annual Refrigerant Emission Rates

(California South Coast Air Quality Management District)

24%

10% 11% 10% 11% 16%

13% 13% 13% 16% 17% 23%

19%

18%

16% 19%

0% 5% 10% 15% 20% 25% 30%

23 to 46 47 to 69 70 to 137 138 to 228 229 to 455 456 to 682 683 to 1285 All Systems Charge size (kgs) 2000

2001