Climate Change 2001: Working Group III: Mitigation

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A3.2 Refrigeration, Air Conditioning, and Heat Pumps

Most current and projected HFC consumption and emissions is in this sector. HFC consumption in refrigeration and mobile and stationary air conditioning in 1997 was, on a mass basis, about 30% of projected developed country CFC consumption in the absence of the Montreal Protocol (McFarland, 1999). Most of the remaining 70% of projected consumption has been eliminated by reducing leaks, reduced charge per application, and improved service practices; the substitution by other fluids and new technologies played a lesser role (some substitution – a few per cent – by HCFCs also took place). Globally, there is still a huge potential to further reduce HFC emissions. Estimated consumption and emissions of HFCs for this sector for 2000 and 2010 are shown in Table A3.2. Emissions significantly lag consumption because HFC systems are relatively new so emissions will occur well after 2010.

Table A3.2: Estimated and projected global HFC consumption and emission for different sub-sectors for 2000 and 2010
Sub-sector	2000				2010
	HFC consumption	HFC consumption	HFC emission	HFC emission	HFC consumption	HFC consumption	HFC emission	HFC emission
	kt/yr	MtCeq/yr	kt/yr	MtCeq/yr	kt/yr	MtCeq/yr	kt/yr	MtCeq/yr
Refrigeration & A/Ca,b Mobile A/Cc Domestic refrigerationf Comm. refrigerationd, e, f Cold storaged Industrial refrigerationd Chiller A/C Transport refrigerationd, e, f Unitary air conditioning	102-112 64-74 7 19 4.5 1.5 2.5 3.3 -	47-50 23-26 2.5 15 3 1 1 1 -	40-44 31-35 0.9 5 1.2 0.3 0.2 1.3 -	18-19 11-12 0.3 4.5 0.8 0.2 0.1 0.7 -	195-255 58-79 15-17 46.5-64 9-12 3-4 3.5-4.5 17-23.5 43-51	106-139 21-28 5.5-6.4 39-54 6-8 2-2.7 2.3-3 8.5-12 22-25	82-124 37-54 3.5-4.5 19.5-31 3-4 0.6-0.8 0.5-0.7 10-14.5 8-14	42-64 13-19 1.3-1.7 16-26 2-2.5 0.4-0.5 0.3-0.5 5-7 4-7
Insulating foamsg Solvents/ cleaningh Med. aerosolh Other aerosolh Fire protectiona,b,i	4+ <2 1 <15 1.0 - 1.6 0.6 - 0.9	1.5+ <9 <1 <4 0.8 - 1.3 0.5 - 0.8	<1 <2 1 <15 0.2-0.4	<0.5 <9 <1 <4 0.2 - 0.3	115 >2 <9 <20 1.6 - 2.0	29.5 <9 <4 <5 1.3 - 1.7	20-40 >2 <9 <20	5-10 <9 <4 <5
TOTAL	125-136	63-66	59-62	32-33	343-403	155-189	134-196	66-93
a Consumption and emission estimates are based on information contained in (UNEP, 1998a, 1999b); A/C = Air Conditioning b The average growth has been estimated as 2.5% annually over the period 2000-2010 c See text and Table A3.3 for explanations d The mix of refrigerants (both pure HFCs and HFC blends) is estimated based on information in (UNEP, 1998a, 1999b) for commercial, cold storage, industrial and transport applications e 2010 emission factors have been defined as 7%-10% for commercial refrigeration, 12%-18% for transport refrigeration; f Equipment life for domestic refrigeration is assumed to be 15 years or longer implying that no emissions at disposal will occur by the year 2010. Equipment life for commercial and transport refrigeration is assumed to be 10 years with between 60% and 80% emitted (20%-40% recovery) at disposal g Emissions for insulating foam were based on a methodology described in Gamlen et al., 1986 h Emissions of HFCs used as solvents and medical and other aerosol propellants occurs within one year of consumption (Gamlen et al., 1986) i Emissions for the fire protection sector for 2000 are estimated to be 5% of the installed base (the same level as the average halon emission in the recent decade); for the year 2010 they are assumed to be 2.5% of the installed base, as a result of improved design and service practices (IPCC/TEAP, 1999; UNEP, 1999b).

The primary options for limiting HFC emissions are the use of alternative refrigerants and technologies, reduced refrigerant charge, improved containment, recovery with recycling, and/or destruction. There are no globally representative estimates of the cost effectiveness of improved containment and recovery. In developed countries, recovery during servicing of small domestic refrigerators captures a relatively insignificant proportion of HFCs, while end-of-life recovery is significant. For medium-sized devices such as commercial units with substantial leakage rates, recovery during both multiple servicing and at the end of useful life is both significant. For very large units recovery both during servicing and at end of life is frequently done already because of the high economic value associated with the large quantities of recovered fluids.

In developing countries, where low cost is important, the quality of equipment is often poor, resulting in high failure rates. Since the service sector in developing countries is normally not equipped with the tools for recycling, the emissions of refrigerants during servicing and product disposal form a significant portion of the overall emissions.

Recovery at theend of equipment life is likely to exhibit a poor cost-effectiveness for smaller units. For these units, the introduction of economic incentives will be necessary, probably together with voluntary agreements and/or government regulations (as already exist in some countries) to achieve significant reductions in this sector.

Carbon dioxide emissions associated with energy consumption by refrigeration, air conditioning, and heat pump equipment are usually the largest contributions to global warming associated with cooling equipment (AFEAS, 1991; Papasavva and Moomaw, 1998). Japanese manufacturers estimate that energy-related CO₂ emissions represent an even larger fraction of lifetime emissions for their low leakage rate, small charge appliances. Thus, improvements in equipment energy efficiency are often a cost-effective way to reduce greenhouse gas emissions and to lower costs to consumers (March, 1998). Proper equipment design, component performance, and the selection of the most appropriate refrigerant fluid are the most important factors contributing to energy efficiency. Examination of the LCCP of the system will determine which combination of operating efficiency and fluid choice yields the lowest overall contribution to global warming.

Hydrocarbons, carbon dioxide, and to a lesser extent, ammonia are the most likely alternatives to HFC refrigerants. No ammonia vapour compression units have capacity less than 50kW. Since both hydrocarbons and ammonia are flammable and ammonia is toxic, their acceptance will depend on cultural norms and specific regulations in each country. Hydrocarbons are currently being used in about 50% of the refrigerators manufactured in Europe and in some manufactured in Asia and Latin America; their use in these products as well as in other refrigeration and air conditioning systems could increase. Large charges can present a safety concern, and globally standardized mechanical and electrical safety standards are being established.

If safety is a concern, secondary loops containing a heat transfer fluid can be used. For modest cooling, such as water chilling for residential air conditioning or industrial process chilling, there is no energy penalty from using a secondary loop. For medium temperature applications in food processing and commercial refrigeration, secondary loops permit the safe use of ammonia and hydrocarbons, or enable minimization of an HFC refrigerant charge, generally with a modest energy penalty. If safety concerns require a secondary loop for low temperature applications in food processing and cold storage, in which normally the refrigerant is used as the direct heat transfer fluid, a substantial energy penalty may ensue.

Where they are required, the estimated cost of utilizing secondary loops with ammonia and hydrocarbons to replace HFCs is estimated to exceed US$100/tC_eq (Harnisch and Hendriks, 2000). Secondary loop systems designed to achieve comparable efficiency and demonstrated in Europe have up to a 15% higher cost.

An optimal transition strategy from ODSs to alternatives can substantially lower costs and better meet development goals for developing countries, especially in the refrigeration and air conditioning sectors (Papasavva and Moomaw, 1997). The Montreal Protocol Multilateral Fund (MLF) and the Global Environment Facility (GEF) have just begun to coordinate financing of ozone and climate protection (IPCC/TEAP, 1999). To date, one project has been jointly funded by the MLF and the GEF, which addresses energy efficiency in the replacement of CFCs. Energy use forms a major problem for the stressed energy supply system of capital-strapped developing countries. Since the greatest growth in refrigeration and air conditioning is projected to occur in developing countries, it is important that they select the most effective (in terms of costs and energy efficiency) non-ODS technology. Currently, customers in developing countries make purchase decisions based on initial cost with little consideration of energy consumption.