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Hydrofluorocarbons (HFCs) and to a lesser extent perfluorocarbons (PFCs) have been introduced to replace ozone-depleting substances (ODSs) that are being phased out under the Montreal Protocol on Substances that Deplete the Ozone Layer. HFCs and PFCs have a significant global warming potential (GWP) and are listed in the Kyoto Protocol. This Appendix estimates consumption and emissions and assesses alternative practices and technologies to reduce emissions. Emissions as by-products of manufacturing are treated in the main part of Chapter 3.
In the absence of the Montreal Protocol the use of chlorine- containing compounds and especially CFCs would have expanded significantly. However, because of this treaty, developed countries replaced about 8% of projected chlorofluorocarbon use with HFCs, 12% with HCFCs, and eliminated the remaining 80% by controlling emissions, specific use reductions, or by using alternative technologies and fluids including ammonia, hydrocarbons, carbon dioxide, water, and not-in-kind options.
In 1997, the production of HFCs was about 125 kilotons (50MtCeq), and the production of PFCs amounted to 5 kilotons (12MtCeq). The production of HFCs in 2010 is projected to be about 370 kilotons or 170MtCeq and less than 12MtCeq for PFCs, assuming current trends in use and regulations, substantial investment in new HFC production capacity, and success of voluntary agreements. Since most of the HFCs and some of the PFCs are contained in equipment or products, annual emissions lag production when use is growing.
Refrigeration, air conditioning, and heat pumps are the largest source of emissions of HFCs. Improved design, tighter components, and recovery and recycling during servicing and disposal can reduce lifetime HFC emissions at moderate to low costs. Non-HFC alternatives include hydrocarbons, ammonia, and carbon dioxide, or alternative technologies. Lifecycle climate performance (LCCP) analysis of the entire system, including direct fluid emissions and indirect emissions from carbon dioxide resulting from energy use by the device, provides a means of assessing the net contribution of a system to global climate change. The LCCP calculations are very system specific and can be used to make relative rankings. However, since the LCCP approach involves regional climate conditions and local energy sources, the results cannot be generalized in order to make globally valid comparisons.
Insulating foams are anticipated to become the second largest source of HFC emissions and HFC use is expected to grow rapidly as CFCs and HCFCs are replaced with HFC-134a, HFC-245fa, and HFC-365mfc. Alternative blowing agents including the different pentanes and carbon dioxide have lower direct climate impact from direct emissions. However, they also have lower insulating values than CFCs and HCFCs, and hence may have higher indirect emissions from energy use if the foam thickness is not increased to offset the higher conductivity. Non-foam insulation alternatives such as mineral fibres are also used, and vacuum panels may play a role in the future.
Other sources of HFC and PFC emissions are industrial solvent applications, medical aerosol products, other aerosol products, fire protection, and non-insulating foams. A variety of options are available to reduce emissions including increased containment, recovery, destruction, and substitution by non-fluorocarbon fluids and not-in-kind technologies. There are no zero- or low-GWP alternatives for some medical and fire protection applications.
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