The refrigeration of chilled foods 83 in the atmosphere by, particularly, carbon dioxide and water vapour. Fears of excessive global climate change are associated with high emissions of carbon dioxide(mainly from burning fossil fuels in power stations and elsewhere)and of other more powerful but much less abundant 'greenhouse gases including HFCs(hydrofluorocarbons) Under the auspices of the Montreal Protocol(Anon. 1987), the developed world ceased the production of ozone-depleting CFCs during the 1990s. This was made possible by the substitution of less environmentally harmful HCFCs The HCFCs themselves are expected to be phased out by 2010-20, if not earlier and in some applications there are no known effective substitutes at present available In Europe, the use of CFCs in existing equipment will be banned, and the supply of new equipment using HCFCs will be prohibited. At the time of writing. dates for these limitations are still uncertain. These matters have two direct impacts on users of chilling equipment. Firstly, every change of technology costs money, and may in some cases result in an increase in running costs as well as re-equipment costs. Secondly, it may be necessary in the future to move from locally safe but globally harmful CFCs and HCFCs to globally safe but potentially locally hazardous substances such as ammonia and propane. These latter substances can be used safely, but there are added costs and added needs for proper training of equipment users. HFCs(hydrofluoro- carbons) have been developed as alternatives. These do not deplete ozone and are widely available, but are being targeted by some environmentalists, as they are greenhouse gases within the Kyoto Protocol The purchaser of equipment needs to be aware of these matters, as he may otherwise obtain machinery that will have to be modified or even replaced long before its expected economic life is over. There could also be financial implications at the time of machinery disposal. The reduction of CFC and HCFC use in insulating foams in storage cabinets and stores has been well publicised but at the time of writing the implications for refrigeration machiner fficiently widely appreciated A further related issue is the relation between global warming, energy nd energy efficiency. New refrigerant fluids may be less efficient, but future environmental concerns may penalise excessive energy use. The equipment specifier is likely to face some difficult choices over the next few years. The user will face new responsibilities for minimising refrigerant leakage, ensuring fficient operation, and using only properly qualified maintenance staff. For a fuller discussion see(Heap 1998) 4.5 Chiled foods and refrigeration The benefit of chilled storage is the extension of life of the foodstuff in good condition, by slowing down the rate of deterioration. Chilling, it must be emphasised, cannot improve the quality of a poor product, neither can it stop the processes of spoilage- it can only slow them down(see Chapters 7, 9, 10)in the atmosphere by, particularly, carbon dioxide and water vapour. Fears of excessive global climate change are associated with high emissions of carbon dioxide (mainly from burning fossil fuels in power stations and elsewhere) and of other more powerful but much less abundant ‘greenhouse’ gases including HFCs (hydrofluorocarbons). Under the auspices of the Montreal Protocol (Anon. 1987), the developed world ceased the production of ozone-depleting CFCs during the 1990s. This was made possible by the substitution of less environmentally harmful HCFCs. The HCFCs themselves are expected to be phased out by 2010–20, if not earlier, and in some applications there are no known effective substitutes at present available. In Europe, the use of CFCs in existing equipment will be banned, and the supply of new equipment using HCFCs will be prohibited. At the time of writing, dates for these limitations are still uncertain. These matters have two direct impacts on users of chilling equipment. Firstly, every change of technology costs money, and may in some cases result in an increase in running costs as well as re-equipment costs. Secondly, it may be necessary in the future to move from locally safe but globally harmful CFCs and HCFCs to globally safe but potentially locally hazardous substances such as ammonia and propane. These latter substances can be used safely, but there are added costs and added needs for proper training of equipment users. HFCs (hydrofluoro￾carbons) have been developed as alternatives. These do not deplete ozone and are widely available, but are being targeted by some environmentalists, as they are greenhouse gases within the Kyoto Protocol. The purchaser of equipment needs to be aware of these matters, as he may otherwise obtain machinery that will have to be modified or even replaced long before its expected economic life is over. There could also be financial implications at the time of machinery disposal. The reduction of CFC and HCFC use in insulating foams in storage cabinets and stores has been well publicised, but at the time of writing the implications for refrigeration machinery are insufficiently widely appreciated. A further related issue is the relation between global warming, energy use, and energy efficiency. New refrigerant fluids may be less efficient, but future environmental concerns may penalise excessive energy use. The equipment specifier is likely to face some difficult choices over the next few years. The user will face new responsibilities for minimising refrigerant leakage, ensuring efficient operation, and using only properly qualified maintenance staff. For a fuller discussion see (Heap 1998). 4.5 Chilled foods and refrigeration The benefit of chilled storage is the extension of life of the foodstuff in good condition, by slowing down the rate of deterioration. Chilling, it must be emphasised, cannot improve the quality of a poor product; neither can it stop the processes of spoilage – it can only slow them down (see Chapters 7, 9, 10). The refrigeration of chilled foods 83