Refrigerants substances with a low boiling point and a large latent heat, at a pressure above atmospheric pressure. Refrigerants typically fall into one of the following groups:
CFC - chloroflurocarbons;
HCHCs - hydrochlorofluorocarbons;
HFCs - hydrofluorocarbons;
HC - hydrocarbons;
NH3 (ammonia.
CFCs destroy the stratospheric ozone, and after the Montreal Protocol, are no longer produced. HCFCs also Deplete the ozone, but to a lesser degree, and will be phased in Europe by 2015. Small quantities are manufactured under the strict regulation for multiple legacy systems. Developing countries were granted more time for the transition. Therefore, new refrigerating systems with HCFCs will continue to be sold in developing countries. HFCs, which were developed in the 1990s to replace CFCs and HCFCs. Housing is also used as a replacement.
Refrigerants consume energy during the manufacturing process and refrigeration, also contribute to global warming, as they consume electricity and other fuels in operation.
Fuel combustion in power plants or refrigeration equipment leads to emissions of carbon dioxide, which is a greenhouse gas that contributes directly to global warming. The total direct and indirect effects of global warming refrigerants is called total Equivalent Warming Impact (TEWI) value.
Many new refrigerants mixture of different substances, which fall into two categories:
Those with low ODP, which are used as transitional substances, they are usually designed based on the mixture of HCFC R22 (e.g. R409A, R411B)
Those with zero ODP), which in the long term, these, as a rule, on the basis of HFCs (e.g.. R404A, R407C), or utilities (e.g.. Care 30, Care 50).
Transitional substances are mainly used for the conversion of existing systems. They must not be set for the new equipment. As they relate R22, they can work with the existing mineral oil in the system and the conversion procedure is relatively simple.
Based on the mixture of HCFC or utilities can be used to replace CFC, HCFC or refrigerant in existing systems without an oil change. Based on the mixture of HFC is typically only used in new systems...
Chillers 