22 May 2002
In response to global environmental threats industry has developed and introduced replacement refrigerants with zero ozone depletion potential and low global warming potential. In most cases hydrofluorocarbons (HFCs) have been found to be the ideal replacement. In some applications, hydrocarbons (HCs) or ammonia have been found to work well. Hydrocarbons, ammonia and some HFCs are flammable and special precautions must be taken to ensure the safety of the building occupants, the service technicians and the general public. This paper will focus on refrigerant flammability. With the introduction of equipment using flammable refrigerants it has become necessary to modify some standards to allow for the safe use of flammable refrigerants. Methods of determining the lower flammability limits of refrigerants are being updated and research programs are underway to evaluate the potential risk in the event of a leak.