Propane use in household air conditioners is prohibited by the EPA.
The emergence of propane as a refrigerant is primarily due to the phasing out of chlorofluorocarbons (CFC's) that began in 1995 and the push to regulate greenhouse gasses. Pure propane has no ozone depletion potential and is a very inefficient greenhouse gas. it's also a means of refrigeration that doesn't require connection to the electricity grid. Propane is a hydrocarbon; often blended to form a series of hydrofluorocarbon mixtures to get desirable qualities. The EPA regulates propane and its compounds in both moving and stationary refrigerant sources.
Automobile Propane Refrigerant
The EPA strictly regulates all automobile refrigerants. Propane and hydrocarbon refrigerants are illegal for use in automobiles, as of August 2010, mainly because of concerns about their flammability. Despite this, propane related compounds still exist in some automobiles and recovery and reclamation of propane refrigerant is encouraged. As stated on the EPA's website, auto technicians must use a standard DOT certified tank for recovery. If the tank doesn't have a float valve it can't be filled to over 60 percent of its gross weighted capacity. Certified centers can legally reclaim propane gas mixes from automobiles, though it's difficult for typical auto repair shops to identify specific gas compounds without expensive equipment.
Industrial Applications
The EPA's Significant New Alternatives Policy (SNAP) program accepted propane as acceptable for industrial process refrigeration affective June 16, 2010. This applies to both retrofits and new refrigeration purposes. It replaced two ozone-depleting compounds, as part of the final phase of ending the use of such gasses. Industrial applications include things such as process chilling, industrial ice machines, pumping systems and coolers used in grocery stores and restaurants. Prohibiting of the venting of propane continues.
Household Applications
Many parts of the world allow manufacturers to use propane in refrigeration of domestic sized air conditioners and heat pump units. As of August 2010, the EPA still does not allow propane for these applications. Consideration of these applications took place when SNAP legalized propane for industrial use, but the EPA decided against them. The SNAP board points out in their review on the U.S. Government Printing Office website summary.
