Casteel Heating and Cooling offers Free Refrigerant with some restrictions. This page explains the refrigeration cycle and a little history of the gases that work to keep us comfortable.
In heating and cooling equipment refrigerants (R-22) and Puron (r410A) are used to transfer heat through compressing and evaporating the gases in the contained lines. When the gas is compressed the pressure rises and becomes hot in a liquid state and mixed with a small amount of oil, then it’s passed though coils designed to give plenty of surface area so that the gas can cool down. It is passed through an expansion valve which causes the gas to cool down until it evaporates in the evaporator coil. Here warm air is pulled out of the home by the return air ducts and the central blower unit (furnace or air handler) and passed over the evaporator coils. The gas which has evaporated out of its liquid state is now cool and absorbs the heat from the air being passed over the coil. The air is now cooler and is pushed back into the home via the air delivery system (duct work) and the gas continues the cycle outside to be compressed into a liquid again releasing the heat outside at the condenser.
In accordance with terms and agreement reached in the Montreal Protocol (The Montreal Protocol on Substances that Deplete the Ozone Layer) the United States Environmental Protection Agency has mandated that production or import of R-22 along with other hydrochlorofluorocarbons (HCFCs) be phased-out in the United States. In EU and the USA, virgin R22 cannot be used for manufacture of new air conditioning or similar units from 1 January 2010. In other parts of the world the phase out date varies from country to country. Today, all newly manufactured window unit air conditioners and central air conditioning systems in the United States come with R-410A. As an alternative to window-mounted systems, a ductless "split" system is available which also uses R-410A refrigerant.