Definition for word: Refrigerant

 A substance that remains a gas at low temperatures and pressure and is used to transfer heat in heat pumps and air conditioners.

Referrence from

A refrigerant is a substance used in a heat cycle usually including, for enhanced efficiency, a reversible phase change from a gas to a liquid. Traditionally, fluorocarbons, especially chlorofluorocarbons were used as refrigerants, but they are being phased out because of their ozone depletion effects. Other common refrigerants used in various applications are ammonia, sulfur dioxide, and non-halogenated hydrocarbons such as methane.

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