Heat of Compression

As a gas is compressed its temperature is raised. The gaseous refrigerant return­ing to the compressor from the cooling coil will probably be at or slightly below the room temperature. This same gas, as it leaves the compressor and enters the condenser will be at a much higher tem­perature. Little or no heat has been added. 

However, the total heat of the gas is now squeezed into a much smaller space, and a much higher temperature results. This is called "heat of compression," although, technically, no heat has been added. In the compression of gaseous refrigerant in a refrigerator, the compressor is considered to be near a state of adiabatic compression. See Par. 1-54 for a definition of Adiabatic Compression. The fact that the compressed gas in the condenser is now at a tempera­ture higher than the temperature of the surrounding air, the heat will be rapidly transferred to the surrounding air.