We design behind cold rooms that allows them to function efficiently isn’t so different from any other refrigeration system. Cold rooms use a compressor, condenser, fans, and an evaporator to maintain temperature within the unit. 

After a gas refrigerant gets compressed in the compressor it expands, and the gas absorbs energy. The hot gas flowing from the compressor passes over the evaporator coils and, after liquifying under high pressure, this cools the evaporator coils and the surrounding air. In order to maintain temperature, cold rooms must also be efficiently insulated.