Let’s begin with the compressor. As the engine of the refrigerant cycle, it takes the low pressure, low temperature gas from the indoor evaporator coil and turns it into a high pressure, high temperature gas, one that is substantially higher than the outside temperature. It then travels to the condenser coils to be dissipated into the outside air with the help of an exhaust fan. It has now been condensed (hence the name), but it is not yet cool enough. It flows into an expansion valve where it cools rapidly and now can be used as a material for cooling. The evaporator coil circulates this cold, liquid refrigerant and the thermal interaction that occurs between the refrigerant and the warm indoor air causes the refrigerant to turn into a gas. Hence the cycle continues.
For a long time, R-22 (also known as Freon) was the standard in the HVAC industry, but it has since been exposed as a potential environmental hazard, and is now being phased out of production. Because today’s refrigerants are not able to be retrofitted into systems designed to handle this older standard, it’s important to recognize how this phase-out could affect you.