Refrigerant is the life-blood of an air conditioning system. In fact, the role refrigerant plays in an AC is similar to the role of blood in the human body: it circulates from a pump and allows the AC to transfer heat from one place to another. Cold refrigerant in the evaporator coil absorbs heat to lower the indoor air temperature, and hot refrigerant in the condenser coil releases heat to the outside. This process is called heat exchange, and the chemical refrigerant is designed to make this as efficient as possible.
As you may imagine, refrigerant leaking from an air conditioner is a problem, and not just because it will make it harder for the AC to remove heat from the house to the outside. A loss of refrigerant will eventually cause catastrophic damage to the air conditioner and lead to a burnt-out compressor.
