Does a Car's A/C Freon Eventually Run Out?

Freon is the brand name of a type of air-conditioning refrigerant gas manufactured by DuPont Chemicals. Other brands of R-22 refrigerant gas are made by other manufacturers. Over the years the chemical structure of these refrigerant gases like R-12 or R-14 have been replaced in general usage in response to environmental regulations by the United States Environmental Protection Agency.

Your car's air-conditioning system compresses refrigerant gases into a liquid, then releases the gas through a radiator-like evaporator coil. The sudden expansion of the gas chills the evaporator coils. This draws heat from air passing over the coils and out through the air-conditioner vents inside the car, cooling the interior of the vehicle. Refrigerant gas does not “wear out” like oil nor is it used up like fuel. In a properly sealed system the gas can continue being compressed and released over and over, so long as it doesn't leak out.

The inside of an engine compartment, where the air-conditioning system operates, subjects the hoses and connections of the system to extremes of temperature and vibration, as well as contact with pollution, road grime, fuel, oil, and abrasive and corrosive substances. Over time, these factors break down the hoses and connections, causing the pressurized refrigerant gas to leak out.

You will likely first notice refrigerant gas loss when your air conditioner stops cooling as well as it should. At low levels, the evaporator coils can ice up. Refrigerant gas often has a dye tag that may show up around hoses and connections as a red fluid. Chronic low levels of refrigerant gas can cause the air-conditioner compressor to heat up and damage it permanently.

A relatively small loss of refrigerant gas can reduce the efficiency of your air-conditioning system dramatically. A 10-percent loss of refrigerant gas can reduce the efficacy of your air conditioner by 20 percent or more. You can prevent this loss by having your system checked annually prior to the start of hot weather. Have lost refrigerant gas replaced by professionals. Overcharging the system can be as damaging as chronic refrigerant gas loss. Some auto AC professionals recommend evacuating the system and refilling it every three to four years in order to test for leaks.

Bear in mind that federal -- and many state -- laws prohibit the knowing release of Freon into the atmosphere. If your car has a leak, you are legally obligated to have the leak repaired before recharging the system.