Can I Replace R-22 in My Rooftop AC Unit With R12?

EPA Listings

• R-12 is a refrigerant for automobile air conditioners and is not compatible with rooftop AC units or other home air conditioners. At the time of publication, the EPA listed government-approved alternatives for R-22, but R-12 is not included. R-12 is also considered harmful to the environment.

Damage

• R-12 and R-22 harm the stratospheric ozone layer when released into the air, according to the New Hampshire Department of Environmental Services. Title IV of the U.S. Federal Clean Air Act makes it illegal to knowingly release these refrigerants into the atmosphere. The refrigerants can thin the ozone layer and increase levels of ultraviolet radiation at ground level. As a result, automobile manufacturers and heating and air conditioning contractors are moving on to other refrigerants that are safer for the environment.

Help

• It is usually best to allow a trained technician to make suggestions for recharging your rooftop AC unit. The task is complex for people without training. Failing to properly charge your unit could cause it to perform poorly. A bigger concern is personal safety. Working on an HVAC system could expose you to deadly levels of electrical shock or deep cuts from the fan on the rooftop unit. If you are experiencing a performance problem with the rooftop unit, it is possible that a lack of refrigerant is not the issue. Parts in the unit, such as the compressor or capacitors, may have failed causing the overall system to malfunction. A trained technician can review all possibilities. The technician can also suggest a substitute EPA-approved refrigerant.

Leaks

• There’s no reason to remove R-22 from your rooftop AC if the unit is working. Government guidelines on R-22 and R-12 do not require removal from systems currently in use. Refrigerant usually escapes from systems only if there is a leak. An HVAC technician can conduct tests that determine if your rooftop system has leaks. That issue should be addressed before adding more refrigerant.