A Guide to All You Need to Know About Freon

Laura Hennigan
Written by Laura Hennigan
Updated January 17, 2022
woman relaxing on couch adjusting ac
Photo: fizkes/ Adobe Stock


  • Older model appliances often utilize Freon as a refrigerant.

  • You’ll find Freon in air conditioners and refrigerators.

  • Freon leaks are not common, so there are a few signs to watch out for.

  • Professionals utilize a few different methods to help diagnose a Freon leak.

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You likely don’t give much thought to the inner workings of the appliances in your home. Most people take for granted that icy air blows when they turn on the AC or that the milk in the refrigerator always stays cold enough.An important component of these conveniences is Freon, a refrigerant designed to help keep things cool. But Freon is also susceptible to occasional leaks, leading to other potential issues. 

What is Freon?

Freon is the registered brand name of liquids and gases used for refrigeration purposes. Air conditioners, refrigerators, chest freezers, and dehumidifiers use Freon. A 25-pound canister of Freon costs $75 to $175 per pound, and most systems need 6 to 15 pounds. 

Note that this is a powerful coolant; let a certified technician handle Freon. It is also a substance that is being phased out, and the EPA began banning the use of Freon in new appliances in January 2020. New AC units use R-410A refrigerant, which costs about $3 to $8 per pound

How Does Freon Work?

Depending on the appliance or unit, Freon works in a few different ways:

Air Conditioners 

Air conditioning systems contain a compressor, which compresses Freon gas and increases its temperature. The gas then moves into the AC coils, cooling it into a liquid form. The cooled Freon then absorbs the heat from the outside air and pushes the cold air out to cool your home. Don’t ignore possible freon issues, as the leaks can still occur even if your AC is off.


Freon attaches to the compressor line in a refrigerator and then pushes through the coils. Refrigerators work by causing the coolant circulating inside them to change from a liquid into a gas. This evaporation process cools the surrounding area and keeps the refrigerator air at the desired temperature.

How Long Does Freon Last?

Freon in a normal AC unit should last 10 to 20 years. Your system should not lose more than a pound every few years or more; many systems go their entire life without needing the addition of gas.

How to Know if You Have a Freon Leak

outdoor ac unit with freon tank
Photo: JJ Gouin/ Adobe Stock

Air conditioners and refrigerators offer a few telltale signs if they aren’t working properly. These are some possible indicators of a freon leak:

Air Conditioner 

  • Warm air: If the vents in your house are blowing warm air, there may be a leak

  • Unusual noises: Hissing or bubbling sounds can indicate a Freon leak

  • Frozen coils: Frozen evaporator coils can signal a leak issue


  • Musty smell: Any new, unusual musty smells may be a sign of a Freon leak

  • Residue: Visible residue on the floor around the fridge may be Freon that has leaked out

  • High temps: Fridge temperatures reading higher than normal

 How Long Does It Take for Freon to Leak Out?

Depending on the appliance's age, the size of the hole, and the amount of coolant in the unit, it can take 30 minutes to six hours for Freon to leak out of an AC or refrigerator. Because AC units and refrigerators are closed systems, their freon should last quite some time, unless there is a leak. If your appliances aren’t performing as well, or you notice higher temperatures, there is likely a leak somewhere that needs attention. 

How to Detect a Freon Leak

An AC inspection by a professional HVAC tech will cost anywhere from $50 to $200. Freon likes are the most common evaporator coils, but they can also occur in valves, “U” connectors, or the copper lines and tubing.  

When calling in a professional to investigate a potential Freon leak, they may detect in one of a few different ways:

  • Bubbles: Soapy water is applied to the suspected Freon leak and will bubble up if there is a leak

  • UV dye: A tech will add ultraviolet dye to the refrigerant, which will light up in any detected leaks

  • Electronic detector: A calibrated device will detect any leaks; this is a highly accurate method

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