My Central Air Unit Is Leaking White Foam

Source

• If your air conditioner appear to be leaking a white foam, chances are it is coming from one of the system's refrigerant lines. The only type of substance used by the air conditioner that could conceivably consist of any substance that could form a white foam would be the refrigerant itself. Refrigerants are the cooling agents or gases that are put into an air conditioning system to turn warm air into cold air.

Operation

• A central air conditioning system operates on the same principles as a window unit or even a refrigerator. The compressor is the central piece of equipment needed for the cooling action. The compressor is responsible for compressing the refrigerant gases into liquid form by applying intense pressure to them until they change from their gaseous state. Once this happens, the compressor shuts off and the liquified refrigerant begins to expand once again. As it expands, it cools. Cold air is then exchanged for warm or hot air in the air conditioner's air exchange and blower unit, which then distributes the colder air throughout the house.

Leaks

• Leaks are not as common in air conditioners as people often assume. In actuality, the refrigerant system is a closed system and the gases never really dissipate or just go away on their own. Instead, there needs to be some sort of damage to one of the lines or the compressor that causes the refrigerant to leak out. Because the refrigerant can be in both liquid and vapor form, it will appear differently, depending upon the state that it is in at the time of the leak. Refrigerant that is in liquid form or in the process of transforming from liquid to gas may appear as a foamy substance. As it interacts with the oxygen in the air, the refrigerant will begin to bubble and foam on the refrigerant line where the leak occurs. This is similar to the reaction that you see when you use hydrogen peroxide on a cut or scrape.

Service

• If you discover a leaking foam substance coming from your refrigerator lines, you will likely need to contact a professional service technician to fix the problem. Government regulations regarding the use of refrigerants make this necessary. Your system will likely need to be resealed and charged. The cost of a service call is well worth the money you'll spend. This is one of those fixes that you probably shouldn't try on your own.