There’s a reason why the compressor is known as the “heart” of a typical air conditioning system. It’s responsible for pumping refrigerant through the coils of an air conditioning system so that it can remove heat from indoor spaces. While compressors are found in other appliances, air conditioning systems almost always use a hermetic compressor. What is a hermetic compressor exactly, and why do air conditioning systems use them?

What Is a Hermetic Compressor?

A hermetic compressor is a type of refrigerant-pressurizing device that’s characterized by a closed design. Hermetic compressors and their corresponding motors are packaged together in a sealed – typically welded – unit. All compressors work by pressurizing refrigerant. As the refrigerant becomes more pressurized, it will convert to a hot gas, which allows it to release more heat.

Compressors can be classified according to their design. There are hermetic, semi-hermetic and open compressors. Hermetic compressors have an open design. Semi-hermetic compressors have a semi-open design that leverages removable bolts or fasteners. Open compressors, on the other hand, are completely open. Open compressors are installed separately from their corresponding motors.

Protection From Environmental Contaminants

Both residential and commercial air conditioning systems almost always use a hermetic compressor. One of the main benefits of hermetic compressors is protection from environmental contaminants.

Compressors are installed outdoors. In residential air conditioning systems, the compressor is typically installed near the side of the home. In commercial air conditioning systems, it may be installed near the side of the building or the roof. Regardless, compressors are installed outdoors where they are exposed to dirt, dust, pollen, insects, moisture and other forms of environmental contaminants.

Hermetic compressors feature a closed, sealed design. Therefore, they are protected from environmental contaminants. Contaminants from outside your home won’t enter your air conditioning system’s compressor if it’s a hermetic compressor.

Protection From Leaks

Hermetic compressors are better protected from leaks than other types of compressors. Like all compressors, hermetic compressors contain refrigerant. Refrigerant must flow through a compressor in order for the compressor to pressurize it.

If refrigerant leaks out of a compressor, it will leak out of the entire air conditioning system. And as the air conditioning system’s refrigerant levels drop, it will no longer be able to remove heat from indoor spaces. Fortunately, leaks are less likely to occur with hermetic compressors. Hermetic compressors have an air-tight housing that allows refrigerant to move through them without leaking out of any seals or crevices.