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Why the Compressor in Your AC Is Crucial

air-conditioners-on-slabsAll the components in your home’s AC are important. If one or more isn’t working correctly, it affects system performance.

  • A miscalibrated thermostat causes improper cooling.
  • A frozen evaporator coil reduces how much heat the AC can absorb.
  • A broken fan motor stops air circulation.

The compressor, however, has special importance. Think of it as the engine for the entire air conditioner. It consumes the most power, and if it doesn’t work, the air conditioner cannot do its job. Period. Plus, the compressor costs more to replace than other components, so a failed compressor is a Very Big Deal.

The Compressor’s Job

What does the compressor do? It’s right in the name … it compresses the warm liquid refrigerant flowing from the evaporator coil. When the refrigerant is compressed, its pressure increases and it turns it into a hot gas. This is the energy source in the air conditioner that allows it to cool down the house. The electricity going to the air conditioner mainly powers the compressor motor to charge the refrigerant and make it circulate. The circulating refrigerant releases heat to the outdoors along the condenser coil and absorbs heat from the indoors along the evaporator coil. This process is called heat, and it is what cools down your house.

Compressor Mechanics

The compressor works like a piston-driven car engine. A motor-driven crankshaft turns a series of pistons in chambers. As the pistons draw up, they pull in liquid refrigerant through a suction line. The crankshaft pushes down the pistons, compressing the refrigerant until it changes into a gas. The high pressure of the gas forces the refrigerant out another line and out of the compressor. It then flows toward the outdoor condenser coil to start heat exchange.

Compressor Failure

This picture of the compressor’s mechanics makes it easy to see how it can fail. The compressor requires oil lubrication to reduce mechanical friction, and the accumulation of wear over time forces the compressor to work harder. This is one of the reasons an air conditioner loses efficiency as it ages. A compressor may also hard start and need an extra jolt of electricity sent to its motor, which a technician can fix with a special hard-start kit.

Regular air conditioning maintenance can keep a compressor in excellent shape for years, sometimes more than 15. But the compressor will eventually fail if the air conditioner isn’t replaced—and a failed compressor usually forces an air conditioning replacement. Replacing only the compressor when your AC dies is an option if the unit is still under warranty. If it’s not, go over options with an HVAC professional. You’ll probably need a new outdoor condenser unit and indoor evaporator coil installed. You may also choose to have a new heating system and air handler installed at the same time if those parts are past their prime.

For excellent help with your air conditioning in Chicago, IL, call our technicians. We’re here day and night to fix or inspect cooling systems when they malfunction.

ServiceMax Is Open 24/7—All Day, Every Day! Reach out for repairs in Chicagoland.

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