To deal with the sultry summers of the Twin Cities metro area, an air conditioner needs attentive care. Knowing how an air conditioner works helps you provide that care and troubleshoot any problems that may occur.
The first thing to know is that an air conditioner doesn’t produce cool air, but rather removes heat from your home. A 
refrigerant fluid cycles through the system, absorbing heat indoors, flowing outdoors to release that heat, then flowing back indoors to absorb more heat.
Cooling Your Home’s Air
The “cold side” of your system includes the expansion valve, the indoor evaporator coil and the blower fan. The expansion valve receives high-pressure liquid refrigerant from the outdoor unit. It rapidly releases pressure on the refrigerant, causing it to cool. In addition, it regulates the amount of refrigerant that enters the evaporator coil.
The cold liquid refrigerant now flows into the evaporator coil and circulates through it. The blower fan moves air over the coil and the cold refrigerant absorbs heat from the air. When moisture in the air hits the cold coil, it turns into condensation and falls into the condensate drain. What remains is cool, dehumidified air that flows into your air ducts and out to your rooms.
Getting Rid of the Heat
As the refrigerant absorbs heat, it evaporates into a hot gas. This gas flows through copper tubing to the outdoor condenser unit, known as the “hot side” of the system. First the refrigerant enters the compressor, which pressurizes the gas. It then flows to the condenser coil. A fan blows air over the coil to help cool the refrigerant inside. This is where the refrigerant shakes off most of the heat it picked up in your house. The refrigerant leaves the condenser coil as a high-pressure liquid and flows back through copper tubing into your house. It enters the expansion valve to start the cooling cycle all over again.
For more help understanding how an air conditioner works or for repairs or maintenance, contact Marsh Heating & Air Conditioning in the Twin Cities metro area.
Our goal is to help educate our customers in Minneapolis-St. Paul, Minnesota about energy and home comfort issues (specific to HVAC systems). For more information about air conditioners and other HVAC topics, download our free Home Comfort Resource guide.
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