For many people, the science of air conditioning is an enduring mystery. Why should you worry about understanding it? If your A/C keeps your home cool in the summer, what more can you ask? As a matter of fact, knowing how an A/C works, particularly the refrigeration cycle, can help you troubleshoot problems that may arise, as well as perform limited maintenance tasks.
The Refrigeration Cycle
First, let’s talk about the refrigerant that’s essential to air conditioning. The old standard refrigerant was R-22, popularly known by its brand name, Freon. R-22 has been undergoing a phase-out for environmental reasons, and other refrigerant solutions have largely taken over, including R-410A, or Puron. Refrigerants evaporate at very low temperatures. For R-410A, that’s 55 degrees below zero. When refrigerant boils, it absorbs heat from the surrounding air. Conversely, when refrigerant is put under high pressure, it will convert back into a chilled liquid.
An air conditioner exploits these unique conversion qualities by pumping refrigerant through two coils. In a split-system A/C, the evaporator coil is located indoors, and the condenser coil is located in the outside unit. When refrigerant moves through the evaporator coil, an expansion valve eases the pressure, allowing it to boil. When this happens, the refrigerant absorbs heat from the surrounding air. The subtraction of heat energy and moisture cools and dehumidifies indoor air.
At this point, the refrigerant — now a gas — is pumped to the outside unit by a compressor that pressurizes it, turning the refrigerant back into a liquid. The heat that was removed from inside the house is released into the warm outside air, and the process starts over again. In the inside and outside units, a fan blows air across the coils to accomplish the heat exchange. Inside the house, a fan also distributes the cool air throughout the house through your ductwork.
To learn more about the refrigeration cycle of your air conditioner or to discuss installing a high-efficiency air conditioning system in your Twin Cities home, contact us at Marsh Heating & Air Conditioning.
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 A/Cs and other HVAC topics, download our free Home Comfort Resource guide.
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