Central Air Conditioning: How It Works

Whether it is the chilly air of the winter months or the relentless heat of the summer, we all rely on our central air conditioning to keep our homes comfortable. As you might expect, your friends at Spencer Air Conditioning and Heating want your HVAC system to run smoothly and efficiently all year long, but do you know how your central air conditioning works? An air conditioner is very similar to another appliance in your home — the refrigerator. Air conditioners don’t have the exterior housing a refrigerator relies on to insulate its cold box. Instead, the walls in your home keep cold air in and hot air out. The biggest job an air conditioner has to do is to cool the indoor air. That’s not all it does, though. Air conditioners monitor and regulate the air temperature via a thermostat and have an onboard filter that removes airborne particulates from the circulating air. Air conditioners also function as dehumidifiers because temperature is a key component of relative humidity, reducing the temperature of a volume of humid air causes it to release a portion of its moisture. That’s why there are drains and moisture-collecting pans near or attached to air conditioners and why air conditioners discharge water when they operate on humid days. The major parts of an air conditioner manage refrigerant and move air in two directions: indoors and outside: • Evaporator – Receives the liquid refrigerant • Condenser – Facilitates heat transfer • Expansion valve – regulates refrigerant flow into the evaporator • Compressor – A pump that pressurizes refrigerant The cold side of an air conditioner contains the evaporator and a fan that blows air over the chilled coils and into the room. The hot side contains the compressor, condenser and another fan to vent hot air coming off the compressed refrigerant to the outdoors. In between the two sets of coils there’s an expansion valve. It regulates the amount of compressed liquid refrigerant moving into the evaporator. Once in the evaporator, the refrigerant experiences a pressure drop, expands and changes back into a gas. The compressor is actually a large electric pump that pressurizes the refrigerant gas as part of the process of turning it back into a liquid. There are some additional sensors, timers and valves, but the evaporator, compressor, condenser and expansion valve are the main components of an air conditioner. We hope this week’s blog has helped paint a picture of the basics of how your air conditioning system keeps your home comfortable. Your friends at Spencer Air Conditioning are here and ready to answer your questions or help with your air conditioning problems. Give us a call today at (972) 446-COOL (2665) or find out more at