How Air Conditioning Works: 11 Key Things You Should Know

Have you ever thought to yourself “how do air conditioners work?” Well, you’re not the only one. So today I’ll tell you the eleven things you need to know about how an air conditioner works. Whether you’re a new homeowner, or you’ve been in your home for years, the more you understand about how an air conditioner works the better off you’ll be. We’ve broken your air conditioning down into three main parts: the outdoor unit also known as the condensing unit, the indoor unit (the furnace if it is a gas system, or the air handler if its electric heat or a heat pump) and the living space. Even though looks and styles differ between brands and models, this is more or less how your system will look and basically how an air conditioner works to cool your home. 

This is in no way meant to be a comprehensive technical guide to go over all the ins and outs and intricate components of how your air conditioner system works but rather an easy to understand guide for the average person. Now at the outdoor unit you have the fan, condenser coil, compressor, and refrigerant. The indoor unit has a blower motor, evaporator coils, a circuit board and the filter. In the living space you’ll find the thermostat, supply vents and return air vents. So how do air conditioners work? Well there’s a lot of moving parts and pieces, even more than we’ve got time to explain but they all have to be working together in order to get cool air in your home. 

It all starts when the temperature in the room rises, the thermostat sends a signal to the circuit board calling for cold air, the circuit board then turns on the blower motor in the house while turning the compressor and fan on outside, the compressor acts like a pump sending the refrigerant back and forth from the outside condensing coil to the evaporator coils inside, back and forth, back and forth, each time helping to remove warm moist air from the house. Meanwhile air is circulating in the house. The hot air in the room is drawn through the return air vents and blown across the evaporator coils, pay attention because here’s an important step in how an air conditioner works, cold refrigerant is being pumped through lots of little tubes woven through the evaporator coils, remember that compressor outside? As hot air from the house is blown across the evaporator coils the heat and moisture are removed and what you’re left with is cold air. The cold air is blown through the ductwork that runs throughout the house and comes out the supply vents, the air warms up and is drawn back in through the return air vents and the process is repeated until the room is cold enough that the thermostat sends a signal to stop, at least until the room heats up again, and that’s how an air conditioner works.

 Now these eleven things are designed to work together and if even one of them stops working you could experience a variety of problems the end result usually being no cold air and nobody wants that in the middle of summer. To avoid unexpected breakdowns there’s some simple maintenance you can do on your own to keep your air conditioner running as smoothly as possible all summer long. We will discuss maintenance in a future post. 

For more info on residential HVAC check out our video on residential split systems here: https://youtu.be/gM18vFd2I6o