How does an air conditioner work anyway?

What does an air conditioner actually do anyway? As HVAC people, our friends and family ask us this question all the time. We're busy checking out your A/C and talking to you about heating & cooling, so we wrote a blog post about it instead. If you’re reading this, it’s for you too.

So how does your a/c work?

You air conditioner works on a refrigeration cycle, combining air with other elements to move cool air in while cycling hot air out. The refrigeration cycle in an air conditioner involves four main components: the evaporator, compressor, condenser, and expansion valve.

1. Evaporator: This component is located inside the indoor unit of the air conditioner. It contains refrigerant in its liquid form. Refrigerant is a chemical compound that can easily change between liquid and gas states – remember this as it’s key to the whole process. The evaporator absorbs heat from the indoor air, causing the refrigerant to evaporate and turn into a low-pressure, low-temperature gas.

2. Compressor: The gaseous refrigerant from the evaporator is then drawn into the compressor, which is located in the outdoor unit of the air conditioner. The compressor compresses the refrigerant gas, increasing its temperature and pressure.

3. Condenser: The high-pressure, high-temperature gas from the compressor is then passed to the condenser coils, also located in the outdoor unit. Here, the refrigerant releases heat to the outside air and condenses back into a high-pressure liquid.

4. Expansion Valve & Metering device: The high-pressure liquid refrigerant then passes through the expansion valve or piston, which regulates the flow of refrigerant into the evaporator. As the refrigerant enters the evaporator, it expands and evaporates again, absorbing heat from the indoor air and completing the cycle.

This continuous cycle of absorbing heat from inside the room, releasing it outside, and then cooling the indoor air is how an air conditioner works to keep your space cool and comfortable.

And that’s how your air conditioner works, how my A/C works, and how Uncle Ben’s A/C works. But if your A/C isn’t working, or you’ve got other questions about the air in your home, give Compass a call.