How Air Conditioning Works

After reading this simple explanation of how your central air conditioner works, you should have a better understanding of how we keep our cool during hot summer days. A basic knowledge of air conditioning technology can help you maintain your system, know when to call your HVAC service technician, and understand what the service technician is doing.

If you have an air conditioner, you probably already are well aware that the unit sits outside your house. It contains the compressor and condenser as well as a fan, and may look something like this Trane air conditioner:

Inside the house, an evaporator coil attaches to your furnace. This coil is usually in a casing.

The refrigerant circulates between these three components – compressor, condenser, and evaporator coil. Refrigerant is a pretty busy and hardworking compound! As it circulates, it moves between gas and liquid states as pressure changes are forced upon it, which makes the refrigerant gain and lose heat through the cycle.

As an aside, something to know about refrigerant is that Freon is a brand name for R-22, which is being phased out due to greenhouse effects. There are other coolants in use today which are more environmentally friendly. A future blog topic will explain how this affects your existing air conditioning system.

Let’s follow the refrigerant through one cycle. Refer to the graphic as you read.

First, the refrigerant enters the compressor as a warm gas containing heat that was removed from the house. The compressor squeezes the gas, compressing the molecules and causing it to become even hotter.

Next, the gas flows into the condenser, where it moves through coils in the condenser. The fan pulls air from outside and blows it onto the hot coils, which transfers the heat from the gas to the outside air. As heat is removed from the gas, it leaves the compressor as it expands and cools to a liquid.

Then the cooled, liquid refrigerant is pulled inside the house into the evaporator coils where physical and chemical magic cause it to cool further. The blower on the furnace passes household air over the cold coils, transferring the chill to air that will flow through your house via the ventilation ducts. As the refrigerant gains heat, it returns to a gaseous state. The warm gas flows back into the compressor to start the cycle again.

Bit by bit, each cycle lowers the temperature of the air in the house, until the desired temperature is reached.

I hope that this post gave you better understanding of how your central air conditioner works to keep you comfortable during warm weather. Stay tuned for a post that will help you know how keep your AC running efficiently all summer.

If you need an AC tune up or would like an estimate for installing an air conditioner, contact KJ Thomas Mechanical online or call 303-435-8141