Temperatures are heating up again; an air conditioner is something most of us take for granted, but most people don’t really know how it works.  Believe it or not, an air conditioner doesn’t actually cool the air.  Instead, it uses a process called heat transfer to remove the heat from the air.

In a nutshell, your air conditioner uses liquids called refrigerants that convert to gas at relatively low temperatures and absorb heat. The refrigerant is held within a closed system of coils and is forced to evaporate into gas and then condense into liquid over and over again in a continuous cycle.  The coils are cooled, and warm air from your home’s interior is moved over them and cooled by them.

This cooling magic takes place in your air conditioner’s three parts: compressor, condenser, and evaporator.

  • Compressor: Located outside your home, the compressor receives cool gas refrigerant and squeezes it in order to raise its temperature and pressure.  The refrigerant is now a hot, high-pressure gas.
  • Condenser: Also located outside your home, the condenser receives the heated, pressurized gas from the compressor. The condenser helps the heat from the gas to dissipate. The gas is now cooler and is a liquid. The pressurized liquid then goes to the evaporator in a very tiny opening.
  • Evaporator: The only part that is inside the house, and is often part of your furnace. Here, the pressurized liquid from the condenser cools and evaporates into a gas. This evaporation draws the heat out of the air surrounding the evaporator, making the air feel cooler. Now the cool, low-pressure gas returns to the compressor to start all over again.

The evaporator is connected to a fan, and connected to the fan is a system of vents and ducts, all working together to move the cool air inside the house.  The whole system is connected to your thermostat, which senses room temperature and activates the air conditioner until the room reaches the desired temperature.  The process is a cycle; the gas changes to liquid, the liquid changes to gas.  Warm air is constantly exchanged for cool air, giving you the feeling of comfort that can’t be beat on the hottest summer days.