How Does Air Conditioning Work?
An air conditioner is a standard appliance in interior comfort. The Energy Information Administration reports that 87 percent of homes have an AC unit and they account for almost 20 percent of yearly electricity consumption in the US. At Airheads HVAC, we believe that knowledge is power – the more you know about the appliances you are using, the more effectively you can operate them.
The modern air conditioner was invented in 1902 by Willis Havilard Carrier. It was invented to solve the humidity problem at a printing plant in Brooklyn. The concept of using chilled water to cool down certain areas predates his invention by centuries, however it is Carrier who is credited with inventing a system of chilled coils to maintain a constant temperature.
There are four main components of your air conditioner:
- Evaporator – receives the liquid refrigerant
- Condenser – facilitates the heat transfer
- Expansion valve – regulates the flow of refrigerant into the evaporator
- Compressor – pump that pressurizes the refrigerant
The refrigeration cycle inside your AC unit is as follows. It starts as a liquid and then goes through phase conversion to gas. Through this conversion it absorbs heat. It is then compressed and pushed through another phase transition back to liquid. Refrigerant is a chemical that allows this phase conversion to occur at low temperatures and it is this conversion cycle that creates what we know as modern air conditioning. The appliance forces this conversion to occur over and over again within a closed coil system.
Fans inside the unit blow warm air over the evaporator. The refrigerant inside picks up the temperature of the air. As it absorbs the heat from the air it turns into a vapor. The refrigerant goes from being a cold liquid to a hot vapor. The unit blows the cool air out while the hot refrigerant vapor passes into the compressor and gets compressed to an even higher pressure and temp. This then flows over the condenser which turns it back to a liquid and the heat is radiated away. Basically, the heat from the air is absorbed by the refrigerant and carried through the AC system to be pushed out the other side, while the cooled air is pushed inside.
An air conditioner also works as a humidifier and dehumidifier. You may have a moisture collection pan on your unit. As the refrigerant absorbs heat it also absorbs the moisture from the air.