How an Air Conditioner works
Curious to know how your air conditioner works? It all starts with
the refrigeration cycle, but before we begin, there are a few things you
you need to understand.
- Heat is a form of energy. “Cold” is not a form of energy; it is simply the lack of heat.
- Heat always travels from hot to cold. The greater the temperature difference, the faster it travels.
- Liquids absorb heat when they boil off to a gas
- Gasses give off heat when they condense to a liquid.
- The temperature at which a liquid boils is controlled by its pressure. High pressure = high temperature; low pressure = low temperature.
Most people tend to think that air conditioners make cold air and the temperature at which they set their thermostat should be the temperature of the air that is coming out the supply vents. In fact, an air conditioner simply moves heat from one area to another. What is left behind is “cold”. The thermostat is simply a switch to turn on/off the unit when desired temperature is needed or met.
So how does my air conditioner remove heat energy?
Your air conditioner removes heat energy by means of the refrigeration cycle. All air conditioners have the same basic components . A Compressor, Condenser, Evaporator, and Metering Device. These four items are required to maintain the refrigeration cycle.
It all starts with the Compressor. The compressor “compresses” the refrigerant to a high temperature; high pressure superheated gas. The superheated gas then moves to the condenser where it “condenses” to a high pressure subcooled liquid. Remember, gasses give off heat when they condense to a liquid. So, the Condenser rejects heat.
The now subcooled liquid now makes it way to the evaporator, but before entering the evaporator the liquid refrigerant passes through a Metering Device. This device restricts the flow of refrigerant causing a drop in pressure. What passes through is now a low pressure; low temperature saturated mix of liquid and gas. This saturated mix travels through the evaporator and because of its low temperature (around 40 degrees F), heat energy from the home is absorbed through the coils turning the low temperature; low pressure saturated mix to a low temperature; low pressure superheated gas. The superheated gas then makes its way to the Compressor and the whole cycle starts over.
There are other components that aid in the refrigeration cycle, such as fans to push or pull air across the evaporator and condenser coils. These components are also very important in aiding your air conditioner in removing heat from your home.