Air conditioners are life savers for most people in the hot summer months, but how exactly do they bring us the much needed cool air? There are 3 main components in every AC: compressor, condenser and an evaporator. These pivotal pieces of machinery all work together to create the chilly air we crave. Here’s how it works.

Generally air conditioners use chemicals that can be converted back and forth between a liquid and a gas. This process is used to take all of the hot air from a space and transfer it outside. This is where the compressor comes into play. The chemical goes into the compressor as a cold gas with low pressure. The compressor then squeezes it, forcing the molecules closer together. The more compact the molecules get, the higher the temperature becomes.

The next stop is its first trip to the evaporator. The hot air is circulated and changes from a gas to a liquid before being pushed into the cooling compartment. The air inside the compartment is passed through the evaporator’s metal fan where they then exchange thermal energy. This turns the liquid back into a gas once again while pulling all the heat out of the chemical.

Once the heat is removed from the chemical / air mixture, the cool air is blown into the house while the chemical, also known as refrigerant, stays. At this point the condenser changes the chemical into a liquid; by this time it is completely cooled down. After making a second trip through the evaporator it is back to its original form, a cold gas with low pressure. This process continues until the area has reached the desired temperature which is determined by the thermostat.

There are a couple different types of air conditioners that use these methods. First we have the old school ‘through the window or wall’ AC. The technical names for these are unitary systems. They are a little less high tech and don’t use ducts to direct air flow.

Split systems are the more commonly seen units throughout homes today. These come in two different types: central and mini split. Central systems have their heat exchanger placed within the central furnace / AC unit of a forced heating system. This allows for even distribution of hot or cool air throughout the residence.

Mini split systems supply cooled air to a single room, though they can be chained together to chill multiple rooms at once.