Understanding the Main Components of Your Air Conditioner

Anatomy of an air conditioner

When things go awry with your air conditioner, it can be difficult to understand the technical lingo your HVAC technician might use when diagnosing the issues. Knowing exactly how it works will make you a better-informed consumer when you need to repair a part on your unit or replace it entirely.

There are many different components in a central air conditioner that work together to cool down your home. Similar to how your refrigerator works to keep your food cool, your air conditioner contains different mechanical components to keep you cool indoors. Not all of these parts are found in every type of air conditioner unit, however. They are found in most central air conditioner units, which is the most commonly used air conditioner type in the U.S.


Refrigerant is one of the most vital parts of your air conditioner. Without it, there is no way for your air conditioning unit to properly function. When combined with the other parts of your unit, this fluid can absorb heat and humidity from your home, replacing it with cool air.

In most units, the refrigerant cycles between a gas and a liquid depending on what phase of the air conditioning cycle it’s in. There are two main types of refrigerant used in air conditioning units, including R-22 and R-410A. Because of its harmful effects on the ozone, R-22 is being phased out and will be gone completely by 2020. That means that if your air conditioner uses R-22, you will probably need to update it the next time anything goes wrong with your unit. R-410A is considered safer for the environment by the EPA because there is no chlorine in the refrigerant, and it doesn’t harm the ozone as much as R-22. Air conditioners that run using R-410A tend to be more efficient, as well.

Below is the cycle your refrigerant follows within your central air conditioner unit.

1.      Compressor

Located in the outdoor portion of your unit, the compressor is basically the motor to your air conditioning unit. It works to change the refrigerant from a liquid to a gas so that it can be circulated through the outdoor part of the unit. It starts by pulling in the cooled refrigerant gas from the evaporator coil which is located indoors. The compressor then squeezes the refrigerant, heating it up into a high-pressure gas, which is important for the next step as it pushes the hot refrigerant gas to the condenser.

2.      Condenser

Once the hot refrigerant gas has exited the compressor, it enters the condenser, which is a series of coils inside the outdoor part of your unit. As the refrigerant is moving through the condenser, cool air passes over the coils, removing most of the heat from the refrigerant. As the refrigerant exits the condenser, it is in a warm liquid state rather than the hot gaseous state it was when it entered.

3.      Expansion valve

The refrigerant then enters the expansion valve, where the refrigerant changes state from liquid back to gas. As the refrigerant changes into a gas, all the heat that was contained in its liquid state is released. The refrigerant is at its coolest temperature after leaving the expansion valve.

4.      Evaporator coil

The compressor moves the chilled refrigerant into the evaporator coil, which functions to remove heat from the surrounding air and pump the cooler air into your home with the help of a blower. This component is typically found in the mechanics installed in your home. As warm air is blown onto the evaporator coil from inside your home, the refrigerant absorbs the heat, thereby cooling the surrounding air which is blown back into your home. The refrigerant, which at this point is back to a cooled gaseous state, is drawn back into the compressor to begin the process over again.

5.      Fan

With so much overheated refrigerant running through it, the outdoor condensing unit becomes very hot. To prevent the unit from overheating, the final step is the fan blows the accumulated heat out of the unit into the air outside.

Below are additional components of your air conditioning unit that help it run properly.


Because the air conditioning unit must continuously pull air from the outside to cool and pump into your home, you might expect dust and allergens to enter your home. However, a clean air filter functions to sift the air coming into your home to keep particles from being released with the cool air.

Depending on the type of unit you have, you may have an air filter attached to your outdoor air conditioning unit or, in the case you have a forced air system, you may just have a filter covering an indoor vent. If you have a permanent filter, you can simply clean it with water and a vacuum cleaner. If you have a disposable filter, make sure you’re replacing it every month if you have outdoor allergies or pets, and, if you don’t have allergies or pets, every at least once every three months depending on the type and quality of your air filter. Replacing your air filter will improve the efficiency of your air conditioner and keep you breathing fresh, clean air!


A thermostat serves as the control center of the entire air conditioning process. Think of it as mission command. A thermostat reads the current temperature of the room and uses these readings to tell the air conditioner when to turn on and off. Programmable thermostats take things one step further and can set temperatures depending on the time of day. Wi-Fi enabled “smart” thermostats provide the most precision of all, and actually “learn” from your usage patterns to adjust the temperature with no input from you.

How Chas Roberts can help

When functioning properly, these parts seamlessly work together to keep you and your home cool. However, sometimes one or more of these components can malfunction, which can stop the entire process and interrupt your life.

The expert technicians at Chas Roberts have seen it all in our 75 years serving Arizona and understand how detrimental a malfunctioning air conditioner can be, especially during the hot summer months. If your air conditioner isn’t working correctly or you suspect it’s running inefficiently, contact us today so one of our experienced HVAC technicians can diagnose the problem and have your system back up and running in no time!