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What Are the Major Parts of an Air Conditioner?

When the weather starts getting warm in Franklin, you depend on your air conditioner to keep your home comfortable. However, when it stops working, do you know which parts could be causing the problem and what sort of repair may be required? Here are the major components of any air conditioning system and what you can expect if they are damaged.

Air Conditioning 101

First, it is helpful to understand the basics of how your air conditioner works. While there is cold air that comes from the vents, it actually transfers heat.

As the refrigerant runs through the system inside, it absorbs heat from the air and transfers that heat to the air outside. Once it does, it cools down dramatically in order to absorb more heat and continue the cycle.

To help with the transfer of heat, the unit works on a pressure system. When you increase pressure, you increase heat. Likewise, if you drop the pressure of the refrigerant, you drop the temperature. This pressure is regulated by the compressor outside and a small expansion valve inside.

Circulating Fan

The circulating fan is what makes the air flow through your system. It actually starts by drawing in air through the intake vent and through the air filters and evaporator coil. It then pushes the air back out into your house once it is cooled.

This particular fan runs with both your air conditioner and furnace, so it experiences a lot of wear. To keep it working properly, it should be serviced during regular maintenance visits. This includes cleaning it to eliminate residual air contaminants, lubricating the motor bearings, and balancing the fan wheel.

If the motor wears out, it can be switched out without having to replace the entire system. However, it is included when most furnace units are replaced.

Evaporator Coil

The evaporator coil is inside, usually near the air handler or furnace. This is the coil the refrigerant runs through once the pressure is dropped and the refrigerant is cooled. Like the circulating fan, this should be cleaned as part of regular maintenance.

The evaporator coil is relatively fragile, so cleaning must be done cautiously to avoid any damage. If something does happen to the evaporator coil, it likely means replacing it. While you can replace just the coil, there are many instances where you are better off upgrading the entire system. If your air conditioner was manufactured before 2010, then you may still have the old R22 refrigerant. This is no longer being produced and is becoming prohibitively expensive to service.


Outside your home is the condensing unit. The first component the refrigerant encounters is the compressor. This part increases the refrigerant’s pressure, making it easier to transfer the heat to the outside air.

The compressor can be damaged, especially if there is a small refrigerant leak and not enough in the system. Signs the compressor is bad are a lack of cold air, low airflow through the system, or growling or humming noises coming from your condensing unit.

If your compressor breaks down, you will have to replace it rather than try to repair it. This component can be replaced on its own or as part of a larger replacement project. Work with your installer to evaluate the condition of your appliance and determine what would be the most cost-effective in both the short and long term.

Condensing Coil and Fan

After the refrigerant is pressurized by the compressor, it moves into the condensing coils. It is from these coils that the heat is transferred to the outside air. The condensing fan draws outside air through the condensing coils and then vents it out through the top of the unit.

If the condensing coils are damaged, you are likely better off replacing at least the condensing unit, if not the entire AC system. The cost of replacing just the coils is relatively high due to the sheer amount of work it requires. Replacing a bundled part of the unit ends up being more cost-effective and saves you from immediate repairs.

Does your cooling system need some help? Dugan Air Heating and Cooling has provided air conditioners around Franklin with exceptional care for over 14 years. We also offer competitive AC replacement and installation, along with heating installation, maintenance, and repair. Give us a call to schedule air conditioner maintenance or repair today.



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