Central Air Conditioning Basics

Family at table.

There are 4 major components to your Air Conditioner:


This is the first stop in the Air Conditioning cycle, and is located inside your outdoor unit.

The compressor is responsible for taking low temperature, low pressure gas and pumping out high temperature, high pressure gas to the condenser.


This is the outdoor casing to your A/C. As the refrigerant leaves the compressor a hot high temperature gas it enters the condenser coil.

As the refrigerant travels through the condenser heat is removed and the refrigerant is eventually condensed into a high temperature high pressure liquid. The condenser is vital to the cooling process, this is why it is important to keep your condenser squeaky clean.

Expansion Valve

The expansion valve regulates the amount of refrigerant entering the evaporator coil, and is located inside your home.

The expansion valve is typically a piston or a TXV, and responsible for taking a the high pressure hot liquid and releasing it as a low pressure, low temperature gas into the evaporator.  

Evaporator Coil

The last stop of the A/C cycle, the evaporator coil is located inside your home either on top of your furnace or underneath (depending on the setup of your furnace).

The evaporator’s function is to remove the heat from your home. Air is circulated over the coil containing low temperature, low pressure liquid refrigerant. As the air circulates over the coil the warm air is absorbed resulting in the cooling effect felt throughout the home.

Common Problems with your AC

One of the most common air conditioning problems is a dirty condenser. It may surprise how much cottonwood build-up can affect your home’s A/C performance. This is why vital to have your A/C cleaned or at least do it yourself and rinse down the coil. Interested in DIY, here’s how you can clean your coil.

Another frequently seen problem is improper airflow. Improper airflow can have an array of causes, but the most of the time it’s a dirty filter. Dirty filters block airflow and suffocate your HVAC system which leads to breakdowns, so change your filter!

The last and more difficult problem to identify is a clogged condensate drain. With a clogged drain the water produced by your A/C will have to go somewhere, usually into your furnace or onto your floors creating unwanted damage.

If you think your HVAC system has one of these problems it is best to have a certified HVAC technician come check it out for you, as you may have a bigger problem than you think. Our technicians will identify your problems and offer the right solution for your situation.  

For all of your air conditioning and HVAC needs call Chris Mechanical Services Inc.

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Call us at 630-206-5093!

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