April 6, 2021
Air Conditioner

Can you name two major parts of your air conditioner? If you are like most people, you may be able to get one but probably not more than two. Not being an HVAC professional, that is totally fine, at least until something in your system goes haywire.

Air conditioners are often forgotten members of your home until they stop working. When something does break, it consumes both your thoughts, time, and pocketbook. When you know a little about your system, you can trust that your repair technician is being honest.

Understanding How Your System Works

Before digging into the individual parts, it may be helpful to know the basics of how the system works. As you probably know, your system circulates refrigerant between the indoor unit and the outside unit. This refrigerant actually absorbs heat from inside your home and transfers it to the air outside.

To make the refrigerant work properly, your system has to control the pressure in the parts of the system. Pressure directly affects temperature. When pressure increases, so does the temperature. A drop in pressure results in a drop in temperature.

When the refrigerant gets outside, the pressure is increased to allow the heat to more effectively vent off. When it comes in, the pressure drops significantly to give it the cooling effect. Now that you understand this, let’s talk about the different parts.

Evaporator Coil

The evaporator coils are located inside your home, usually near an air handler or your furnace. This is the part that is cold and allows the air moving into your home to feel cool. What it actually does is allow the refrigerant to absorb the heat from your air as it moves over the coils.

These are notorious for collecting air contaminants not trapped by your air filter. The contaminants restrict airflow over the coils. To avoid this restriction, the coils should be cleaned annually during regular maintenance.

If you hear a screaming sound coming from them, turn your system off immediately. You may have a dangerous refrigerant leak, and you probably need to call a repair technician.

Circulating Fan

The circulating fan draws air into your HVAC system, pulls it over the evaporator coils, and then pushes it back out into your home. Like the evaporator coils, these commonly collect contaminants and need to be clean.

The fan also needs to be checked for proper balance to avoid excessive wear on the blower motor. If you hear a rattling, clanking, or banging, this may be the culprit. A screeching sound suggests the bearings in the motor need attention.


As the refrigerant travels outside, it will come to the compressor. This is the component that increases the pressure of the refrigerant, allowing it to transfer the heat to the air. Because of the job it performs, this part may go bad, requiring replacement and a system recharge.

Aside from general performance problems or an increase in energy bills, your outside unit may give you specific noises indicating a compressor problem. These are generally odd sounds that may sound like a growling, screeching or even a clattering. All of these sounds may be indicative of other problems too, so a professional diagnosis is recommended.

Condensing Coils and Fan

Once the refrigerant is properly pressurized, it goes into the condensing coils. This set of coils is much like the radiator in your car and allows heat to transfer to the air. To assist with the transfer, the condensing fan draws air in from around your unit and then vents it out of the top.

The condensing coils can collect debris and dirt from sitting outside and should be carefully cleaned regularly. If you hear a screaming sound from these, you may have a refrigerant leak and should shut down your system. Call for a professional diagnosis and repair if you suspect a refrigerant leak.

The fan motor is more likely to give you problems and may have similar symptoms to a bad circulating fan. If you hear a rattling sound coming from your condensing unit, it may simply be the blade mounting screws that need to be tightened. A technician will inspect all the components of your condensing unit during maintenance to ensure they are tight and working properly.

If you suspect your air conditioner is not working properly, get a professional diagnosis and have it repaired quickly. Leaving problems unchecked leads to larger problems and more extensive bills. Bash Heating & Air Conditioning, Inc. has provided air conditioning repair and maintenance to the Champaign residents since 1952. Our team also provides air conditioning installation and heating installation, repair, and maintenance services. Call to schedule your air conditioner repair or maintenance service today.

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