You rely on your air conditioning system to keep you cool and comfortable all summer, but do you really understand what goes on under the surface that allows it to work? Air conditioning systems are fairly complex and contain a wide variety of components. One of the most important parts of a cooling system is the condenser. We’ll explore all you need to know about AC condensers and what role they play in keeping your home cool.

What’s an AC Condenser?

Most central air conditioners are split systems, which means part of the system is outside the house and the other part of it is located inside. In this type of system, the condenser is the outdoor part. An AC condenser consists of three main parts: the compressor, condenser coil, and fan. The indoor part of the system primarily consists of the evaporator coil and the blower, which is the term for the fan that circulates air through the ductwork. The indoor and outdoor parts of the system are then connected by a set of two copper lines that carry the refrigerant inside and then back outside. The final primary component is an expansion valve, which is located in between the condenser and the evaporator.

There are also packaged central air conditioning systems, which still have the same basic parts. The only difference in a packaged system is that all of the components are housed within a large compartment that sits outside. That means that both the evaporator and condenser are in the same place.

What Does an AC Condenser Do?

All air conditioning systems work based on the process of heat transfer and use a special refrigerant chemical to move heat from one location to another. This means that they capture and remove heat from the warm air inside the building so that the air gets cooled as it moves through the unit. The heat is then transported outside to the condenser, which releases the heat into the air outside.

Heat energy will always naturally move from a warmer area and be absorbed or flow out into a cooler area. This is what allows an AC unit to cool the air inside a home. The refrigerant that flows through the indoor part of the system — the evaporator coil — is much colder than the air inside the house.

The process begins with the compressor pumping cold liquid refrigerant inside to the evaporator coil. At the same time, the blower inside the house begins pulling warm air into the system via the return air vents and ductwork. When this warm air moves over the evaporator coil, much of the heat it contains flows out and is absorbed by the refrigerant. This results in the refrigerant changing from a cold liquid to a warm liquid as it moves through the evaporator coil. It eventually gets pumped back out to the condenser.

When the refrigerant enters the condenser unit, it moves through the compressor. Compressing the refrigerant greatly increases its pressure, which instantly causes it to boil and change from a warm liquid into an extremely hot gas. The hot gas then gets pumped into the condenser coil, which serves the opposite role of the evaporator coil. As the condenser fan blows air over the condenser coil, the heat stored in the refrigerant is naturally released and flows out into the air. This obviously results in the refrigerant cooling down again and changing back into a liquid.

At this point, the liquid refrigerant is still relatively warm since it can only continue releasing heat until it cools down to whatever the outdoor temperature is. To overcome this, the refrigerant first gets pumped through an expansion valve as it travels from the condenser back to the evaporator coil. The expansion valve serves the opposite role of the compressor. That means that it greatly decreases the pressure of the refrigerant, which instantly cools it so that it again changes back to a cold liquid.

This process works in a continual cycle with cold refrigerant flowing inside and hot refrigerant moving back outside. The thermostat inside the house is what controls the cooling process. It eventually signals the AC unit to shut off once it registers that the air in the home gets cooled down to whatever temperature you have your thermostat set at. Once the temperature in your house starts to rise again, the thermostat will signal the system to run, and the process will start all over again.

Common AC Condenser Problems and How to Spot Them

The condenser is considered the most important part of an AC system since the compressor inside it is what moves the refrigerant through the unit. As such, many of the most common AC issues are related to one of the components inside the condenser. If the compressor or condenser fan isn’t working properly, it will usually lead to either your AC unit not cooling nearly as quickly or starting to blow warm air. However, your air conditioner will also start blowing warm air if the evaporator coil freezes up, which is why you’ll need a professional inspection should this issue arise.

One thing to always watch for is if the condenser fan isn’t running when your AC unit is on. A malfunctioning, jammed, or broken condenser fan is a serious issue, and you should make sure to immediately shut off your air conditioner if you ever notice the fan isn’t running. For a cooling system to work properly, the condenser fan has to constantly pull air in and blow it over the condenser coil. If the fan doesn’t run, the system won’t be able to release heat outside and the refrigerant will remain at a much higher temperature and pressure. This puts lots of additional strain on the compressor since the higher pressure makes it harder for it to pump the refrigerant through the equipment.

The increased workload can then lead to the compressor motor overheating, causing your AC unit to automatically shut down. Even worse, it may cause the motor to seize up and burn out. A burnt-out compressor motor is the worst issue a cooling system can experience since it can’t be repaired and will need to be replaced. Unfortunately, replacing the compressor motor in your condenser will likely cost you about as much as just replacing the entire condenser unit.

Another thing to watch for is if your condenser starts making excessive noise or unusual sounds since this is a sure sign that it has some type of issue. A humming or buzzing sound often indicates either an electrical issue or a problem with the compressor motor. If you hear a squealing or screeching sound, it’s usually related to either the condenser fan or the bearings on the condenser fan motor or compressor motor.

One final thing to note is that the various components in the condenser need to be inspected and serviced regularly by a certified technician for your AC unit to continue working properly. Without proper maintenance, many issues can arise that lead to your air conditioner not working effectively and decreasing its energy efficiency. For instance, the condenser coil should be cleaned at least yearly since dirt and dust will prevent the refrigerant from being able to effectively release heat. Electrical issues like a frayed wire or loose connection could also cause the condenser to short circuit, which can lead to severe damage or even destroy the unit’s motors.

Since 1985, Cowboys Air Conditioning & Heating has been helping customers throughout the San Antonio area with all of their air conditioning and heating needs. We offer expert HVAC repair, maintenance, and installation services, so give us a call for all of your home comfort needs.

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