How Does Central Air Conditioning Work?

June 7, 2021
Central AC System in Boling-Iago, TX

Many of us are familiar with the term “centralized air conditioning system.” In fact, most of us have one in our homes. However, many of us don’t quite understand how an air conditioner works. Rather, we just set the thermostat to the temperature that we want and enjoy the outcome of the process.

Understanding Heat Transfer

The majority of people that are asked to explain how an air conditioner works will state that the air conditioner cools the air in their home. While that is the overall effect of the entire air conditioning process, that’s not really an accurate description of how it works.

The air conditioning process is actually a heat transfer process. The system inside of your home is designed to take the heat from inside your home and transfer it outside. In reality, this whole process is conditioning the heat from the air inside of your home.

Setting Your Thermostat

Every air conditioning system has a thermostat that controls when the system operates and when it shuts off. A typical thermostat will display the actual temperature inside of your home. It will also display the desired temperature that you can set. For example, your thermostat may read an actual temperature of 80 degrees and a desired temperature of 78 degrees.

When the actual temperature reaches above what your desired temperature is on your thermostat, your air conditioning system will kick on. This is because the thermostat signals to the remaining components that it’s time to cool the house. It will continue to run to cool the house until it reaches the desired temperature that you have set.

Pull Hot Air In

When your air conditioning system turns on, it starts the air handler. This is a big fan that works to pull air in through the return venting inside of your home. It pulls the air through the air filter, which helps to filter out any airborne pollutants like dust and debris. If you opted for having an air purifier installed in your ductwork, the air would also flow through the air purifier.

Transfer the Heat Out

Once the air goes through your air filter and potentially your air purifier, it is directed over the evaporator coil. As it passes the evaporator coil, the heat out of the air is transferred to the refrigerant that is found inside the coil. The refrigerant turns from a liquid form to a gaseous form when it bonds with the heat from the air.

As this process takes place, some of the humidity is lost out of the air. This excess moisture drips down off of the evaporator coils and into the drain pan. By removing some of the moisture from the air, it helps to make it feel even colder. The now cold air is forced back through the supply ductwork and is released through the supply vents throughout your home.

Releasing the Heat Outdoors

In order to keep supplying the evaporator coil with fresh refrigerant, the heat transfer to the refrigerant needs to be released. This is done in the outside compressor unit, which you can find against one of the exterior walls of your home.

The refrigerant is piped for copper tubing to the outside unit, where it enters a condenser coil. Inside the outside unit, there is a fan that blows fresh air over the condenser coil. This fresh air adheres to the heat inside of the refrigerant.

When the refrigerant loses its heat, it turns back into a liquid form. The now-heated air is forced into the outdoor air via the fan in the outdoor unit. The condenser coil works in a reverse fashion as compared to the evaporator coil. However, during both processes, heat is transferred from one substance to another.

Starting All Over Again

Once the refrigerant loses its heat and turns back into a liquid form, it needs to make its way back into the interior evaporator coil. It does this via copper tubing that runs from the outside unit to the inside unit. Before the refrigerant meets the evaporator coil, it must go through an expansion valve.

This expansion valve helps to alter the pressure in the refrigerant so that it’s ready to absorb heat once again. The valve also regulates the amount of refrigerant that can enter the evaporator coil at one time. This helps to ensure that the system continues to work effectively.

Once the refrigerant makes its way back into the evaporator coil, the cooling process starts all over again. This is a continuous process that runs until your home’s thermostat reads that your indoor air temperature matches your desire temperature.

Reliable AC Service

When you need assistance with your air conditioning unit, it’s time to call Hunter's Air & Heat, Inc.. We provide high-quality and reliable cooling, heating, duct cleaning, attic insulation, metal fabrication, and indoor air quality services to customers throughout the entire Boling area. Simply pick up the phone and give us a call today to get the home services that you need.

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