Heat exchangers are vital parts of HVAC systems. They contribute to the conservation of energy and the overall reduction of energy bills.  But what exactly is a heat exchanger? A heat exchanger is a type of equipment that transmits thermal energy from one medium or location to another. Heat exchangers do not only help with the cooling and heating your home or other buildings. They also help your HVAC system work much more efficiently. Condensers, evaporators and earth coils are examples of the kinds of heat exchangers that are found in HVAC units.  In order to better understand how heat exchangers work, below are the parts of devices in two of the most common kinds of HVAC equipment:

How Air Conditioners Use A Heat Exchanger

Air conditioners eliminate heat from indoor areas and transfer it outside. It uses refrigerant and relies on it to complete this process. The refrigerant transmits, absorbs and releases heat. It changes it from gas to liquid, and back again during the process of refrigeration. Below are the various steps:

  1. The refrigerant passes through various components in the air conditioner. It moves the heat as it goes through.
  2. The refrigerant begins as a low-pressure liquid inside the evaporator coils.
  3. A fan blows the warm air in an inside space across the coils. And then, the refrigerant is changed into gas as it absorbs the warmth from the air. This in turn, cools the room.
  4. As it has now become a low-pressure warm gas, the refrigerant journeys into the compressor. The compressor is usually located outside. By this time, it is converted into a high-pressure, hot air.
  5. Then, the refrigerant travels into the condenser. The condenser is also usually found outside.
  6. As air drifts over the condenser, it moves away the heat from the refrigerant along with it. This causes the refrigerant to transform again into a high-pressure, cold fluid.
  7. The refrigerant will then cool off even further in the expansion valve prior to returning to the evaporator in order to absorb even more heat to transfer out of the building.

Although the entire air conditioning unit can be considered as the heat exchanger. The condenser really is the part that is in charge of heat transfer inside the air conditioner.

How Gas Furnaces Use Heat Exchangers

For many years, gas furnaces are considered as one of the most common appliances used to heat homes during the cold winter season. These units use heat exchangers to increase the temperature of the air before diffusing it all over a building through pipes, ducts or other channels.

An airtight vessel is considered as the heat exchanger in a gas furnace. It has a hole below, and it also has a hole at the top. This is called the flue. Below are the different steps a heat exchanger makes inside the gas furnace:

  1. Burners produce burning gases and transfer them through the first opening to the heat exchanger.
  2. Simultaneously, a blower passes indoor air through the outside of the heat exchanger.
  3. The heat exchanger then uses the combustion gases to heat the air. This in turn is scattered across the house.
  4. The combustion process produces exhaust gases. These gases are freed through the flue to the exterior of the house.

The heat exchanger in a gas furnace exchanges the heat from the combustion process to the air carried over it. It also keeps the toxic combustion vapors isolated from the warmed up air.

Heat Exchangers Help Keep Us Comfortable

Although exchangers are used in a different ways, they’re usually used in heating and cooling HVAC systems. A heat exchanger in an air conditioner eliminates heat from your home during the summer, and a heat exchanger in a furnace keeps you warm during the winter. With this, it is important to invest in HVAC maintenance and get your system checked. Harris Air Services offers Air Conditioning and Heating services including replacement, AC and Heater repair, and installation. They also have emergency maintenance services. When it comes to heating and cooling, they are among the best companies in residential service and replacement.