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How Air Conditioning Works

If you have ever wondered how an AC system works, please read the information below for a quick overview of how an AC system works, as explained by the best AC repair company serving Fairfax and Manassas, VA—Virginia Heating and Air.

Basically, an air conditioner cools a home or building by removing heat from inside the structure and transferring it to another area. There, chemical refrigerants absorb the undesirable heat energy, after which they are pumped through a system of pipes to a coil that is located within the main air conditioning unit on the outside of the building. The fan is also located in this outside unit. It draws in outside air and passes it over the hot coil, transferring heat from the refrigerant to the outdoor air.

Basic Operations:

Most air conditioning systems have five mechanical components, which are:
  • A compressor
  • An expansion valve or metering device
  • An evaporator coil and blower
  • A chemical refrigerant

Most central air conditioning units utilize a split system. In other words, they consist of a "hot" side and a "cool" side. The hot side, or the condensing unit—which includes the condensing coil, the compressor, and the fan—is located outside the home or building. The cool side is situated inside the home or office building. This portion of the AC system is made up of an expansion valve and a cold coil, and it is usually part of the furnace or other type of heating system. As the air conditioner operates, the furnace pushes air through the cold evaporator coil, which brings down the air's temperature. Then, the air conditioner distributes this cooled air throughout the home or building via a system of air ducts. A window-mounted AC unit operates on the same principal, with the only difference being that both the hot side and the cold side are located within the same housing as one standalone unit.

The compressor is the center of an air conditioning system. A compressor is a type of pump, and it causes the refrigerant to flow through the AC unit. The compressor's job is to attract cool, low-pressure refrigerant in its gaseous state, and then by compressing this gas, increase its pressure and temperature. The AC then sends this hot gas to the condenser coil.

The condenser coil is composed of a series of pipes and a fan that sucks in outside air, drawing it over the coil. As the refrigerant passes through the condenser coil and the cooler outside air travels across the coil, the air absorbs heat from the refrigerant, which causes the refrigerant to condense from a gas to a liquid. The hot liquid then travels to the expansion valve.

The expansion valve is the control room of the system. By measuring the temperature of the evaporator, or coil, it lets liquid pass through a very small hole, which causes the refrigerant to expand to a low-temperature gas. This low-temperature refrigerant flows to the evaporator.

The evaporator coil is a series of pipes connected to a furnace or air handler that blows indoor air across it, causing the coil to absorb heat from the air. The cooled air is then delivered to the house through a series of air ducts. The refrigerant then flows back to the compressor, where the cycle begins again.

Virginia Heating and Air services air conditioners for residents in Manassas and Fairfax, VA. If you have any questions regarding how your air conditioner works, or if your air conditioner requires service, repairs, maintenance, or needs to be replaced completely, please give us a call.