The HVAC system is complex, with numerous parts working together to deliver hot and cool air and properly ventilate a home. Understanding how the HVAC system is built can help homeowners understand the common causes of breakdowns and keep their system maintained year-round. Here are a few important components of an HVAC system every homeowner should be familiar with.
The thermostat controls the temperature of the home and is located in an area with average temperatures. Homes with multiple thermally controlled zones may have more than one thermostat.
The heat generator uses hot flue gases to create heat. The heat generator may be a furnace, heat pump, or run on electricity.
The heat exchanger is a set of metal tubes or coils that connects to the burner assembly and ends at the vent or flue pipe. This key HVAC component separates air and gas to prevent mixing and exposure to harmful combustion byproducts, such as carbon monoxide.
The HVAC blower motor sends air from the furnace, heat pump, or air conditioner into the home through the duct system and out the vents. A blower motor can be single speed or variable speed. A single-speed motor starts up when a thermostat indicates the home needs more heating or cooling and shuts down once the home reaches the desired temperature.
A variable speed blower motor, also known as an electronically commutated motor, runs at lower speeds to maintain air circulation and air quality and uses less energy than a single-speed motor.
Condenser Coil or Compressor
The compressor increases the pressure of the refrigerant and sends it down to the condenser coils. The condenser coil rejects the heat coming from the compressor and cools down the refrigerant gas into a liquid form. Central (or split) AC systems have the condenser and compressor located outside of the home.
The evaporator coil absorbs heat from the air in the home and holds the chilled refrigerant that the compressor moves into it. As the air from the blower fan moves through the evaporator coil, the cold refrigerant eliminates heat from the home’s air. As the refrigerant heats up, it travels to the condenser coil.
Air Ducts and Vents
The ductwork moves air throughout the home and out the vents. Ducts may contain numerous air filters designed to eliminate air contaminants and pollutants.