Home HVAC System

Heating, Ventilation, and Air-Conditioning (H.V.A.C.) is a climate control system. Described here is the HVAC system for home or small office. This type of system is known as A Split, Forced Air Heating and Air Conditioning System.

Older systems heated the air and passively allowed air to circulate. Modern heating and cooling systems actively circulate the air with blower fans.

Air Conditioning (Cooling)

The same motor, blower, and duct work used for heating are used to distribute cool air from the air conditioner in a forced air system. The two main components of this system is the condenser (outside) and the evap­orator (inside, also called a-coil).

HVAC System Basic Components

INSIDE

Evaporator Coil (A-Coil)

A network of tubes filled with refrigerant. The colder than air tubes cause the removal of heat and moisture from the air as the refrigerant evaporates into a gas again.

Blower

Part of the Air Handling Unit. Forces air though the HVAC system (across the heat exchanger for heater application or across the a-coil for air cooling application.)

Heat Exchanger

The heat exchanger uses metal fins to help transfer heat from the area where it is produced by burning fuel to the air that flows through the duct work.

Plenum

The supply air plenum is usually on the top of the furnace on a traditional home HVAC system. The term may be applied specifically to the air box above the a-coil where the conditioned air enters from the HVAC before passing through and out the rest of the duct work. However, a plenum may be any contained space for air moving in or out of the HVAC duct work system.

OUTSIDE

Condenser Coil

A network of tubes filled with refrigerant that remove heat from the heated gas refrigerant and convert the refrigerant into a liquid form again. The excess heat escapes into the outside air.

Compressor

The pump that circulates the refrigerant in a closed loop between the condenser and evaporator coils. The compressor is the heart of the system; it keeps the refrigerant flowing through the system at specific rates of flow, and at specific pressures.