HVAC System Components

HVAC System Components

• The furnace, of course, plays a major role in home heating, unless your home uses a heat pump, boiler system, radiant heating, solar heating or another alternative system. You’ll probably find the furnace in the basement, attic, laundry/utility room or a closet. The furnace’s function is to provide and circulate warm air, or if it’s connected to your A/C, to distribute cool air, in both cases via ducts and vents.
• The heat exchanger, found inside the furnace, is where the air is heated. A fan pulls the outside air into the furnace, across the burners and into the heat exchanger. This is where the air is heated before being pushed out into the duct system.
• The evaporator coil, attached to the furnace, or else part of a dedicated air handler, contains refrigerant that removes heat energy from the air as it turns from a liquid into a gas. The remove of heat from the air creates cooling, and that cool air is distributed to the ducts and vents with a blower fan, either in the furnace or air handler.
• In central A/C and heat pump split systems the condenser/compressor is located outside the house in a metal box. It contains a condensing coil, compressor and fan. This is where the refrigerant gas is compressed and turned back into a liquid before being pumped back into the house. During this process, heat energy that was removed from the air inside the house is expelled into the outside air, as part of the cooling process. In a heat pump system, heat is absorbed from the outside air and transferred inside for home heating.
• The thermostat controls your cooling and heating equipment. Once the thermostat is set to a temperature, it will run your heating or cooling system to maintain that temperature in your home.
• Duct run through the walls, ceiling and floors in a house, distributing air to the rooms through vents and registers. Supply ducts and vents deliver conditioned air, and return ducts and vents return the spent air back to the furnace or air handler. Before entering the HVAC equipment again, the air is filtered to protect system components and improve indoor air quality.