Topic: Furnace Selection

What is a Furnace?

A warm air furnace is a device that provides space heating by pushing warm air to conditioned space through ducts.

Do you have a furnace? If you have a warm air furnace you have registers, grilles, vents, or air outlets in the conditioned spaces. You have ducts attached to those registers we call branch ducts. The branch ducts connect to trunks. The trunks go back to plenums. Plenums attach to the furnace. Warm air fans usually have a flex connection to the plenum. The furnace has a fan and a heat adder. The heat adder is usually called a coil if heat is being added by electricity, refrigerant, hot water, or steam. The heat adder is usually called a heat exchanger if you are burning something inside of it, like natural gas, propane, oil, wood, or something similar. Warm Air furnaces will also have a filter and then return air ducts.

Your warm air system might have a humidifier, ultra violet treatment, and other air treatment systems. Warm air furnaces are also commonly paired with central air systems.