Glossary
Air Conditioning and Heating Terms
F
Filter (air)
A device that removes contaminants, by mechanical filtration, from the fresh air stream before the air enters the living space. Filters can be installed as part of a heating/cooling system through which air flows for the purpose of removing particulates before or after the air enters the mechanical components.
Fireplace Insert
A wood or gas burning heating appliance that fits into the opening or protrudes on to the hearth of a conventional fireplace.
Flue
The structure (in a residential heating appliance, industrial furnace, or power plant) into which combustion gases flow and are contained until they are emitted to the atmosphere.
Flue Gas
The gas resulting from the combustion of a fuel that is emitted to the flue.
Forced Air System or Furnace
HVAC term for a type of heating system in which heated air is blown by a fan through air channels or ducts to rooms.
Freon
A registered trademark for a cholorfluorocarbon (CFC) gas that is highly stable and that has been historically used as a refrigerant.
Fuel Efficiency
The ratio of heat produced by a fuel for doing work to the available heat in the fuel.
Fuel Oil
Any liquid petroleum product burned for the generation of heat in a furnace or firebox, or for the generation of power in an engine. Domestic (residential) heating fuels are classed as Nos. 1, 2, 3; Industrial fuels as Nos. 4, 5, and 6.
Fungi
Any of a group of parasitic lower plants that lack chlorophyll, including molds and mildews.
Furnace (Residential)
In HVAC a combustion heating appliance in which heat is captured from the burning of a fuel for distribution, comprised mainly of a combustion chamber and heat exchanger.
