The type of furnace used to heat a commercial or industrial facility may be different from the system used to heat a residential dwelling. Many types of units are available, though most are either powered by electric current, or burn gas, oil or wood to generate heat. If you need to purchase or repair a furnace, here are some important terms to know.
HVAC – An abbreviation of Heating, Ventilation and Air Conditioning, used by dealers and service people.
Hydronic Heating – An alternative to the traditional furnace, a hydronic heating system uses insulated tubing to run hot water from a boiler beneath the floor or along base board heaters to heat a home.
Heat Exchanger – The part of the furnace that transfers consumed fuel into heat, or from a boiler to water for hydronic heating.
Load – In the HVAC industry, load refers to the quantity of hot air necessary from the furnace or hot water tank to achieve the desired temperature in an interior space.
Plenum – The part of the heating system that distributes heat through ducts and vents into the various rooms of a home or business.
Multi-Poise – A type of furnace that can provide heat through four different air flow configurations – upflow, downflow and horizontal left and right.
Power Vented Furnace – A power vented furnace is necessary to heat a home without a chimney.
Carbon Monoxide Detector – A malfunctioning furnace can cause hazardous carbon monoxide to circulate through the vent system. A carbon monoxide detector monitors the level of carbon dioxide and sounds an alarm when it becomes a danger.
It's difficult to send hot air through a building without a furnace of some type. Mostly, the term is used to describe a residential heating system based off of a central furnace, but can also be a reference to a direct fire heater used for boiler purposes or to industrial equipment.
The term comes from the Latin word "fomax," meaning "oven." It's believed that the first furnace was made by the Indus Valley Civilization during the height of its maturity, around 2500-1900 BC, and was used to make ceramics. As time has progressed, these appliances have become significantly more sophisticated. Units that are installed in the home or commercial building use air, steam, or hot water as a source to send heat through the ducts. In the United States, natural gas is the most commonly used fuel for these systems, but oil, coal, and wood can also be used. On occasion you'll see a furnace run by electricity or propane.
Sometimes a unit runs too hot or too cool. When a furnace needs repairs or replacement, an HVAC contractor is called out to assess the situation. If smaller parts like the pump, filter, or condensate drain hose for excess water are broken, the contractor can often replace them to keep the unit going. If something larger like the boiler or the exhaust vent pipe in non efficiency systems, the HVAC person may consider the condition too severe and recommend replacement. These folks may be able to get you price deals from the manufacturer since they'll be able to purchase parts in bulk.