Fireplace Glossary of Terms

Bellows - a popular accessory to help boost combustion in wood fires, feeding air to the flames as it is forced out of an expandable bladder. Though unnecessary for a gas hearth where the combustion level is easily controlled with the turn of a knob, bellows' lovely finish in attractive blends of fine woods with vinyl or leather makes them a decorative accessory.

BTUs - British Thermal Unit, the primary heat measurement unit used by the hearth industry. It is the amount of heat required to raise the temperature of 1 lb. of water by 1 degree F.

Catalytic Combustor - a device used on some wood burning stoves to reduce the temperature at which smoke is ignited.

Clearance - the distance required by building and fire codes between stove, smoke pipe or chimney and combustible materials such as wood furniture or carpets. Clearances must be obeyed even if the combustible materials, such as wood furniture or carpets, are protected by noncombustible plaster or other masonry materials.

Creosote - a very flammable byproduct of combustion that can build up within the smoke pipe and chimney and then ignite, causing "chimney-fire."

Direct Vent Appliance - an appliance that draws combustion air from outdoors and exhaust it combustion products to the outdoors eliminating the need for a standard chimney system. A glass panel in direct vent units is critical to keeping the combustion system sealed from the home, maintaining high efficiency and indoor air quality.

Emissions - byproducts of combustion vented out of the home.

EPA Regulations - government regulations of wood burning appliances mandating that products sold after July 1, 1992, emit no more than 4.1 grams of particulate matter per hour for catalytic-equipped units and no more than 7.5 grams for non-catalytic-equipped units.

Firebacks - protect fireplace masonry and mortar, shielding them from extreme heat of the flames. Cast-iron firebacks store heat from the fire and radiate it into the room after the fire has died down. Firebacks work just as well in a modern gas fireplace as they do in a traditional wood burning one.

Fireplace Inserts - heating units that retrofit into an existing fireplace (masonry or factory-built). They burn wood, gas or wood pellets and offer superior efficiency.

Flue - vent or chimney for a combustion device.

Freestanding stove - a heating appliance normally on legs or a pedestal that occupies an area roughly equal to that of an easy chair.

Gas Logs - provide dramatic realism from the lifelike ceramic fiber, concrete or refractory logs down to the glowing embers. Manufactured log sets have a burner that uses either natural gas or propane.

Glass Doors - close off the opening of the hearth so heat from the central heating system does not escape up the chimney when the fireplace is not being used.

Grate - an iron frame used to hold burning fuel in a fireplace.

Hearth - traditionally refers to the floor of a fireplace on which a blaze is built. Today it is also used to refer to all the devices and equipment used in connection with the fireplace and the stove industry.

Heat Shield - a noncombustible protector used around appliances, smoke pipe or chimney.

Hopper - a container attached to an appliance in which fuel, either coal, nuggets or wood pellets, is stored and from which the fuel is fed to the burner.

Island Fireplace - a fireplace that has four sides of glass, for viewing from any angle.

Kindling - thin, dry wood used to start a fire.

Liquid Propane - liquefied petroleum gas, available in cylinders, for home use.

Mantle - an ornamental facing surrounding the fireplace or simply a shelf above a fireplace.

Metal Liner - used primarily with fireplace inserts and placed inside an existing chimney (usually masonry) to reduce the diameter of the flue for more rapid exit of smoke and combustion gases. Also used when an existing chimney is unlimited or deteriorating.

Natural draft (B-vent) Appliances - a gas-burning appliance that takes in combustion air from the home and vents products of combustion outside the home.

Natural Gas - clean-burning fossil fuel available in vast quantities throughout North America and delivered to homes via an extensive pipeline network.

Pellets - are made of 100% wood sawdust with no additives. The sawdust in pellets is a manufacturing byproduct otherwise destined for landfills.

Peninsula Fireplace - a fireplace that has three sides of glass.

Seasoned - refers to fuel wood that has been allowed to dry before burning. Seasoning generally takes six to 12 months. Wood burns much easier when its moisture content has been reduced. Freshly cut woods contains over 20% water.

Steamers - kettle-like steamers, available in a wide range of styles and colors, harness the heat energy of fireplaces and stoves and release warm moisturizing steam into the air.

Unvented or Vent-Free Appliance - an appliance that draws combustion air from inside the home. The appliance is designed to burn so efficiently that it eliminates the need for venting.

Vent-Free - gas appliance that has no need for a flue.

Zero-Clearance Fireplace - a factory-built fireplace that is constructed so that it can be placed, safely, close to combustible material.