AFUE Annual Fuel Utilization Efficiency. An offical heat source measurement rating for fireplaces and wall heaters.

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. at sea level.

B-Vent
A gas-burning appliance that takes in combustion air from the home and vents products of combustion outside the home. B-Vent is also commonly known as natural vent.

Builder Series
Fireplaces specially designed for builders and contractors, featuring a beautiful blend of elegance, efficiency and economy

Cabinet
A fireplace cabinet is usually a wooden finishing option for direct vent or vent-free fireplaces which are installed on the floor of the room and vented through the wall. They encase the entire fireplace and can be made for walls or corners. They range from 13 to 28 inches deep.

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

Catalytic or Non-Catalytic
Catalytic wood stoves and fireplace inserts have ceramic honeycombed chambers coated with a metal catalyst (usually platinum or palladium) that works to increase the rate of combustion. The catalytic combustor burns away gases and particulates normally emitted into the air. Catalytic wood stoves allow people to burn wood at lower temperatures for longer periods of time. With Non-Catalytic wood stoves, combustion occurs in the firebox. These stoves are generally less expensive than catalytic wood stoves and require less maintenance.

Chase
A structure built around, and enclosing, portions of the chimney and in some cases, housing the appliance.

Chimney Cap
A vented cap placed on top of a chimney to prevent obstructions such as leaves and bird nests. A chimney cap can also protect the chimney top from gusts of wind that will interfere with the draft.

Circulating Firebox
Has louvers at the top and bottom so that a fan can be installed. Louvers cannot be covered.

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 observed even if noncombustible plaster or other masonry materials protect the combustible materials, such as wood furniture or carpets.

Creosote
A flammable by-product of combustion that condenses on the inside of chimneys increasing the risk of chimney fires.

Direct Vent
An appliance that draws combustion air from outdoors and exhausts it's 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.

Electronic Ignition
Requires electricity to start the unit either 110 volt or battery.

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.

Firebox
That portion of the solid fuel appliance where the fuel is located and where primary combustion occurs.
Hearth The floor of the firebox, most commonly used in reference to fireplaces. More generally, the foundation upon which fires for aesthetic and heating purposes are built. Differs from floor protection.

Gas Log
A manufactured log generally made from ceramic or concrete. The gas log contains the burner unit and is meant to simulate the look and feel of a genuine wooden log on fire.

Hearth
The floor of the fireplace where the fire is built. It can also include or refer to the portion of that floor that extends into the room.

High-Efficiency Wood-Burning Fireplace
EPA-approved fireplaces offering a balance of elegance and energy efficiency

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

Mantel (Flush Mantel)
Another finishing option for direct vent and ventless fireplaces. They can be wood, marble or stone. The mantels do not encase the entire fireplace, but frame it. Therefore they are only 1 3/4 to 2 1/2 inches deep. Mantels are used when the fireplace is installed inside the wall or on the outside wall of the house.

Manually Controlled
Control the height of the flame at the unit only.

Mid-Efficient,
Heat-Circulating, Wood-Burning Fireplace

ODS Oxygen Depletion Sensor
A safety device that activates the fire’s flame monitoring device in case excessive levels of CO² (deadly carbon monoxide), are detected. This would reduce the levels of oxygen, causing the pilot flame to become unstable and lift off the thermocouple tip. The fire then turns off automatically before the situation becomes dangerous.

Pellet Burning
Made of 100% wood sawdust with no additives. The sawdust in pellets is a manufacturing byproduct otherwise destined for landfills.

Pilot
A small, continuously burning flame that a gas appliance uses to ignite the main burner.

Radiant Fireboxes
Also known as flush face. The facing (Stone, Tile, Brick) can cover above and below the fireplace opening.

Remote Ready
Able to turn the unit on and off remotely via a wired or wireless remote. Remote is sold separately. The height of the flame cannot be adjusted remotely. Not recommended for vented gas logs.

Seasoned Wood
Fuel wood that has been allowed to dry for at least six months to a year before burning. Seasoned wood has lower moisture content which allows it to burn hotter, more efficiently, and with less smoke.

Surround
For this site we will define a fireplace surround as a marble or tile frame between the fireplace itself and the wooden mantel. Cabinets seldom use surrounds. However, some manufacturers do call a wooden cabinet a "cabinet surround".

Thermostatically Controlled
Senses the temperature at the unit not of the room. Not as versatile as a remote ready with a thermostat.

Variable Flame Height
Via the remote, you can increase and decrease the height of the flame and turn the unit on and off.Also available in thermostatically controlled.

Vent-Free
A device that does not draw outside air to fuel the fire and does not exhaust gases to the outside. Has no need for a flue. Although vent-free units offer high efficiency, some areas may not permit their use. Please check with your local building official.

Venting
The system of pipes that draws air in from the outside to aid combustion and exhausts smoke and gases to the outside.

Zero Clearance Fireplace
A factory-built fireplace that can be placed safely next to combustible material without risk of fire. These devices typically vent directly to the outside and do not require a chimney.