Glossary of terms A to Z
Bellows: These are triangular shaped bags on a wooden frame with a nozzle at one end and two handles at the other end. They are used to aid combustion in wood burning fireplaces by pumping air into the flames. While they are not needed in gas fireplaces they do make an ideal decorative accessory. Bellows come in a variety of designs and styles with the bags usually made of leather. Click here to find out more.
Btu's: This is an abbreviation of British Thermal Units. It is a measurement used to describe the heating capacity of the fireplace or stove and is calculated according to how much heating is required to raise the temperature of one pound of water by one degree Fahrenheit. This same method is used to measure the cooling capacity of air conditioners.
Burner: This is a pan, underneath the gas logs, that contains the gas used in combustion. Gas, and in some cases a mixture of air and gas, is released through small holes known as burner ports.
B-Vent: This feature is found in gas fireplaces and is designed to take in air from inside the home for use in combustion. Waste created by combustion is released outside. They are also referred to as natural vents.
Catalytic Combustor: Also sometimes known as 'Cats'. These are honey-combed ceramic chambers coated with a metallic catalyst that is used to lower the temperature at which wood will burn. This allows wood to burn slower, longer and therefore, more efficiently. This then means that the fumes that would normally be released via the chimney are burned more effectively thereby releasing fewer pollutants. Click here to read more about these.
Chimney Effect: Rising air in the chimney creates suction. This suction then sucks in more warm air from the room which then escapes out through the chimney. Approximately half the heat produced by a chimney can be lost this way.
Circulating Firebox: Firebox with slatted ventilation where fans can be installed for air circulation. These vents should not be covered.
Clearance: Fire and building codes state that there should be a certain distance between a fireplace or stove and any combustible objects such as furniture. These requirements should always be followed.
Creosote: This is an extremely flammable by-product of combustion that tends to build-up in chimneys. It is formed from condensed wood smoke and indicates incomplete combustion. This is dangerous as it can ignite and cause what is referred to as ' chimney fire' . It is normally a hard black or brown substance that can either be flaky or have a bubbly appearance. Coal tar creosote is a substance most commonly used to preserve wood in the United States and is made up of a combination of chemicals.
Direct Spark Ignition: This is a system whereby gas fires are ignited by a spark from the burner.
Direct Vent: These are gas fireplaces that do not require a chimney but, instead use a flue to carry combustion by-products outside either directly through the wall or up through the roof. It is necessary for these types of fireplaces to have sealed glass doors to keep combustion waste out of the rooms. Air for combustion is brought in from outside. These systems are cheaper and easier to install than chimney systems.
Electronic Ignition: This is a system that uses an electric current to ignite the burner.
Emissions: Waste products caused by combustion which can sometimes be seen as smoke.
EPA: Environmental Protection Agency. Regulations state that wood burning appliances should not release more than 4.1grams of combustion emissions every hour for catalyst products, and no more than 7.5 for non-catalyst products.
Firebacks: A thick cast iron plate that protects the masonry and mortar from the heat of the flames. These also retain heat very well, radiating it back into the room when the fire is no longer lit.
Firebox: This term refers to the box-like section of the fireplace that houses the fuel (wood for example) and where combustion takes place.
Fireplace Doors: As well as being a decorative feature these serve the purpose of closing off the firebox, when the fireplace is not in use, to ensure that heat is not lost through the vent or chimney.
Fireplace Insert: This is an insulated system with a pair of glass doors that can be installed onto the opening of the fireplace. This increases the temperature in the firebox meaning the fire burns more slowly and efficiently. Inserts can come with fans included to blow the warmth into the room. These are particularly useful in wood burning fireplaces as the increased heat and slower burning means that there is a reduced amount of combustion by-products such as smoke. This term is also generally used to describe any retrofit for fireplaces. This includes inserts to convert a wood burning fireplace into a gas fireplace.
Firestop: This refers to a non-flammable material that is used in any openings in the floor and wall to prevent the spread of fire or smoke.
Flue: Small vent through which combustion waste is discharged.
Freestanding Stove: Similar to a fireplace, these appliances normally stand on legs rather than being installed into a wall. These can come as either gas or wood burning stoves.
Part Two G to Z