When navigating the world of fireplaces, gas fires, electric fires, and wood-burning stoves, you’ll encounter a variety of technical terms and industry jargon. Understanding these key terms is essential for making informed decisions about the right heating solutions for your home.
From the different types of chimneys and flues to safety features like carbon monoxide detectors, each component plays a crucial role in both functionality and compliance with safety regulations.
Related Article: What Are The Component Parts of a Fireplace?
Below, we’ll explore the most common terminology used in the fireplace and stove industry to help demystify the process and guide you through your choices.
Please see the list below:
Aperture
The aperture refers to the opening in a wall or chimney breast designed to house a fireplace. This opening is also known as the Builder’s Opening or fireplace recess. Traditionally placed close to the floor, many newer designs feature inset fireplaces that are installed higher up the wall.
Air Vent
Air vents are legally required in rooms with gas or solid fuel fires. Insufficient airflow can cause dangerous gases, like carbon monoxide, to be vented into the living space, potentially leading to fatal consequences.
Back Panel
A back panel is the vertical surface located at the rear of a fireplace or stove, often made of materials like stone, metal, or heat-resistant board, designed to enhance aesthetics, protect the wall from heat damage, and reflect heat into the room for improved efficiency.
Baffle
A baffle is a component within a fireplace, stove, or flue system designed to direct the flow of smoke and gases, improve combustion efficiency, and reduce heat loss by forcing the hot gases to travel a longer path before exiting, thereby enhancing heat exchange and overall performance.
Balanced Flue Gas Fire
A balanced flue gas fire is ideal for homes without an existing chimney. These units are sealed and function by drawing in external air and venting combustion gases outside through a dual pipe system. They are highly efficient since less heat escapes compared to traditional chimney-based systems.
Boxed And Lipped Hearth
A boxed and lipped hearth is a type of fireplace base that features raised edges (lips) around its perimeter, with the hearth sitting above floor level, creating a neat and elevated platform for the fire. Generally 50-60mm in height.
Boxed Flush Hearth
A boxed flush hearth is a type of fireplace hearth that has a streamlined appearance while still providing a defined, raised platform for the fire without any lips or raised edges.
BTU (British Thermal Unit)
BTU measures heat energy and is defined as the energy required to raise the temperature of one pound of water by one degree Fahrenheit. On this site, we use kilowatts (kW) for heat measurement. For reference, 1 kW equals 3413 BTUs.
Builders Opening
A builder’s opening is the rough opening in a wall or structure where a fireplace or stove will be installed, typically framed to 16″ x 22″ as standard by home builders. May require work to ensure proper fitting of a more modern appliance.
Building Regulations
In the UK, Building Regulations govern the construction and installation of chimneys and flues in line with European and British Standards. These rules also require building control approval when constructing new chimneys or relining existing ones, especially if there is a change in the heating appliance.
Cap (Capper)
A cap, often referred to as a chimney cap, is a protective cover placed on top of a chimney flue, designed to prevent rain, debris, and animals from entering the chimney while also helping to reduce downdrafts and improve ventilation for more efficient smoke expulsion.
Carbon Monoxide (CO)
Carbon monoxide is a toxic, odorless, and colorless gas produced by the incomplete combustion of fuels such as wood, coal, oil, or gas. Often called the Silent Killer, CO can be lethal when inhaled over time, either in large or small amounts.
Carbon Monoxide Detector
Installing a carbon monoxide detector is legally required in rooms with new solid fuel-burning appliances. While it may not be required for gas appliances, it’s a wise precaution to protect your family from CO poisoning. The detectors available at Direct Fireplaces come with a seven-year warranty and a test button to ensure proper functionality.
Catalytic Converter
Catalytic converters in gas fires use a catalyst, typically platinum, to break down harmful gases like carbon monoxide and hydrocarbons into less harmful substances, such as carbon dioxide and nitrogen.
Chamber Lining
Chamber lining panels refer to the material that lines the interior of a fireplace or stove’s combustion chamber, designed to protect the structure from high temperatures, improve heat retention and distribution, and enhance overall efficiency while also providing a barrier against corrosive gases and soot buildup.
Chimney
Chimneys operate by circulating warm air upward, allowing smoke and gases to escape safely from the home.
- Class 1 Chimneys: These traditional chimneys are wide, allowing for the installation of deeper fires and stoves.
- Class 2 Chimneys: Found in newer homes, these shallower chimneys are built into external or internal walls and are more suited to slimline fires.
Chimney Breast
A chimney breast is the protruding section of a wall that houses a chimney and its flue, typically extending from the roofline down to the floor, and is designed to support the fireplace or stove while providing space for smoke and gases to vent safely outside.
Closure Plate
A closure plate, also known as a register plate, is a flat metal or other material panel used to seal the opening of a chimney or flue, helping to regulate airflow and improve the efficiency of heating systems while preventing unwanted drafts.
Constructional Hearth
A constructional hearth is a non-combustible platform that is at least 150 mm thick, designed to support a fireplace or stove while protecting the surrounding area from heat and embers in compliance with safety codes.
Convection Heat
Convection heat is generated when warm air rises and cooler air moves into warmer areas, circulating heat throughout a room.
Corbels
Corbels are decorative brackets that support the mantel or shelf above the fireplace opening, made from wood or stone they add visual interest and architectural detail while also providing structural stability to the mantel.
CORGI
Formerly the gas safety registration body in the UK (1970–2009), CORGI is now a voluntary registration system for various trades. As of 2012, all gas engineers must be registered with the Gas Safe Register by law.
Creosote
Creosote is a flammable, tar-like substance that accumulates inside chimneys and flues as a byproduct of burning wood and other organic materials, forming when smoke cools and condenses; it poses a significant fire hazard and requires regular cleaning to prevent chimney fires.
Damper
A damper is a movable plate or mechanism installed within a chimney or fireplace that regulates airflow, allowing users to control the intensity of the fire and prevent heat loss when the fireplace is not in use by sealing off the flue.
DEFRA
The Department for Environment, Food & Rural Affairs (DEFRA) is responsible for environmental protection in the UK. Under the Clean Air Act of 1993, it’s illegal to emit smoke in designated smoke control areas unless using approved fuels or appliances.
Direct Spark Ignition
Direct spark ignition is an electronic method for lighting gas burners, eliminating the need for a continuously lit pilot light.
Eco Design Ready (2022)
The Eco Design 2022 directive by the European Union sets stricter regulations for solid fuel-burning appliances to enhance energy efficiency and reduce harmful emissions, promoting cleaner technologies and supporting broader environmental goals.
Efficiency
Fireplace efficiency refers to how effectively energy used for heating is converted into actual heat output. Most gas and solid fuel fires aren’t fully efficient since some heat escapes through the chimney. However, glass-fronted fires can be over 80% efficient, and electric fires are considered 100% efficient.
Elbow
An elbow is a pipe fitting that changes the direction of a flue or vent pipe, typically used in chimney and ventilation systems to navigate around obstacles while ensuring a smooth and efficient flow of smoke and gases.
Electric Fires
Electric fires are a versatile heating option that doesn’t require a chimney. Typically offering up to 2kW of heat, they often have adjustable heat settings and a flame-only mode. Electric fires are highly efficient, as all the energy consumed is converted into heat.
Emissions
Emissions are the gases released during combustion, such as carbon monoxide, carbon dioxide, nitrogen oxides, and particulate matter, vented outside via chimneys or flues.
Fender
A fender is a low, protective barrier placed in front of a fireplace, often made of metal or other fire-resistant materials, designed to contain embers and prevent them from escaping into the room, while also serving as a decorative element that enhances the fireplace’s aesthetic appeal.
Firebrick
Firebrick, also known as refractory brick, is a type of brick specifically engineered to withstand high temperatures and thermal shock, commonly made from vermiculite or concrete used in the construction of fireplaces, kilns, and furnaces to provide insulation, durability, and heat retention.
Fire Dogs or Andirons
Fire dogs, also known as andirons, are metal supports used in a fireplace to hold logs in place, allowing air to circulate around the fire for improved combustion, while also serving as decorative elements that enhance the aesthetic appeal of the fireplace.
Fireplace Inserts (Inset)
Fireplace inserts are heating units that retrofit into existing masonry or factory-built fireplaces, utilising wood, gas, or wood pellets to deliver enhanced efficiency and improved heat output.
Firestop
A firestop is a barrier designed to prevent the spread of fire and smoke through openings in walls, floors, or ceilings, typically made of materials such as fire-resistant foam, caulk, or intumescent strips, and is essential for maintaining the integrity of fire-rated assemblies in buildings.
Flueless Gas Fires
Flueless gas fires don’t require a chimney, as combustion gases are filtered through a catalytic converter. These fires are highly efficient but require proper ventilation and are typically used as supplementary heating sources.
Flexible Flue Liner
A flexible flue liner is a bendable, stainless steel tube installed inside an existing chimney to improve safety and efficiency. It helps contain the combustion gases, prevents leaks, and protects the masonry from heat and corrosive by-products. Flexible flue liners are commonly used for wood-burning stoves or gas fires, especially in chimneys that are older or have bends.
Free Standing Stove
A freestanding stove is a heating appliance that rests on a pedestal and operates independently of any fireplace, providing flexible placement options on 4 legs.
Fret
A fret is the decorative front panel of a fireplace that covers the fire basket and ashpan. Many modern gas and electric fires also feature interchangeable frets.
Gas Safe Register
Since April 2009, the Gas Safe Register has replaced CORGI as the UK’s official gas safety body. By law, all gas engineers must be listed on the Gas Safe Register to carry out gas-related work.
Header
A header is a structural beam that spans the top of an opening undernearth the shelf, providing support to the surrounding materials and ensuring stability while distributing weight evenly across the structure.
Hearth
The hearth is the fire-resistant floor area of a fireplace, often made from brick or stone. It helps prevent fires from spreading within the home. For solid fuel fires, a special “slabbed” hearth may be necessary.
HETAS
HETAS is the UK’s official body for approving solid fuel heating systems, including appliances, fuels, and services. They also maintain a register of competent installers.
Jamb
A traditional term, jamb is the vertical side component of a doorway, window, or fireplace opening, providing structural support and serving as the frame that holds the door or window in place.
Knockout
A “knockout” refers to the process of enlarging a fireplace aperture by removing portions of the surrounding structure to accommodate a larger firebox or improve airflow.
Limestone
Limestone is a sedimentary rock formed from compacted fossils and organic matter. It comes in various colors, from white to beige, depending on its origin.
Lintel
A lintel is a horizontal structural steel or concrete reinforced beam placed over a fireplace opening to support the weight of the materials above it, ensuring stability and integrity in the building structure.
LPG (Liquefied Petroleum Gas)
LPG is an alternative to natural gas, particularly in areas without a mains gas supply. Fires that run on LPG must be specifically designed for it, as LPG has a different calorific value than natural gas.
Mantle
A mantel, also known as a mantlepiece, is a decorative shelf or framework that surrounds the upper portion of a fireplace, often serving as a focal point in a room and providing a surface for displaying decorative items such as photos, clocks, or candles.
Marble
Marble is a natural stone formed under intense heat and pressure, often used for its decorative appeal in fireplace surrounds.
Micro Marble
Micro marble is a manufactured material made from crushed marble mixed with resins. It resembles natural marble but lacks the veining patterns.
Oxygen Depletion Sensor
This sensor monitors oxygen levels in a room and will shut off the gas fire if oxygen falls below safe levels, ensuring the room remains safe.
Period Fireplaces
Period fireplaces recreate styles from past eras, such as the Georgian, Victorian, Edwardian, and Art Nouveau periods, often featuring detailed designs and materials like cast iron or marble.
Pilot
A pilot is a small, continuous flame used in gas appliances, such as fireplaces and heaters, to ignite the main burner when the appliance is turned on, ensuring a safe and efficient ignition process.
Power Flue Gas Fires
These gas fires use an electric fan to vent combustion gases outside through a pipe, allowing more flexibility in fire placement within the home.
Pre-cast Flues
These are shallow chimneys found in modern homes, typically situated within walls and allowing for the installation of gas fires without the need for a full chimney breast.
Rebate
A fireplace rebate refers to the recessed section at the back of a fireplace surround, designed to create additional depth for fitting appliances like inset gas or electric fires, especially when wall space is limited or to accommodate different fire types.
Fireplace Rebates: All You Need To Know
Slabbed Hearth
A slabbed hearth is required for solid fuel fires. It involves cutting the hearth into three parts, filling the gaps with cement and vermiculite to withstand temperature changes.
Slip
Fireplace slips are narrow panels, typically made from materials like stone or metal, that are fitted around the inner edges of the fireplace opening. They serve both a decorative and functional purpose, helping to frame the fire while covering any gaps between the fire surround and the fireplace opening.
Smoke Control Areas
Established after the 1952 London smog, smoke control areas restrict what types of fuel can be burned. Only authorised fuels or exempt appliances are allowed to emit smoke in these areas.
Smokeless Fuels
Smokeless fuels are solid fuels that burn with little to no smoke, making them ideal for use in areas with smoke control regulations; they typically include anthracite, coke, charcoal and hexamine fuel tablets, offering cleaner combustion and reduced air pollution compared to traditional solid fuels like coal or wood.
Storm Collar
A storm collar is a fitting used around the chimney pipe where it passes through the roof, designed to create a watertight seal that prevents rain and snow from entering the chimney system, thereby protecting the interior of the home from moisture damage.
Surround
A fireplace surround is the decorative framework or enclosure that surrounds a fireplace opening, typically made of materials like stone, brick, or wood, and serves both aesthetic and functional purposes, enhancing the overall appearance of the fireplace while protecting the wall from heat and soot.
Twin Wall Flue
A twin wall flue is a type of chimney system made up of two layers of stainless steel with insulation in between. This design helps maintain the flue’s temperature, improving efficiency and safety by preventing condensation and reducing the risk of heat transfer to nearby combustible materials. Twin wall flues are often used in homes without traditional chimneys to safely vent wood-burning stoves or other heating appliances.
Victorian Fireplaces
These fireplaces, inspired by designs from the Victorian era, often feature cast iron and elaborate floral or geometric patterns.
