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Part J Heat Producing Appliances

Section 0: General Guidance


0.1 Application of the Regulations

0.1.1 The aim of Part J of the Second Schedule to the Building Regulations is to allow for the installation of heat producing appliances while giving adequate protection to the occupants from incomplete combustion or products of combustion and limiting the risk of fire to the building or fuel storage.

0.1.2 Part J of the Second Schedule to the Building Regulations 2014 applies to all installations (both by way of new work or replacement) but this Technical Guidance Document (TGD) gives guidance on Heat Producing Appliances having power ratings and fuel storage capacities up to the limits specified in Sections 2, 3 and 4.

0.1.3 Part J of the Second Schedule to the Building Regulations 2014 applies to the storage of fuels for all combustion appliances but Section 5 gives guidance for storage with limited capacity applicable to domestic scenarios.

0.2 Explanation of Terms

In this Document, the following definitions apply:

Appliance refers to a Heat Producing Appliance as defined in Regulation J7;

Compartment an appliance compartment is an enclosure specifically constructed or adapted to accommodate one or more combustion appliances;

Chimney structure consisting of a wall or walls (e.g. masonry or stainless steel) enclosing a flue or flues. They consist of different components which can be assembled, e.g. either

  • as a system chimney, that is installed using a combination of compatible chimney components, obtained or specified from one manufacturing source with product responsibility for the whole chimney (e.g. stainless steel chimneys), or

  • as custom-built chimney, that is installed or built on-site in accordance with an execution standard or local building regulations, using a combination of compatible chimney components that can be from one or more sources;

Flue passage for conveying the products of combustion to the outside atmosphere;

Flue liner wall of a chimney consisting of components the surface of which is in contact with products of combustion;

Connecting flue-pipe component or components connecting the heating appliance outlet and the chimney;

Flue block: factory-made single - or multi-wall chimney component with one or more flues;

Gas fire appliance constructed in a single cabinet incorporating a definite air path, a flue spigot for the controlled discharge of combustion products either directly into an existing flue or by passing through a purpose made closure plate. The radiant elements may be made to simulate burning solid fuel and/or may be partially enclosed by a heat resistant glass front plate;

Decorative Fuel-Effect fire (DFE) appliance whose function is primarily aesthetic, being designed to simulate an open solid fuel fire and which is intended to be installed within an open fireplace, so that
the products of combustion pass unrestricted to the chimney or flue. It therefore does not incorporate a flue connection;

Inset Live Fuel-Effect fire (ILFE) appliance consisting of a purpose designed unit in a combination, which incorporates a flue box, fire bed and fire fret constructed in a manner, which controls both the combustion air and the products of combustion. The appliance is intended for installation within or partially in front of a builders opening. The unit may incorporate a method of recovering some heat from the combustion products to provide a convected heat output;

Open flued appliance appliance designed to be connected to an open-flue system, its combustion air being drawn from the room or space in which it is installed;

Room sealed appliance: appliance whose combustion system is sealed from the room in which the appliance is located and which obtains air for combustion from a ventilated uninhabited space within the premises or from air outside the premises and which vents the products of combustion directly to open air outside the premises;

Balanced flue room-sealed appliance which draws its combustion air from a point adjacent to the point at which the combustion products are discharged, the inlet and outlet being so disposed that wind effects are substantially balanced;

Fanned flue systems flue system in which the removal of flue products depend on a fan;

Open-flued fan assisted appliance appliance incorporating a fan upstream or downstream of the burner taking combustion air from a room;

Flueless appliance appliance designed for use without connection to a flue system, the products of combustion being allowed to mix with the air in a room or space in which the appliance is situated;

Fireplace recessis a structural opening formed in a wall or chimney breast, from which a chimney leads and which has a hearth at its base;

Hearth is a base intended to safely isolate a combustion appliance from people, combustible parts of the building fabric and soft furnishings;

Non-combustible material: see Technical Guidance Document B for guidance on non-combustible materials;

Permanent Ventilation opening any means of permanent ventilation which –

  • opens directly to the external air, and

  • except in the case of a screen, fascia, baffle, etc., has the smallest dimension of at least 8 mm, but does not include a flue to a chimney;

Air vent non-adjustable purpose provided arrangement designed to allow permanent ventilation;

Condensate: liquid products formed when the flue gas is at or below the water dew point;

Solid biofuel: a solid fuel derived from plants and trees and includes logs, wood chip, wood pellet and other processed plant materials.

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