O N L I N E V E R S I O N J Section 1: Provisions which apply generally to combustion installations Performance increased where a room contains more than one appliance (such as a kitchen containing an open-flued boiler and an open-flued cooker). 1.1 In the Secretary of State’s view requirements J1 to J5 will be met if the building provisions for the safe accommodation of combustion appliances: Permanently open ventilation of rooms a. enable the admission of sufficient air for: i. the proper combustion of fuel and the operation of flues ; and 1.4 A room containing an open-flued appliance may need permanently open air vents.
An open- flued appliance must receive a certain amount of air from outside (‘combustion air’ in Diagram 8) dependent upon its type and rating. Infiltration through the building fabric may be sufficient but for certain appliance ratings and forms of construction, permanent openings are necessary (see Diagram 8). ii. the cooling of appliances where necessary; b. enable normal operation of appliances without the products of combustion becoming a hazard to health. c.
incorporate an appropriate means of warning of a release of carbon monoxide for fixed appliances that burn solid fuels, gas fuels (excluding gas appliances used solely for cooking) and oil fuels; Permanent ventilation of appliance compartments 1.5 Appliance compartments that enclose open-flued combustion appliances should be provided with vents large enough to admit all of the air required by the appliance for combustion and proper flue operation, whether the compartment draws its air from a room or directly from outside (see Diagram 8 (b) and (c)). d. enable normal operation of appliances without their causing danger through damage by heat or fire to the fabric of the building; e.
have been inspected and tested to establish suitability for the purpose intended; f. have been labelled to indicate performance 1.6 Where appliances require cooling air, appliance compartments should be large enough to enable air to circulate and high- and low-level vents should be provided (see Diagram 8 (d), (e), (f) and (g)). Note: Whilst, for the purposes of requirement J3, it is considered appropriate to require carbon monoxide alarms only when fixed appliances that burn solid fuel, gas (excluding gas appliances used solely for cooking) and oil are installed, such alarms can still reduce the risk of poisoning from other types of appliance. capabilities.
1.7 Where appliances are to be installed within balanced compartments (see paragraph 0.4(2)), special provisions will be necessary and the appliance and ventilation system manufacturer’s instructions should be followed. Air supply for combustion appliances Ventilation of other rooms or spaces 1.2 Combustion appliances require ventilation to supply them with air for combustion. Ventilation is also required to ensure the proper operation of flues or, in the case of flueless appliances , to ensure that the products of combustion are safely dispersed to the outside air.
Installation of room-sealed appliances or those with a directly connected ducted external air supply will minimise ventilation energy losses from the room and the risk of cold draughts. In some cases, combustion appliances may also require air for cooling control systems and/or to ensure that casings remain safe to touch (see Diagram 8). General guidance on where it may be necessary to install air vents for these purposes is given below.
1.8 If an appliance is room-sealed but takes its combustion air from another space in the building (such as the roof void) or if a flue has a permanent opening to another space in the building (such as where it feeds a secondary flue in the roof void), that space should have ventilation openings directly to outside. Where the roof-space is to be used as a source of air for a combustion installation serving a dwelling, the dwelling roof ventilation provisions suggested in Approved Document C would normally be satisfactory.
1.9 Where flued appliances are supplied with combustion air through air vents which open into adjoining rooms or spaces, the adjoining rooms or spaces should have air vent openings of at least the same size direct to the outside. Air vents for flueless appliances , however, should open directly to the outside air. 1.3 Air vent sizes, which are dependent upon the type of fuel burned, are given in Sections 2, 3 and 4 and are for one combustion appliance only. The air supply provisions will usually need to be 17 Approved Document J Combustion appliances and fuel storage systems O N L I N E V E R S I O N