BS-5871-3-2005.pdf

BRITISH STANDARD BS 5871-3:2005 Specification for the installation and maintenance of gas fires, convector heaters, fire/back boilers and decorative fuel effect gas appliances Part 3: Decorative fuel effect gas appliances of heat input not exceeding 20 kW (2nd and 3rd family gases) ICS 97.100.20 ? BS 5871-3:2005 This British Standard was published under the authority of the Standards Policy and Strategy Committee on 13 April 2005 © BSI 13 April 2005 First published September 1991 Second edition July 2001 Third edition April 2005 The following BSI references related to the work on this British Standard: Committee reference GSE/30 Draft for Development 03/320606 DC ISBN 0 580 45650 1 Committees responsible for this British Standard The preparation of this British Standard was entrusted to Technical Committee GSE/30, Gas installations (1st, 2nd and 3rd family gases), upon which the following bodies were represented: Boiler and Radiator Manufacturers Association Ltd. British Flue and Chimney Manufacturers Association BSI Consumer Policy Committee Catering Equipment Suppliers Association Centrica plc Council for Registered Gas Installers Department of Trade and Industry Health and Safety Executive Heating and Ventilating Contractors Association ICOM Energy Association Institute of Domestic Heating and Environmental Engineers Institution of Gas Engineers and Managers L P Gas Association Society of British Gas Industries Co-opted members Amendments issued since publication Amd. No.DateComments BS 5871-3:2005 © BSI 13 April 2005 i Contents Committees responsibleInside front cover Forewordii 1Scope1 2Normative references1 3Terms and definitions2 4Exchange of information and planning4 5Appliances4 6Materials and components6 7Location6 8Ventilation8 9Flueing10 10 Appliance fixing18 11 Fire and related safety precautions20 12 Gas supply24 13 Electricity supplies and wiring25 14 Commissioning25 15 Instructions and use of fireguards26 16 Advice to be given to the user26 Annex A (informative) Calculation of clearance flue flow28 Bibliography38 Figure 1 Type of fuel effect gas appliances covered by BS 58717 Figure 2 Flue/fireplace sizing chart for decorative fuel effect gas appliances13 Figure 3 Appliance installation in typical flue box 15 Figure 4 Unsuitable terminations 16 Figure 5 Typical fireplaces in which appliance may be installed 21 Figure 6 Constraints required to determine chimney size using method 2 for cases 4, 5 and 6 22 Figure A.1 Bubble leak indicator33 Figure A.2 Basic test box34 Figure A.3 Test box and flue for appliances that can be installed in a metal flue box35 Figure A.4 Collecting hood36 Figure A.5 Collecting hood positioning37 Table 1 Designation system for metal chimneys for use with gas fires12 Table A.1 Test internal air pressure28 Table A.2 Wobbe number for test gases29 Table A.3 Inlet pressure for tolerances29 Table A.4 K values for reference gases32 BS 5871-3:2005 ii© BSI 13 April 2005 Foreword This part of BS 5871 has been prepared under the direction of the Engineering Sector Board and is a revision of BS 5871-3:2001, which is withdrawn. This new edition of BS 5871-3 comes into effect on 11 July 2005. This revision reflects experience gained in the use of the 2001 edition for the installation of decorative fuel effect gas appliances1) and also provides additional guidance on the use of fanned draught flueing and flue sizing, and includes requirements for fires installed in raised builders openings (hole-in-the-wall fireplaces). BS 5871-1: Gas fires, convector heaters, fire/back boilers and heating stoves (2nd and 3rd family gases). BS 5871-2: Inset live fuel effect gas fires of heat input not exceeding 15 kW and fire/back boilers (2nd and 3rd family gases). BS 5871-3: Decorative fuel effect gas appliances of heat input not exceeding 20 kW (2nd and 3rd family gases). BS 5871-4: Independent gas-fired flueless space heaters for nominal heat input not exceeding 6 kW (2nd and 3rd family gases) (in the course of preparation). To identify which part of BS 5871 to use when fitting an appliance which simulates a solid fuel fire, reference should be made to Figure 1 which serves to illustrate appliance types and link them to the appropriate part of BS 5871. It should be noted that the only fuel effect appliances covered by this part of BS 5871 are those detailed in b) of the commentary and recommendations on Clause 5 of this standard. The manufacturers instructions supplied with fanned draught appliances in which the fan is either integral with the appliance or with the flue system will make reference to the appropriate part of BS 5871. It should be noted that the only appliances covered by this part of BS 5871 are those that are CE marked. However, BS 5871-3 may also be referred to for the installation of used appliances, where appropriate, providing the manufacturers instructions are available. In such circumstances, the installer should satisfy himself that the appliance is safe in construction and condition, and can be used without constituting a danger. Attention is drawn to Clause 5 concerning this particular aspect. Arising from European standards harmonization, some British Standards appliance specifications are now being replaced by European standards. One consequence of this process is that the reference clearance flue flow test, currently included in some of the British Standards covering the safety of appliances dealt with by BS 5871, will not be given in European appliance standards. This test has hitherto been used to determine the flue flow, under laboratory conditions, that an appliance will just clear its combustion products. The test has been used as a key factor in determining whether or not certain appliances of 7 kW2) heat input or less require purpose provided ventilation for their installation. Although BS 5871 is an appliance installation standard, the drafting committee has decided to include the clearance flue test as an informative annex. It is hoped that this arrangement will provide Notified Test Houses under the Gas Appliance Directive with a continuing means to evaluate appliances for installation within the UK which claim that no purpose provided ventilation is necessary for their installation. 1)Sometimes referred to as a decorative gas fire or DGF. 2)Due to tolerances, this applies to a heat input of 7 kW on both net and gross calorific value. See Clause 1, Scope, Note 2. BS 5871-3:2005 © BSI 13 April 2005 iii This standard allows manufacturers instructions to specify a method of installation, testing, commissioning or maintenance which differs in points of detail from this standard. This reference to manufacturers instructions is allowed only where it will result in at least an equivalent level of safety. In such circumstances, it is important that the manufacturers instructions are followed. NOTEIn the preparation of this standard the opportunity has been taken to present it in the format of a practice specification as defined in PD 6501-1. This format allows the requirements of the specification to be supported by recommendations. To comply with this specification, the user has to comply with all its requirements. He may depart from recommendations but this would be his own responsibility and he would be expected to have good reasons for doing so. This publication does not purport to include all necessary provisions of a contract. Users of are responsible for its correct application. Compliance with a British Standard does not of itself confer immunity from legal obligations. In particular, attention is drawn to the following: The Gas Safety (Installation and Use) Regulations 1998 1 The Gas Safety (Installation and Use) (Northern Ireland) Regulations 2004 2 The Gas Appliances (Safety) Regulations 1995 3 The Building Regulations 2000, as amended 4 The Building (Scotland) Regulations 2004 5 The Building Regulations (Northern Ireland) Statutory Rules 2000, as amended 6 The Gas Safety (Application) (Isle of Man) Order 1996 7 Summary of pages This document comprises a front cover, an inside front cover, pages i to iv, pages 1 to 39 and a back cover. The BSI copyright notice displayed in this document indicates when the document was last issued. iv blank BS 5871-3:2005 © BSI 13 April 2005 1 1 Scope This part of BS 5871 specifies installation and maintenance requirements for open flued decorative fuel effect gas appliances of heat input not exceeding 20 kW (see Note 2) burning 2nd and 3rd family gases in rooms or internal spaces in domestic (see Note 4) or commercial premises, including public houses and restaurants. The provisions contained within this standard cover the selection of a suitable appliance, the ventilation and flueing requirements, and other measures necessary to ensure a safe installation. This standard applies to the installation of decorative fuel effect gas appliances in builders openings, fireplace recesses, flue boxes or under associated independent canopies. (See Figure 5.) It does not cover the installation of flueless or room-sealed appliances. This standard is not applicable to mobile and portable appliances in conformity with BS EN 449 or to appliances in touring caravans. NOTE 1Attention is drawn to the foreword concerning fuel effect appliances which burn gas for a decorative effect. The only types of such appliance covered by this part of BS 5871 are those detailed in b) of the commentary and recommendations on Clause 5 of this standard. Further guidance in this respect is given in Figure 1. NOTE 2Heat inputs in this document are based on net calorific value. Figures based on gross calorific value are given in parenthesis where deemed necessary. See also Clause 5, commentary and recommendations b). NOTE 3Attention is drawn to the foreword concerning the installation of used appliances. NOTE 4As well as normally constructed dwellings, domestic premises include any permanently sited caravan holiday homes, residential park homes and permanently moored boats. See IGE/UP/8 8. NOTE 5Appliances of over 20 kW: although many of the requirements within this standard will equally apply to appliances with a rated heat input in excess of 20 kW, additional or alternative requirements may also be applicable in order to achieve a safe installation. Reference should be made to the Building Regulations and supporting guidance or requirements thereto. 2 Normative references The following normative documents contain provisions which, through reference in this text, constitute provisions of this British Standard. For dated references, subsequent amendments to, or revisions of, any of these publications do not apply. For undated references, the latest edition of the publication referred to applies. BS 715, Specification for metal flue pipes, fittings, terminals and accessories for gas-fired appliances with a rated input not exceeding 60 kW. BS 1289-1, Flue blocks and masonry terminals for gas appliances Part 1: Specification for precast concrete flue blocks and terminals. BS 5440-1, Installation and maintenance of flues and ventilation for gas appliances of rated input not exceeding 70 kW (1st, 2nd and 3rd family gases) Part 1: Specification for installation of flues. BS 5440-2, Installation and maintenance of flues and ventilation for gas appliances of rated input not exceeding 70 kW (1st, 2nd and 3rd family gases) Part 2: Specification for installation and maintenance of ventilation for gas appliances. BS 5482-1, Domestic butane- and propane-gas-burning installations Part 1: Specification for installations at permanent dwellings. BS 5482-2, Domestic butane- and propane-gas-burning installations Part 2: Installations in caravans and non-permanent dwellings. BS 6891, Specification for installation of low pressure gas pipework of up to 28 mm (R1) in domestic premises (2nd family gas). BS 7435-2, Fibre cement flue pipes, fittings and terminals Part 2: Specification for heavy quality fibre cement flue pipes, fittings and terminals. BS 7671, Requirements for electrical installations IEE Wiring Regulations (Sixteenth edition). BS 7977-1:2002, Specification for safety and rational use of energy of domestic gas appliances Part 1: Radiant/convectors. BS EN 1856-1, Chimneys Requirements for metal chimneys Part 1: System chimney products. BS EN 1856-2, Chimneys Requirements for metal chimneys Part 2: Metal liners and connecting flue pipes. BS 5871-3:2005 2© BSI 13 April 2005 3 Terms and definitions For the purposes of this part of BS 5871, the following terms and definitions apply. 3.1 air vent non-adjustable purpose provided unit/assembly designed to allow permanent ventilation 3.2 air vent free area unobstructed cross-sectional area of an air vent, i.e. the sum of the areas of the individual apertures 3.3 associated independent canopy non-combustible canopy situated at the base of the flue system and which is permanently fixed above the appliance to facilitate the passage of the products of combustion into the flue 3.4 builders opening enclosure constructed by the builder to accommodate fireplace components 3.5 chimney breast projection beyond the thickness of a wall that contains the fireplace and flue 3.6 chimney pot prefabricated unit fitted at the flue outlet of a chimney 3.7 decorative fuel effect gas appliance appliance designed to burn gas for a decorative effect 3.8 factory made insulated chimney complete assembly of all the essential factory made insulated sections, fittings and accessories necessary to convey the products of combustion to the outside air 3.9 fanned flue system flue system in which the removal of flue products is dependent on a fan 3.10 firebed part of a decorative fuel effect gas appliance on which the gas burns 3.11 fireplace opening aperture formed in the face of the builders opening, fireplace recess, flue box or fire surround, if fitted 3.12 fireplace recess recess formed by the inclusion of fireplace components in the builders opening 3.13 flue box non-combustible enclosure that provides a substitute builders opening or fireplace recess BS 5871-3:2005 © BSI 13 April 2005 3 3.14 flue pipe pipe enclosing a flue; for a double walled flue system or factory made insulated system it is the inner pipe NOTEEuropean chimney standards refer to a flue pipe as a “chimney”. This is defined in BS EN 1443 as “a structure consisting of a wall or walls enclosing a flue or flues”. 3.15 flue system continuous flue, or a complete assembly of flue components, from a builders opening, fireplace recess, flue box or associated independent canopy to a chimney pot, terminal or flue outlet 3.16 gather smooth transitional reduction in area from above the builders opening or fireplace recess into the flue 3.17 hearth slab of fire-resisting material to prevent overheating of the surface be