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Building & EnginEERing SERvicES ASSociATionGUIDE TO GOOD PRACTICEINTERNAL CLEANLINESS OFVENTILATION SYSTEMSTR/19 Second Edition 2013 www.b-es.org



TR/19 ACKNOWLEDGEMENT B&ES records its appreciation and thanks to the many persons and organisations who have freely given information on various aspects of this work, in particular to the following members of the ventilation Hygiene Branch who contributed their knowledge and experience to this later edition: Craig Booth Paul Downing George Friend Alan Gregory Gareth Keller Steve Lorriman Gary Nicholls Richard Norman Nick Tregaskes Peter Reid Nick Umfreville Special thanks are offered to J Bridges for his assistance in the development of the deposit Thickness Test, and to T Mulhall of the HSE. iSBn 978-0-903783-65-1 Publishing history: First published as DW/TM2 (1991) and TR/17 (1998) Second Edition (2002), TR/19 (2005) and TR/19 (2013) BuilDing & EnginEERing SERvicES ASSociATion Esca House 34 Palace court london W2 4Jg 020 7313 4900 [email protected] www.b-es.org

Building & Engineering Services Association2 INTERNAL CLEANLINESS OF VENTILATION SYSTEMS FOREWORD As air is invisible there is a tendency to take the quality of the air we breathe for granted. Moreover, given that the average person has an air intake of about 3.4 litres of air every minute, the dangers of an inadequate or polluted air supply are obvious. This, coupled with the risk of fire from build up of grease deposits in kitchen extract systems and the expectations of building occupiers and legislators, has resulted in an ever more stringent level of ventilation system cleanliness being required. This association first published TR/17 in 1998 in order to give guidance to good practice and to establish standards for testing, cleaning and verification of the internal cleanliness of ventilation systems. The guide was re-published in 2005 to include further improvements to best practice and to incorporate the former publication dW/TM2 – internal cleanliness of new ductwork installations. To differentiate this expanded edition from its predecessor publication, it was renumbered TR/19. opportunity has been taken in this second Edition of TR/19 to incorporate reference to the new British and European Standard BS En 15780 cleanliness of ventilation Systems which was introduced in 2011. Also in this new edition changes have been made to highlight the current best practice for ensuring that kitchen extract systems are maintained to minimise the risk of fire associated with grease accumulation. Kitchen extract systems are not covered by BS En 15780. The guide can be used for new build, upgrade and maintenance of ventilation systems and will directly benefit users of the indoor environment as well as specifiers and consultants. Since its inception in 1998, this guide and its predecessors have been widely accepted within the building servicers sector and by the uK insurance industry as the standard to which ventilation systems should be cleaned. B&ES would like to thank members of the B&ES ventilation Hygiene Branch and the many persons and organisations who have contributed to this guide. Bruce Bisset President B&E TR/19

Building & Engineering Services Association 3INTERNAL CLEANLINESS OF VENTILATION SYSTEMSTABLE OF CONTENTS PageForeword 21 introduction 52 new ductwork system cleanliness 83 Design and access to the internal surfaces of the ventilationsystem 114 Specific considerations for system components 15 Air handling units & other system components 15 Access to air handling units 15 Filters 15 linings 16 Moisture 16 Heating, cooling coils and heat exchanger coils 16 Heat recovery coils, thermal wheels, cross-over coils 17 Fans 17 Sound attenuators 17 Turning vanes, volume control dampers 17 Fire dampers 18 ductwork 18 Steel ductwork 18 Flat or oval ductwork 18 Phenolic ductwork 18 glass-fibre reinforced plastic(‘gRP’) 18 Air socks 18 chilled beams 18 Fire cladding and fire-rated ductwork 19 Flexible ducts 19 diffusers and grilles 19 Terminal equipment 19 Plenum void 195 System risk assessment (inspection/monitoring/testing) 21 legislation - health and safety law 21 Monitoring (inspection and testing) frequency 21 recommendation identification and assessment of risk 22 Testing procedures 23 Preferred vacuum test (‘PvT’) 24 deposit thickness test (‘dTT’) 24

Building & Engineering Services Association4 INTERNAL CLEANLINESS OF VENTILATION SYSTEMS Page6 cleaning Methods 26 considerations when using dry cleaning methods 26 considerations when using wet cleaning methods 26 Mechanical brushing 26 compressed air whip/skipper ball 27 Air lance 27 Hand wipe 27 Hand vacuum 27 Hand brushing 27 Hand scrape 287 Specific considerations for kitchen extract systems 29 design and access to the internal surfaces of the kitchen 31 extract system cleaning methods 34 Frequency of cleaning 35 Frequency of cleaning - risk assessment 36 Post-clean verification of cleanliness 37 System testing (inspection/monitoring) 37 System performance testing 398 Hazardous contamination 399 verification of cleanliness 40 Acceptable dust accumulation levels for newly installed 41 ductwork Acceptable post-clean level 41 Timing of post-clean verification testing 41 completion report 4210 Health and safety 42Appendix A Annex F from BS En 15780 44Appendix B Microbiological contamination 46Appendix c legislation and guidance 49Appendix D cleaning contractor selection 50Appendix E Testing methods 52Appendix F Quick guide 1: Air ductwork systems 56Appendix g Quick guide 2: Kitchen grease extract systems 57Appendix H Bibliography 58