AIR CONDITIONING, COOLING, VENTILATION TR19 Air – far reaching changes? F
The long anticipated TR19 Air specification has now been published by the BESA, providing clear guidance for the professional cleaning of ventilation systems. Gary Nicholls, MD of Swiftclean and co- author of both TR19 Air and TR19 Grease, looks at the changes and why they were needed
ollowing in the wake of the TR19® Grease specification, published in 2019, the publication of TR19® Air has now completed the separation of compliance in kitchen extract systems and ventilation ductwork, which were both covered in TR19. Unlike TR19, which was a guidance document, TR19® Air is a specification with which ventilation ductwork should comply. Before the involvement of the BESA (Building Engineering Services Association) and the emergence of TR17 and TR19 as expert guidance on ductwork hygiene, the health and cleanliness of ventilation systems was undoubtedly a hit and miss affair. Ductwork was not only largely out of sight, but also mostly out of mind. Forty years ago, when the first pioneers of ductwork cleaning began offering their services, very few building managers were aware of the importance of cleaning their ventilation systems, or the effect that this might have on indoor air quality. Years later it was obvious that some systems were still not regularly cleaned; some were never cleaned. Thankfully, over time, awareness of the importance of cleaning ductwork has risen and the guidance from experts has become firmly established. More recent events, such as the pandemic, and even the tragic Grenfell Tower fire, have brought recognition of the role of ductwork systems in both indoor air quality and fire safety. Fire safety was tackled first, with the publication TR19® Grease. Most of the content of which was lifted from section 7 of TR19 to form its own specification, concentrating on the fire safety aspects of ductwork cleaning in the context of kitchen extract systems. Initially, the rest of TR19 was reissued without section 7, while the importance of ventilation hygiene was examined in more detail. This re-evaluation by BESA’s and the wider industry’s experts resulted in the publication of TR19® Air, and
it is hoped that building owners and managers will now be made more aware of the importance of regular cleaning of ductwork systems in maintaining a healthy indoor atmosphere.
Ductwork hygiene is essential in
order to ensure that the ductwork itself does not introduce airborne pollutants into the incoming air current. These may include dust particles, volatile organic compounds or even bacteria. Not surprisingly, as TR19® Air was born out of TR19, measures such as the classification of ventilation systems as high, medium and low, according to the nature and frequency of their use, remain; together with the now familiar helpful tables giving intervals for cleaning systems of each classification. What is new, however, is a
greater emphasis on inspection and testing, and strong advice about access to the entire system. TR19® Air addresses access with specific advice, especially at the design, construction and installation stages. This reflects the intention to bring the construction standard, DW/144 into line with the ongoing maintenance specification. In the past, DW/144 has been at odds with TR19, as it does not call for as many access points as were required for compliance with TR19. Now, the intention to construct systems with adequate access to achieve
their ongoing compliance is quite clear. It cannot be long before the provisions of DW/144 align with TR19® Air, making compliance easier to understand as well as to carry out. Anyone with any influence over the design of a new or refurbished ventilation system should urge using TR19® Air as the guide for access in the system. Where the system features bends or turns, it must be possible to clean every part, removing any deposits all the way around the angle in the ductwork. Some sections require the technician to enter and crawl through the system, but it is rarely possible to crawl through a turn in the ductwork. This means that there must be an access point both sides of the bend, at no further than a meter away – essentially no more than an arm’s length – so the ductwork can be thoroughly cleaned.
The access must be safeguarded.
There have been too many instances where other utilities such as gas or water pipes or electric cables have been installed across access doors, preventing access. This should not be permitted. It must also be safe for
technicians to enter and exit the ductwork, so it should be possible to position a working platform for technicians to use to enter or exit safely, or to reach into ductwork to clean turns, especially when working at height. It may be possible to retrofit additional access doors to allow the cleaning of the entire system; this is recommended in some older
16 BUILDING SERVICES & ENVIRONMENTAL ENGINEER SEPTEMBER 2024
systems. However, some ductwork is twin-walled and may contain insulation materials, and building managers rarely have records of where these are, so costs of retrofitting can rise unexpectedly. It is invariably cheaper and easier to include the full remit of doors at the initial installation stage. Ventilation ductwork occasionally passes through internal fire-resistant walls. This potentially creates a channel through which fire could travel, so, at this point, a fire damper should be installed. This is a set of metal louvres which, although open most of the time to allow the flow of air, will drop automatically into a closed position in the event of fire. A closed fire damper forms a barrier, delaying the spread of smoke and flames, and restoring the integrity of the fire- resistant wall. It is a legal requirement to function test fire dampers at least every 12 months, to ensure they work properly, so TR19® Air stipulates that there should be an access point no more than a metre from each fire damper.
Cleaning and testing should be
provided by a member of the BESCA Vent Hygiene Register, as they can provide post-clean certification, demonstrating compliance. This documentation constitutes invaluable legal protection against any accusation of negligence.
BESA has claimed that TR19® Air will revolutionise building air quality; it’s certainly a very welcome step forward.
www.swiftclean.co.uk Read the latest at:
www.bsee.co.uk
Page 1 |
Page 2 |
Page 3 |
Page 4 |
Page 5 |
Page 6 |
Page 7 |
Page 8 |
Page 9 |
Page 10 |
Page 11 |
Page 12 |
Page 13 |
Page 14 |
Page 15 |
Page 16 |
Page 17 |
Page 18 |
Page 19 |
Page 20 |
Page 21 |
Page 22 |
Page 23 |
Page 24 |
Page 25 |
Page 26 |
Page 27 |
Page 28 |
Page 29 |
Page 30 |
Page 31 |
Page 32 |
Page 33 |
Page 34 |
Page 35 |
Page 36 |
Page 37 |
Page 38 |
Page 39 |
Page 40 |
Page 41 |
Page 42 |
Page 43 |
Page 44 |
Page 45 |
Page 46
