TR/19 – the barriers to compliance
There are still an alarming number of ventilation systems which we struggle to make compliant with TR/19, the leading industry document covering ventilation hygiene, issued by BESA, says Gary Nicholls, Managing Director of Swiftclean and co-author of TR/19.
Clean ductwork helps to promote good quality indoor air and, in the case of kitchen extract ductwork systems, to help prevent fires by the removal of flammable grease and dirt. The second edition of TR/19 includes helpful tables which lay out the necessary cleaning frequency, according to each system’s classification (high, medium or low). Heavily used systems such as commercial kitchen extracts will need cleaning the most often and here the rate of deposit accumulation will define the cleaning frequency requirements.
However, in order to comply, we must be able to access the entire system and, in some cases, this is problematic. Ventilation systems must be installed in accordance with DW144 for ordinary ductwork or DW172 for kitchen extract ductwork but, ironically, these do not include the full remit of access points which are required by TR/19 guidelines. A point to note is that the TR/19 guidelines in relation to grease are currently under review and the new version which is due for publication in 2019 is expected to increase the minimum access door frequency requirement from every 3 meters to every 2 meters.
We often encounter problems where there are angles or elbows in the run of ductwork. In order to effectively clean an angle in the ductwork, we need to be able to approach the elbow section from both directions, but we often find that there are insufficient access points close enough to thoroughly clean the angled section. We can usually retrofit an additional door, but it seems nonsensical to have to do this during a new system’s first clean.
After installation has occurred, the importance of maintaining adequate access to the ductwork is not always understood. The interior designer or architect understandably seeks to make a beautiful interior, and does not always bear in mind that TR/19 compliance in ventilation ductwork will be an ongoing issue. In some instances, we find that solid ceilings have been constructed across the ductwork, or false walls installed, obscuring the ductwork.
This can be a major problem. It is hard to tell whether sufficient doors exist, but have been covered up, or if additional doors are needed. Rectifying the situation can be disruptive and costly, requiring service hatches in the beautiful solid ceiling. Although solid ceilings may be more aesthetically pleasing, suspended ceilings are often a better choice for facilitating compliance. When cleaning at height, an access platform may also be required to clean safely and this should be factored in at the design stage. Ideally, future compliance should be on the agenda from the initial design of every building’s ventilation system.
Often, retrofitting additional access doors will solve the problem, but this is not only inconvenient, it also costs the client more than if the full remit of doors needed for TR/19 compliance had been included when the system was installed. In some scenarios, we are quite simply unable to achieve full compliance due to the configuration of the system or a physical barrier which prevents the retrofitting of sufficient access points.
The consequences of non-compliance are considerable. In office settings, a dirty system can contribute to sick building syndrome and increased levels of absence. In residential settings, failure to comply with TR/19 can negatively impact residents’ health and can constitute a breach of a duty of care.
Lack of TR/19 compliance in a kitchen extract system can have far more severe consequences. The airborne grease particles which arise from cooking create deposits which accumulate on the inner surfaces of kitchen extract ductwork. In order to be compliant, this grease layer must be controlled within an average thickness of 200 microns, about half the thickness of an average business card. Allowing the grease layer to accumulate above this will represent an ever increasing and potentially serious fire risk.
Consequently, if your system is non-compliant with TR/19, your buildings insurance may be compromised. Insurance providers may refuse to pay out in the event of a fire if the cause is a non-compliant extract system, because this can fuel a fire and spread it further.
The person responsible for the non-compliant extract system can also face prosecution for negligence, especially if there has been severe damage, injury, or loss of life as a result of a kitchen extract system fire. If found guilty, the responsible person could potentially be given a custodial sentence.
We can solve most of these problems simply by designing ventilation systems in accordance with TR/19 from the outset, ensuring that access points are accessible safely without obstruction and making TR/19 cleaning a priority for the building manager. It makes sound commercial sense, as well as sheer common sense to do this, especially when good health and people’s lives are at stake.