Maintaining fire safety in ventilation with fire dampers
In January 2017, new advice was issued by the British Standards Institution on the maintenance of fire dampers, recommending that all fire dampers be tested annually. Gary Nicholls, Managing Director of Swiftclean Building Services, explains how BS:9999 2017 has simplified fire damper maintenance. He writes:
“In the past year, Fire Safety Officers and the Health & Safety Executive (HSE) have been clamping down on a much-neglected area of fire safety; fire damper testing. Fire dampers are essentially a set of metal louvres installed within the ventilation ductwork wherever it intersects a fire-resistance rated internal wall. Normally, the metal louvres remain in the open position, allowing the air to flow freely through the ventilation system. It is vital, however, that if a fire breaks out, the louvres will automatically close inside the ductwork, temporarily halting the air flow and restoring the integrity of the fire-resistant barrier.
“It is a legal requirement under the Regulatory Reform (Fire Safety) Order to test fire dampers at regular intervals using a method called drop testing. Under the previous BS:9999 2008, fire dampers were categorised according to their construction type. Most required annual testing, while a few needed to be drop tested only every two years. In accommodation, however, both types had to be tested annually. BS:9999 2017 has now effectively simplified this, so that all fire dampers, regardless of their construction, must now be drop tested and cleaned every 12 months.
“Because of the more vulnerable nature of their occupants, healthcare properties have an additional regulation which must be complied with, in the form of Health Technical Memorandum (HTM) 03-01: Specialised ventilation for healthcare premises Part B: Operational management and performance verification. Depending on the individual property, this may require a more frequent programme of fire damper testing, which is agreed with the local fire prevention officer.
“When a new ventilation system is installed, the property owner should be provided with a full asset register which records the locations of both fire dampers and access hatches, so they can establish a programme of maintenance. However, we have encountered some clients who are unaware that their building has fire dampers, or where they are located, or what type they are. This leaves them with a maintenance nightmare.
“In addition, some fire dampers have not been correctly installed. We have seen some installed upside down; several in the wrong places so they do not line up with the fire-resistant wall; and some left propped open, presumably to pass air circulation tests. Evidently, the installer simply forgot to remove the improvised props, which, in our experience, have ranged from empty drink cans and beer bottles, to lumps of wood and pieces of string. Any fire dampers like this need to be reinstalled correctly and drop tested regularly in the future.
“To clean and test fire dampers regularly, we also need to access them. In ventilation ductwork in general, we need access doors at regular intervals to clean the ductwork in compliance with TR/19, the leading industry guidance document on ventilation hygiene, issued by the Building Engineering Services Association (BESA); but in quite a lot of systems the full gamut of access doors has not been provided.
“Not being able to access the ductwork to insure cleanliness and good air quality is not ideal; but not being able to ensure that fire dampers are working poses a serious fire risk. If sufficient access doors are not provided, they will need to be retrofitted, where possible, to allow cleaning and drop testing to achieve compliance.
“In some cases, once the ductwork was installed, staircases, false walls and ceilings have been installed covering them, making it either prohibitively expensive or just not structurally possible to put this right; so unfortunately, we do see some systems that will never be fully compliant. For this reason, we recommend that ductwork be designed to comply with the requirements of TR/19, including the required cleaning access hatches, from the outset, so that the system design facilitates future maintenance and compliance.
“If fire dampers have not been regularly tested in the past, you will need specialist help to locate them, to gain access and to provide drop testing. Any that do not pass the test will need rectifying by a specialist before you can achieve compliance. Your specialist should then clean the fire damper and, equally importantly, provide clear documentation that demonstrates that it has been tested and cleaned in compliance with BS:9999 2017.
“As fire dampers fulfil a vital function in delaying the spread of fire and giving more time for occupants to be evacuated safely, it isn’t an area in which you can cut corners.”
For further information visit www.swiftclean.co.uk