- General Interest
One factor that is often forgotten, particularly when specifying for kitchens, is the need to insulate the kitchen extract ductwork. However, as Michael Hunter, technical manager at Saint-Gobain Isover, explains, sticking to specification for insulation can minimise the risk of fire and safeguard the wellbeing of building users.
When creating kitchen spaces in commercial buildings, specifiers have to be very particular about the fire safety solutions they use. Not only do they have ovens and other large appliances to consider, but the kitchen extract systems used to remove hot air from cooking also present a specific hazard, due to the potential for grease to accumulate in the ductwork.
Under certain circumstances, and without suitable precautions, this accumulated grease can catch fire, which can spread quickly through the duct. Flames and heat within the ductwork then ignite surrounding wall materials, leading to a full-scale safety incident.
With this in mind, it is essential for specifiers and the building owners to understand that dedicated fire safety measures need to be factored into kitchen extract design, as well as the rest of the space.
Passive versus active
Currently, there is a lot of debate over whether to choose active fire protection systems, such as sprinklers, or passive measures, such as insulation, to effectively manage a fire.
Furthermore, it seems to be a little known fact that, under Regulation British Standard (BS) 9999: 2008 Code of Practice for fire safety in the design, management and use of buildings, (section 126.96.36.199), “fire dampers (mechanical systems designed to seal ductwork in the event of a fire) should not be used in kitchen extract”.
To optimise fire safety within the kitchen extract system and the building as a whole, it is essential to achieve the three pillars of fire safety: stability; integrity; and insulation. This means ensuring the structural stability of the duct, maintaining integrity against the passage of flame and minimising the transfer of heat between rooms for the duration of the fire protection interval. Such a feat can only be achieved with passive fire protection.
The role of passive fire protection
The principle role of fire protection measures in kitchen extract design is to create a window of opportunity, typically 60 or 120 minutes in duration, for building occupants to evacuate in the event of a fire, as well as allow fire fighters to respond.
Passive fire protection measures, such as insulation, achieve this by delaying the transmission of fire between rooms and reducing the potential impact on a development’s structural integrity. However, to ensure this window lasts as long as possible, the solution must be correctly specified and installed.
All wrapped up
Fire safety legislation currently states that both BS 476: Part24 and European Standard (EN) 1366 solutions are acceptable in the UK. As a result, many specifiers currently look to insulation systems certified to the former guideline to ensure fire safety for kitchen ductwork. However, when UK building regulations next come under review, it is highly likely that EN1366 for fire resistance will be the only method for compliance. This means specifiers should consider solutions accredited to both standards to ensure they meet regulations into the future.
With this in mind, we have recently launched the innovative U Protect Black Alu fire protection ductwork solution. Featuring high-performance ULTIMATE™ mineral wool in slab and wired mat products, the insulation offers up to 120 minutes’ fire resistance in HVAC applications, including smoke and kitchen extraction ducts. It is uniquely certified to both BS 476: Part 24 and EN 1366, which will help ensure that a building’s kitchen extract systems are compliant with both current and future regulatory requirements.
Weighing only 66 kg/m3, U Protect Black Alu is 73 per cent lighter and 33 per cent thinner than traditional stone wool. This makes it easier for contractors to install and reduces the weight on the brackets holding it in place, eliminating the need to source new fixings. The solution is also easy to cut to size, whether for circular or rectangular ducts, helping to ensure complete insulation of the entire kitchen extract system and optimum fire safety.
In addition to all this, U Protect Black Alu’s distinctive black aluminium covering helps people see at a glance that the kitchen extract system is completely protected with a high-performance insulation solution specially designed to ensure fire resistance. This can be reassuring for building owners, giving them the peace of mind that their property and the people using their premises every day are as safe as possible in the event of a fire.
Fired up for fire safety
Fire safety legislation is being updated all the time, and it is highly likely that standards will become even more rigorous in the coming years. To ensure their kitchen facilities remain compliant, specifiers and building owners look to active life safety systems.
However, it is vital that passive fire protection measures are also considered and the most appropriate solutions are selected for the needs of a property. In doing so, specifiers will not only ensure the project meets regulatory requirements for fire safety, but they can be confident that they are safeguarding the wellbeing of occupants, and protecting the building too.