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Under the Building Regulations, many buildings, particularly those with an occupied level over 18m in height, require a Fire Fighting Shaft or Core. For buildings under 18m, please refer to our Apartments home page.
Please refer to the leaflet Smoke Control in Apartments for details on the alternative design approaches.
This kind of shaft is adjacent to an enclosed staircase and lobby at each level. The lobby is designed to act as a bridgehead from which the fire officers are able to commence operations when dealing with a fire. It is therefore important to ensure that when the fire service arrives, both the stairs and the lobby are free of smoke. This is achieved by the use of smoke ventilation, as described in BS 5588 Part 5: 2004.
If the staircase or lobby have external walls, openable windows are acceptable to meet the requirements of the standard.
If external walls are not available, then Colt are able to offer either a Shaft System or a Pressurisation System.
Shaft systems can be either a Standard Smoke Shaft as described in BS 5588 Part 5, a BRE Shaft referred to in BS 5588 Part 5 and described in BRE Report 79204 or the recently developed Colt Mechanical Shaft.
Briefly, a Standard Shaft requires a 1.5m² AOV (Automatic Opening Ventilator), which Colt can supply in the form of a Defender or Doorman unit opening into a 3m² shaft open at the top and bottom.
The BRE shaft is very similar, requiring a 3m² shaft, but with an opening at the top of the shaft only.
The Colt Mechanical Shaft uses a fan system to draw smoke out of the fire fighting lobby and requires a shaft of only 0.6m².
All three shaft systems require a ventilator to the top of the fire fighting stair, for which the Colt Seefire is ideal. This unit can also be used as a weather shutter on the top of the shaft.
Pressurisation Systems are much more complex. An air supply system maintains a positive air pressure in the fire-fighting shaft, which prevents smoke from entering from the fire location. Excess air pressure needs to be released from the staircase and an air leakage path to outside also needs to be provided. This can be either by natural ventilators to outside, or a common natural shaft through the building, or a powered shaft.
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