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LWF Case studies
Case Study: Mechanical Smoke Control rather than Natural
ProjectA new block of flats in Rayleigh Essex, comprising of two floors with possible expansion to a third to accomodate a further 10 flats. LWF were asked to consider an alternative solution in respect of ventilation of smoke.
Difficulties
The issue under consideration was the requirements for a 1.5 meter squared natural vent in a protected corridor. The praciticalities of the building shape and the fact that a third floor would be constructed above meant that the natural vent could not fit into the corridor ceiling.
Solution
The alternative solution adopted a mechancial extract system to replace natural vents. This was achieved by assessing the time flashover occurred and allowing for occupants to initiate evacuation prior to this phenomenon. The movement of smoke was undertaken using zone model CFAST to determine an equivalent extract rate from a motorised fan as compared with a natural vent.
Benefits
Adopiton of an alternative solution resulted in a more practical solution that could fit within the confines of the space available.