Smoke-ventilation system extends escape travel distances
Escape travel distances in the event of fire have been increased beyond the maximum of 7.5 m specified in Approved Document B in Chettles Yard student accommodation by the installation of SE Controls’ Shevtec extended-travel-distance system. This approach to smoke ventilation makes possible fewer staircases and uses smoke shafts less than half the area of a conventional 1.5 m2 shaft required for a natural-ventilation system as set out in Approved Document B.
The secret of the system is the patented OSLoop control system. This looped power and data system constantly monitors all inputs and outputs — including all cabling and the position of smoke vents in accordance with EN12101 Part 9. Intelligence in the system is the key to its effectiveness.
Should a fire occur, Shevtec smoke detectors in the corridor will determine which smoke shaft is closest to the fire and use that shaft to extract smoke. Both Shevtec smoke-shaft doors on the corridor will automatically open and the extract fan on the shaft will operate. The OSLoop system will ensure that all other smoke-shaft doors remain closed so that smoke shafts work efficiently and prevent smoke entering other corridors served by them.
In accordance with Approved Document B, the OSLoop system will automatically open the Shevtec louvre at the top of the staircase if the system is activated to ventilate any smoke that may enter the staircase as fire doors to the escape stair are opened.