Protecting Means Of Escape The Shev Company CR140 Stirling Ventilator
We are only now, today, recognising what early man has known since the discovery of fire. Wind has an effect on fire and smoke and if you sat on the wrong side of the camp fire you got smoke in your eyes.
Whilst it has been talked about and even written about since the 1960’s and who knows before then, the effects of wind on smoke ventilation systems has been widely ignored, presumably on the basis of "It will be alright on the night."
It is now generally accepted that cross wind has significant affect on Natural smoke ventilation as cross wind batters exhausting smoke against open casements. Turbulence is caused hindering the rapid exhaust and dispersal of smoke and at worse actually forcing/scooping the smoke back through the ventilator
CIBSE fire engineering Guide E stresses the importance that vents be positioned where they will not be adversely affected by external wind conditions.
BS9999 too makes reference to smoke outlets not being located in positions likely to be subject to adverse wind effects and EN 12101 Part 2 goes someway further to addressing this situation by recognising side wind influence and that single flap ventilators should have a fire open position of 140 degrees to prevent the scoop effect caused when a single flap casement diverts wind flow down into the ventilator.
Specifically designed to prevent “wind scoop” caused by open casements deflecting wind down into the ventilator, the Stirling CR140 ventilator fulfils the requirements in EN12101 for roof mounted single flap ventilators to open a minimum of 140º within a 60 second period.
Now as the wind drives across the roof and encounters the 140 degree open casement The streamline open profile of the ventilator allows the escaping smoke to skate over the open casement unhindered allowing and even assisting the rapid exit of the smoke from the ventilator.
For more information visit www.shevcompany.co.uk or email us at admin@shevcompany.co.uk
© Copyright 2011 Means Of Escape Terms & Conditions Privacy Policy
Copyright © 2011 Think Agency - Website Designers Kent