Smoke Ventilation In large open spaced buildings, carparks, shopping enters, exibition halls etc, the usual method ofsmoke control is by ventilation - extractingthe smoke from the area.Major development work on Axial Flow Fansfor the venting of hot fire smoke was carriedout during the 1980's (Ref 4), which led tothe publication in 1990 of a test standardBS7346 Part 2 (Ref 5).In high rise, multi room buildings, where theStaircases, Lift Lobbies and Corridors providethe escape route, smoke extraction may only serve to worsenthe situation.A smoke extraction system, illustratedin Fig 1, will provide negative pressure in theescape routes which will tend to draw thesmoke into the very spaces requiring protection.