Three stair pressurisation systems with overpressure relief features have been tested in a 22-storey apartment building and in two high-rise office buildings. Specifically, exit door relief, barometric damper relief, and a feedback control with a variable-pitch blade supply air fan were subjected to open-door tests. The pressure differences across the stair doors and air velocities at the stair door opening were measured.

KEYWORDS: site testing, pressurised stairs, multistorey buildings, flats, offices, doors, pressure difference, pressure relief devices, measuring, dampers, controls, stairs.