Protected escape routes designed to BS EN 12101-6 and BS 5588
BS EN 12101-6 provides for the pressurisation of protected escape routes from multi storey buildings. Pressurisation is achieved by pumping large volumes of air into the escape stairs and lobbies, which prevents smoke and heat entering them whilst people escape.
However while all doors remain closed it is necessary to control the pressure to enable people to open doors into the escape staircases. This is achieved by Air Pressure Control Valves set to operate at between 50 & 60 Pa to prevent doors becoming too heavy to open due to the pressure on them, thus enabling egress by everyone, including children and old people.
Air Pressure Control Valves are set to close below 50 Pa to divert air across the open doors to blow smoke back into the area where it is produced to give door protection.
It is normal to size the supply fan to protect to protect two open doors at 2.0 m3/s velocity plus an allowance for closed door leakage and 25% for fabric leakage. (In some circumstances the door protection velocity can be reduced to 0.75 m/s. The appropriate figure should be agreed with the District Surveyor prior to commencing design.)
This typically leads to large supply volumes being required - often in the region of 10.5 - 11 m3/s. Use Aercon Type T or Z valves, sized from our charts. Where Aercon valves are to be installed on external walls, weather louvres should be fitted to prevent ingress of rain and wind and the pressure drop across the louvre should be subtracted from the valve set pressure to give the correct overall pressure drop.