Value for money and carpark head height were key considerations. Concept for already existing stair pressurisation was challenging; air discharge went straight out egress door, meaning door pressures in lower levels were unlikely.
The AC concept was simplified and used a performance approach to achieve ventilation. To get the existing stair pressurisation to work, we had to create a strong negative pressure in the carpark. This was achieved by controlling the roller door and modifying the carpark supply ventilation so that it could operate in reverse in fire mode.
