MECHANICAL SMOKE VENTILATION
Mechanical Smoke Ventilation System (MSVS) is an industry approved method to quickly clear smoke from protected lobbies and staircases.
MSVS is an alternative method of smoke ventilation as detailed in Approved Document B, BS9991:2015 and BS EN 12101.6
To ensure the “alternative method” is compliant, Dyer recommend that MSVS is substantiated by a design report and calculation using Computational Fluid Dynamic (CFD).
Dyer supply, install and commission mechanical smoke ventilation systems that are fully compliant with the detailed recommendations on the design of such systems in line with the Smoke Control Association’s publication – Guidance on Smoke Control to Common Escape Routes in Apartment Buildings.
MSVS is designed to provide mechanical extract of smoke laden air and natural or replacement air inlet. Detection of smoke within the protected lobby will automatically trigger the system. The fire damper will open into the smoke shaft, other dampers are then “locked out” to ensure they stay closed. A fan set compromising duty and standby smoke ventilation fans is installed on the roof, the duty fan will operate to draw smoke through the damper and up the shaft. If this fan fails, an automatic transfer switch will operate the standby fan.
Inlet air is provided by opening a Natural Heat Smoke Exhaust Ventilator (NSHEV) at the head of the protected staircase. Fresh air is drawn through the staircase and door into the protected lobby.
This keeps the staircase free of smoke to allow safe escape for residents and safe access for firefighters. The basic principle of operation is similar for different building configurations, control of the system is adaptable to meet the architects design