A stairwell smoke ventilator is an automatic opening ventilator (AOV) which provides at least 1.0m2 of free area when open. It usually serves one of two purposes;
‘Smoke shaft’ is the common term for ventilation systems in the lobbies of tall buildings, used to maintain tenable conditions in the common escape routes in the event of a fire in the building.
They are essentially a simple ventilation system designed to extract any smoke leaking into a common lobby to protect the escape stairs. Typically, a vertical builder’s work duct rising through the building would be used to extract smoke from the lobbies. Each lobby would have a damper connected to the builder’s work duct.
If a fire breaks out, which results in smoke getting into communal lobbies or corridors adjoining the escape stairwell, there needs to be some means of removing smoke from these areas. Solutions to this include the installation of an automatic opening ventilator (AOV) or a natural/mechanical smoke shaft system. As smoke is extracted through such a system, the stairwell ventilator provides replacement air to allow people to escape safely and firefighters to enter the building easily to tackle the fire.
The ventilation of car parks is important to prevent the build-up of toxic fumes and flammable gases from motor exhausts, and to clear smoke in the event of a fire. The Building Regulations (in particular Approved Document B and Approved Document F) specify what is required to maintain safe conditions in a car park. Further guidance is also given in BS 7346-7:2006.
After deciding the flow/extract rate and the size of the mechanical smoke shaft you’ll now have all the variables required to select the fan needed to extract smoke from the fire zone. It is usual to provide run and standby fans which are typically rated at 300 0C for 1 hour. They tend to be mounted in series on the roof with flexible connections and anti-vibration mounts along with back draught dampers to prevent cold air being drawn into the building. A duct resistance should be completed for the installation once the design has been fixed.
When you have decided on your flow/extract rate, the next step is to decide on the size of the builder’s work shaft that is needed to transport the smoke to the external atmosphere.
Situated in the trendy and bustling Czar Peter district of Amsterdam, the former primary school on Blankenstraat, has been imaginatively yet sensitively converted into an impressive mixed-use building housing loft apartments and offices. Urban roof terraces offer the apartment residents fabulous views over the city and were made possible through the installation of Glazing Visions Skydoor rooflights which use Easivent's folding arm actuators.
Inverter drives (also known as variable speed drives or VSDs) are commonly used in smoke control applications to limit and modulate fan speed to suit a particular system design.