16 April 2010
‘Asphyxiation’ can be due to inhaling carbon dioxide which takes the space of oxygen within our blood supply. ‘Chemical irritants’, such as sulphur dioxide, ammonia, hydrogen chloride and chlorine can cause the airways to swell and/or mucus to build up blocking the airway. ‘Chemical asphyxiation’ damages cells and stops the supply of oxygen to the body, carbon monoxide, hydrogen cyanide and hydrogen sulphide are often produced in fires.
It is known that the worst of these gasses produced in combustion is carbon monoxide.
With this in mind all our offices, places of work and dwellings must be adequately protected, but are they?
We know that all our buildings are well provided for as far as fire escape is concerned, this assumes that we have the time on hearing an alarm to adequately leave the building on foot through a fire protected route. Our perception is that the route should be free from a fire hazard, as many of us have never experienced a real fire, but do we consider that it will be smoke free?
Most of us have a false security about fire in buildings, we know we are relatively safe as there are designated routes and fire doors and, of course, each building is inspected by the respective fire authority. We are also protected by smoke detectors, which give us an early warning of smoke as an indication of a fire or something burning which we should be aware of and evacuate - again we tend to be misleading ourselves into a false security...
If we do encounter smoke, will it be relatively mild or harmless, fairly easy to see through, or could it be highly toxic and thick black, making it difficult to open our eyes let alone take a breath? Are we aware at the speed in which smoke can build up and block our means of escape? Caught in this difficult situation, panic quickly takes over. Obviously the toxicity of the smoke depends on what is burning and this is something we have no control over - or do we?
We can and do equip our new building with modern smoke ventilation control to ensure that not only are our routes to escape free from fire hazards, but also as free as possible from toxic fumes by allowing air into the building and allowing the hot gasses to escape at a higher level. The other important factor taken into consideration is the combustibility of materials. The recent fire at Shirley Towers, Southampton, where sadly two firemen lost their lives it is said due to a staircase and ceiling collapse, but as yet this is to be confirmed.
Remember up to 80% of deaths in building fires are caused by smoke inhalation.
New and refurbished buildings are now required to be designed and built to offer the latest in smoke ventilation technology, making new buildings in the UK some of the safest in the world. When a code compliant system is not a viable option for the building Computational Fluid Dynamics (CFD) can be used to model the effectiveness of a smoke control system. Buildings can be subject to ‘what if’ scenarios which simulate fires and the travel of smoke by installing smoke control systems, which automatically open doors, vents and windows in walls and roof areas, by designing smoke shafts, we can build safety into our new buildings. Once these systems are installed, they must be commissioned, tested and adjusted to ensure maximum protection. Together with regular maintenance and fire drills the system will protect inhabitants and employees as far as practicably possible.
This level of cover is designed into our latest buildings and refurbished buildings, but what about the older buildings we currently have? The UK has some of the oldest building stock in the world and whilst it is mandatory to have a means of escape in fire, not all these buildings are adequately protected for smoke ventilation.
Fortunately for inhabitants and employees, the onus of responsibility is now falling on the building owner and as insurance premiums rise, the liability is placed squarely at their doorstep and our older buildings are receiving much needed protection.
We have been considering the potential loss of life in a fire, the secondary cost of smoke damage should also be considered for building owners. As a building owner, designer or developer who should we approach to ensure that our buildings are as safe as we can currently make them in the unlikely event of a fire?
Specialist companies do exist which can offer solutions to meet the relevant standards - one company, which has over 27 years experience of offering a complete service, is SE Controls based in Lichfield. SE Controls cover the whole of the UK and Ireland, with new build, refurbishment and existing buildings all falling within their broad experience of smoke ventilation design. The company can offer a one stop solution from initial survey through to on-going maintenance of systems.
SE Controls has developed SHEVTEC® to offer a complete solution which complies with building regulations and fire engineering requirements. When introduced early on in the design stages, SHEVTEC® can help specifiers provide the most cost efficient, practical and compliant design for smoke ventilation.
For information on the principles, strategies and products view http://www.secontrols.com/introduction/smoke-ventilation/residential/ Go back