Reliability - Smoke Control Systems

[Guest]

It appears that smoke extract systems are being used in FSE strategies to enable longer travel distances, larger compartments etc. According to the new BS 7974-pt 7 they have a 90 or 95% reliability, ie work on demand. There is no research to back this up, how do they arrive at this figure. To be honest I lack confidence in them. :cry:

[Guest]

They guessed, I guess, like they always do. As the only way of getting statistics is from industry (the companies who produce them). They will not give you confidential information.
Great example, the nuclear safety document produced in the states for individual parts of nuclear systems. The stats came from the government. So, as everyone uses this document which is based on statistics by the US Government from during the cold war, on nuclear safety systems, would you a) tell the truth, or b) lie about how good your systems were to make the russians scared? Hmm, let me think. Hence, the stats whic you reference could be either worse than that, but, as most systems fail safe, they are likely to be far better than stated.

[ian 2243]

It appears that smoke extract systems are being used in FSE strategies to enable longer travel distances, larger compartments etc. According to the new BS 7974-pt 7 they have a 90 or 95% reliability, ie work on demand. There is no research to back this up, how do they arrive at this figure. To be honest I lack confidence in them. :cry:

You do not say why you lack confidence in them, if as you say there is no research how can you then come to this conclusion?
Smoke control/extract systems are extensively tested or there wouldn't be a BS.
I have seen them working and for the most part they are effective in controlling the height of the smoke layer and as a consequence the thermal output of the fire. Look through past incidents involving large shopping centres and you will see the effectiveness.
Fire Brigades use defensive and offensive ventilation depending on the nature of the fire as more emphasis is placed on smoke control in the dynamic risk assessment.

Ian.