0:27 - - Mechanical smoke ventilation systems are designed to (1) *protect escape routes* (corridor + staircase), + (2) aid fire fighting. 0:37 - - these systems have advantages over a natural smoke-venting system - as they (1) *remove smoke rapidly* + (2) *remain unaffected by wind conditions.* 0:46 - - the systems comprise of a (1) *mechanical extract shaft that serves the common corridor* (+/or lobby) - with the replacement air generally provided from the (2) stairs - - by means of a (3) *pressure-controlled door closer;* 1:02 - - this (1) *de-pressurizes the stairs* - (2) allowing for a large quantity of fresh air to be pulled through the (corridor +/or) lobby, + (3) preventing smoke-flow into the stairwell. 1:38 - - *Example of how system works* (clears hall in about 12 seconds)
The smoke is usually worse than the fire... if it takes a while for the fire fighters to get to someone it won’t matter if they suffocate from smoke inhalation
0:27 - - Mechanical smoke ventilation systems are designed to (1) *protect escape routes* (corridor + staircase), + (2) aid fire fighting.
0:37 - - these systems have advantages over a natural smoke-venting system - as they (1) *remove smoke rapidly* + (2) *remain unaffected by wind conditions.*
0:46 - - the systems comprise of a (1) *mechanical extract shaft that serves the common corridor* (+/or lobby) - with the replacement air generally provided from the (2) stairs - - by means of a (3) *pressure-controlled door closer;*
1:02 - - this (1) *de-pressurizes the stairs* - (2) allowing for a large quantity of fresh air to be pulled through the (corridor +/or) lobby, + (3) preventing smoke-flow into the stairwell.
1:38 - - *Example of how system works* (clears hall in about 12 seconds)
how does it goes with NFPA ?
if they will not accept it it is irrelevant , where is a specific code for this ?
The snag is that they increase the rate of combustion drawing fresh air in to fuel the fire
The smoke is usually worse than the fire... if it takes a while for the fire fighters to get to someone it won’t matter if they suffocate from smoke inhalation