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well it is a very long answer i'll describe it briefly then you have to search for more
- there are tow ways1- British standers 2- ASHREA standers
- in my work i prefer to use British it is easy simple and clear
- reference BS EN1-6
- choose the classification of the building from (table1)
- use (table A.3) to find out the air leakage
- as an example we will take class D system :
1. pressure difference criterion mode
- indicate no. of door and types
- calculate air leakage area as per table a.3 , pressure differential pa (all the doors are closed)
- Apply a safety factor of%
2. escape mood:
A.Velocity Criterion– (for one open door at fire floor & other at exit door
- Velocity =0. m/s , Q = V X Adoor
* Total air flow = pressure difference mode + velocity criterion mode
- adding% as a duct leakage ------->
a. B. Pressure Criterion– (for one open door at fire floor & other at exit door):
n pressure = Pa
use this equation Qd=0. x Ad x P^1/2
* Total air flow = pressure difference mode + pressure criterion mode
- adding% as a duct leakage ------->
select the higher value from & #
- this way is almost the same for other classes may you found a little changes for no. of doors open or velocity , pressure value , so you have to check BS EN1-6 for complete image
Eng. Shareef , please add an example to explain this method ,
thank you
