Luca.mirtanini
Mechanical
- Sep 9, 2019
- 1
Hi all,
I am trying to master the design of a air supply system dedicated to a stairwell pressurization.
Usually (depending on the class of the building) there are different criteria that should be satisfied:
1. Airflow criterion (a velocity, e.g. 0,75 m/s, should be satisfied at the door of the plan where there is the fire)
2. Pressure difference criterion (a pressure difference, e.g. 10 Pa, should be satisfied with the last door open)
3. Pressure difference criterion-all door closed (a pressure difference ,e.g. 50 Pa, should be satisfied with alla the door closed)
The problem for me is which pressure and which flow rate should I consider when I size the fan? If I oversize the fan, is there the danger that the door cannot be opened?
Usually the most demanding flow rate is the one of the pressure difference criterion, while the most demanding pressure is the one of the Pressure difference criterion-all door closed.
On other thing that it is critical for me is the fact that if I size a pressure relief vent should I consider it in the flow rate calculation?
Best regards, thank you in advance
I am trying to master the design of a air supply system dedicated to a stairwell pressurization.
Usually (depending on the class of the building) there are different criteria that should be satisfied:
1. Airflow criterion (a velocity, e.g. 0,75 m/s, should be satisfied at the door of the plan where there is the fire)
2. Pressure difference criterion (a pressure difference, e.g. 10 Pa, should be satisfied with the last door open)
3. Pressure difference criterion-all door closed (a pressure difference ,e.g. 50 Pa, should be satisfied with alla the door closed)
The problem for me is which pressure and which flow rate should I consider when I size the fan? If I oversize the fan, is there the danger that the door cannot be opened?
Usually the most demanding flow rate is the one of the pressure difference criterion, while the most demanding pressure is the one of the Pressure difference criterion-all door closed.
On other thing that it is critical for me is the fact that if I size a pressure relief vent should I consider it in the flow rate calculation?
Best regards, thank you in advance