How to Calculate Air Flow for Maintaining Room Pressure Differential?

Click For Summary

Discussion Overview

The discussion focuses on calculating the airflow required to maintain a pressure differential of 30 Pa between a room and the outside environment. It encompasses theoretical approaches, practical considerations, and references to standards related to airflow and pressure differentials.

Discussion Character

  • Technical explanation
  • Experimental/applied
  • Debate/contested

Main Points Raised

  • One participant seeks a formula to calculate the airflow needed to maintain a specific pressure differential.
  • Another participant suggests using the formula Q = 0.83AP^-n, with variables defined for net flow rate, effective area of leakage, differential pressure, and a variable n that ranges from 1 to 2 based on the type of openings.
  • Concerns are raised about the difficulty of estimating leakage, with a suggestion that experimental methods may be necessary.
  • A reference to construction standards is made, indicating that they provide approximate measurements for leakage areas based on construction quality, specifically mentioning British Standard BS EN 12101-6:2005.
  • A request for more details about the EN 12101-6:2005 standard is made by a participant.
  • Another participant provides a brief description of the EN 12101-6:2005 standard, noting its focus on pressure differential systems designed to prevent smoke from entering critical spaces during a fire.
  • A correction is made regarding the wording of the description of the standard, emphasizing the specification aspect.

Areas of Agreement / Disagreement

Participants express varying views on the methods for estimating airflow and leakage, with no consensus on a single approach or formula. The discussion remains unresolved regarding the best practices for calculating airflow and the applicability of the referenced standard.

Contextual Notes

Participants highlight the challenges in estimating leakage and the dependence on specific construction standards, indicating that the discussion may be limited by the assumptions made about the room's construction and the accuracy of the proposed formulas.

enmuaxuan
Messages
2
Reaction score
0
I have a room 6x6x3 m
I want to maintain the Difference pressure between the room and outside area 30Pa.
How can i calculate the rate of supply and exhaust air flow to do it?
is there a formula to calculate?
Pls help me.

Thanks in advance
 
Engineering news on Phys.org
Use Q = 0.83AP^-n, where Q = net flow rate, A = effective area of leakage, P = differential pressure, and n = 1 to 2 (1.6 for cracks around windows, 2 for large openings such as doors and windows).
 
Estimating leakage is extremely difficult. You may need to do it experimentally.
 
construction standards may also be used as a reference. they have an approximate measurement on leakage areas based on the type or quality of construction of the building, or room for the case of enmuaxuan. try british standards, specifically BS EN 12101-6:2005. the equation i have given you is also found there.
 
Thanks.
Mervincris, could you give the detail of EN 12101-6:2005?
Thank you again.
enmuaxuan
 
no prob. it is specifies the standard for pressure differential systems to prevent the smoke, during fire, from entering critical spaces. usually, these critical spaces are stairwells which are used as means of escape during fire.
 
mervincris said:
no prob. it is specifies the standard for pressure differential systems to prevent the smoke, during fire, from entering critical spaces. usually, these critical spaces are stairwells which are used as means of escape during fire.

correction: ...it specifies...
 

Similar threads

Replies
1
Views
1K
  • · Replies 38 ·
2
Replies
38
Views
4K
  • · Replies 4 ·
Replies
4
Views
4K
Replies
3
Views
2K
  • · Replies 3 ·
Replies
3
Views
3K
  • · Replies 20 ·
Replies
20
Views
4K
  • · Replies 9 ·
Replies
9
Views
2K
  • · Replies 4 ·
Replies
4
Views
3K
  • · Replies 6 ·
Replies
6
Views
3K
Replies
0
Views
2K