- #1

Ioannis

- 2

- 0

I am trying to calculate the openings of a sealed room according to a pressure drop in a specific time.

I have the following equation:

Q = 840*A*√(dP)

Q: differential airflow in liters/sec

A: room leakage in m

^{2}

dP: differential pressure in Pa

So, if for example we have a room of 500m

^{3}at atmospheric pressure 101325 Pa and we increase its pressure** by 80 Pa and then measure how much time it will need to decrease for 30Pa we can calculate the differential airflow by the following:

(P

_{si}+ P

_{start}) * V

_{1}= (P

_{si}+ P

_{finish}) * V

_{2}<=>

(101325+80) * V

_{1}= (101325+50) * V

_{2}<=>

V2 = 500.148m

^{3}

So because of a dP of 30Pa we get 148 liters difference.

If that dP occurred in 180sec then we get Q= 148/180 = 0.82 liters/sec

If we then put this number to the initial equation we get the room leakage.

My problem is that the results that I get are different from another method that is used to find the room leakage. So obviously there is a mistake in the above calculations but I can't find what.

**The pressure increase of the room is achieved by using a blower and the temperature is stable.

Does anyone have an idea?

Thank you in advance!