Dear all
Right now I’m doing the qualification of cleanroom. the problem is, in some room, i can’t get minimum of ACH. FYI, the pressure in this room is the lowest, so it gets the air from another room. can we measuring the air flow from the return grill? because when i measured it from the HEPA, the ACH is so low.
I’m sorry for my English. Thanks to all
You must measure the total supplied air in each room in order to calculate the air changes per hour (ACH= Total supplied air / Volume of room)
If the required supplied air is not enough, you must increase it!
You have to measure the total supplied air in eah room in order to calculate the air changes per hour. (ACH = Total supplied air / Room Volume).
If the required ACH is not achieved, you should increase the supplied air.
[quote=clevair]You have to measure the total supplied air in eah room in order to calculate the air changes per hour. (ACH = Total supplied air / Room Volume).
If the required ACH is not achieved, you should increase the supplied air.[/quote]
Clevair, thank you for yor answer
so there is no method for measuring from the return air grill? even in the lowest pressure room where it gets the air from another room too?
where can i get the reference about it, so i can strengthening my opinion?
Tk
Clevair, thank you for yor answer
so there is no method for measuring from the return air grill? even in the lowest pressure room where it gets the air from another room too? what is the idea so we have to measure it from the supply air?
where can i get the reference about it, so i can strengthening my opinion?
Tk
Hi Brian, U juste have to reach to lowest limit without to taken in account the highest one. Pressure cascade has only to be respected. Continue in french if necessary. regards, Cdt
[quote=brianalfredo14]Clevair, thank you for yor answer
so there is no method for measuring from the return air grill? even in the lowest pressure room where it gets the air from another room too? what is the idea so we have to measure it from the supply air?
where can i get the reference about it, so i can strengthening my opinion?
Tk[/quote]
ISO-14644-3 sections B.4.2-3
Measurement of supply airflow velocity only is required to calculate ACH.
Assuming you’re meeting you pressure cascade and particle counts. Why are you so concerned about ACH?