Clean Room Pressure Differential 1

[friartuck]

Can anyone tell me if there is a standard pressure differential requirement for clean spaces. I work on 15Pa with an alarm setting of 10Pa.

One of our clients insists that it is 15Pa minimum (i.e. alarm status) so we need to control/aim for to 20Pa.

I think anything over 20Pa would make the doors hard to open anyway, so the norm is 15 with a 10 alarm status.

Any one got any documentational evidence that the client is right?????

PS the job is the pharmaceutical production of tablets etc.

Friar Tuck of Sherwood

 

[HEC]

Friar,
I have generally used 15Pa as the design DP for segregation of clean rooms. Yes the higher DP will make opening of swinging PA doors harder, the main problem may be in keeping them closed! As in all things the customer is always right, sometimes missguided, but right! Do teh design fort he higher DP but allow for it to be lowered during commissioning when doors swing violently or trap people in the rooms!
Good Luck

Mark Hutton

 

[quark]

Documental and experimental evidence is for 0.05"wc or 12.5Pa (I recommend article Room Pressure dated Feb'2003 from ASHRAE Journal. However, for pharmaceutical clean rooms, the PD is minimum 15Pa if the classification of the two rooms is different. Otherwise, it can be 10Pa.

My experience is that, for a 1.8mW x 2.1m H doors, you can go upto 30Pa without problems. Beyond that we require extra push.

 

[lilliput1]

Make sure you lock out the alarm while the door is open or you will get nuisance alarms.

 

[HVAC68]

It's not only the doors. If I am correct, the higher pressure differential you require, the more attention you need to give to the walls, roof, floor, etc., to reduce inflitration/exfiltration through "cracks".

HVAC68