BMS and Pressure Differentials

Hello All,
I was wondering if you could clear something up for me please.
As part of our qualification of the facility, we measure particle counts, room recoveries, air supply velocity and volume, noise and light levels and pressure differentials between rooms (its an ISO class 5 environment).

Our building management system continuously monitors the pressure differentials and alarms if it goes out of spec.

My question therefore is, are we wasting time and effort measuring the room pressure differentials manuallly with a micromanometer as part of the bienniel requalification, when the BMS monitors it all year anyway?

Many thanks for your help guys,


Dear Newbie,

if the BMS is qualified and the differential pressure sensors calibrated, I see no need to measure manually the differential pressure during the requalification. In the requalification I would include the records of the differential pressures for the past (biannual, in your case) period, together with a trend analysis.

Best regards


I agree. It seems a real waste of time to duplicate. Why should one use a hand held if there is an approved and existing method of collecting the required data. Just make sure that you attach all the relevant data to the protocol such as calibration certificates for the pressure transducers, etc

Hope this is of some help.

Dear all,
If your BMS is qualified and monitoring is occured in routine then no need to do so? and having good evidence and trend.


If BMS qualified then same data can be used. Incase any excersions pl keep support documents ready to justify along with risk assesment if any. this will be more authentic than manual recording

New dimension !!

For facility qualification manual differential pressure monitoring may be avoided…based on the qualified BMS system…as an additional measure it can be retained as a part of BMS monitoring system re-qualification program.

Opinions …

I agree, it would its a waste of time - make sure youre sensors gets calibrated annually and keep an OOS record on your’e BMS system.