nuuvox000
Mechanical
- Sep 17, 2019
- 344
I've just read through the ASHRAE laboratory design guide but I'm still a little confused about pressurization techniques for laboratories. I have two fume hoods which will exhaust air so I believe I need to supply makeup air while they are running. But I also need to keep the laboratory space at a negative pressure with respect to surrounding spaces. The dilemma as I see it is that I will have to introduce makeup air for the exhaust hoods but this means I still need to have general exhaust to keep the space negative. But if I keep the space negative, don't I risk pulling fumes out of the exhaust hoods?
My other question is on air leakage area (sq in/100 sqft). Have any of you had experience using certain values? ASHRAE says it can vary from about 2 to 30 sq in per 100 sqft of surface area. Based on the study they referenced, I'm using about 20 (non-gasketed ceiling tiles, one door, two windows, 155 sq ft room).
I'm just starting out so thanks for your patience. Thanks in advance!
My other question is on air leakage area (sq in/100 sqft). Have any of you had experience using certain values? ASHRAE says it can vary from about 2 to 30 sq in per 100 sqft of surface area. Based on the study they referenced, I'm using about 20 (non-gasketed ceiling tiles, one door, two windows, 155 sq ft room).
I'm just starting out so thanks for your patience. Thanks in advance!