Venting - small quantity of gaz in a large room

Posted in: , on 26. Jul. 2007 - 17:06


I want to calculate a venting surface in case of a small quantity of heavy gaz, in a large room.

I know that NFPA 68 v2007 allows this calculation for dust explosions, but there is no precision for gas explosions.

thank's a lot for any idea,


Cold Gas

Posted on 27. Jul. 2007 - 03:47

Hi marien69

The most common text for that is the American Society of Industrial Health, but most Fire Departments can put you on the right track.

Some gas floats, other sinks. You want to suck from the bottom to drag away the heavy gases. They are usually calculated on the basis of so many changes per hour of make-up air. Take the volume of pollutant generated, check what are acceptable concentration levels, and voila - you have a rule-of-thumb formula. Stock standard stuff on Eng-Tips Forum, or ASHRAE Guide on Ventilation.

Regards - Sgt John.Rz / Open Book Club / Files / Bionic Research Institute