ppv new technique?
im looking for any information on the new positive pressure vent technique that involves only covering about 80% of the opening with the air flow of the ppv fan(although I was always taught 100% coverage was a must). This technique will tell you if the opening on the other side of the structure does not allow for a complete vent, by smoke kicking back out the main venting door as only 80% is covered by the fan. My understanding is that if the opening on the opposite side of the structure which smoke is being forced toward is not large enough, this will cause the smoke to cycle back through the structure creating almost like a convection type atmosphere. Any input on this or further knowledge would be great...thanks