Mat, The problem is similar to maintaining a clean room with positive air pressure to keep airbourne particles out. The key is to maintain the smoking room at negitive air pressure differential versus the surrounding canteen. That means pumping more air INTO the canteen (from outside the building or from other areas of the building or some combination of both) than is exhausted from the smoking room (which should be exhausted to outside the building with no additional air (or makeup air) pumped into that room). The result is to pump air into the canteen from somewhere else, overflow into the smoke room and then exhaust outside. This will keep the smoke from exiting the smoke room except through the exhaust to the outside. If the differential is small, some smoke filled air will be dragged by bodies exiting the smoke room into the canteen. If the differential is significant, a small vent, low in the smoke room door will allow more fresh air from the canteen to enter the smoke room for subsequent exhaust. You do not mention if the 16" fans are in duct work moving air from one area (or room) to another and if so in which direction OR free standing, moving air around within the same area which would only add turbulence and do nothing for ventilation. Good Luck Bruce Misner > ---------- > From: Matthew > Lamkin[SMTP:[log in to unmask]] > Reply To: TechNet E-Mail Forum.;Matthew Lamkin > Sent: Thursday, August 17, 2000 10:46 AM > To: [log in to unmask] > Subject: [TN] Any ventilation experts out there? > > Hiya folks, > I know that this is a bit off topic, but are there any ventilation > experts out there? > > If I explain why I ask: > My employers stopped smoking on the premises a while ago, but knocked up > a partitioned room in the canteen > for the die hard smokers to use (rather that than lose them). > However the canteen quickly fills with smoke, making it unbearable to > non smokers. > > The canteen is approx. 70' long X 20' wide X 10' high, ate each end is a > 16" (approx.) fan. > The partitioned smoker room is an enclosed room with a small 9" fan in > it > (its all that would fit in the roofspace available as its next to some > windows). > > What happens is that "the smokers" come and have a smoke, filling the > room and the smoke just happens to > leach out as the fan in there is inadequate to extract it. > The fans at either end keep getting messed with as everyone seems to > have their own opinion as to how best to operate them. > So when it comes time for me to go and eat my dinner, the air is stale & > bad to breath, I then have to open the windows & everyone complains of > getting cold etc. > > If there is an expert out there could I beg a suggestion as to the best > way to operate the fans? > (I know the "best" thing is to get rid of the smoke room, but that's not > going to happen for a long while). > > > Here is a rough ASCII drawing of the room. > _______________________________________________ > | |--| | SMOKE > | |--| | > | FAN1 | ROOM | > FAN2 | > | |________________| > | > | > | > | > | | > |____________________________________|__________| > 7' HIGH WOODEN > PARTITION > > Many thanks for any reply... > Matthew Lamkin > PCB Draughtsman. > > ############################################################## > TechNet Mail List provided as a free service by IPC using LISTSERV 1.8c > ############################################################## > To subscribe/unsubscribe, send a message to [log in to unmask] with > following text in > the body: > To subscribe: SUBSCRIBE TECHNET <your full name> > To unsubscribe: SIGNOFF TECHNET > ############################################################## > Please visit IPC web site (http://www.ipc.org/html/forum.htm) for > additional > information. > If you need assistance - contact Keach Sasamori at [log in to unmask] or > 847-509-9700 ext.5315 > ############################################################## > ############################################################## TechNet Mail List provided as a free service by IPC using LISTSERV 1.8c ############################################################## To subscribe/unsubscribe, send a message to [log in to unmask] with following text in the body: To subscribe: SUBSCRIBE TECHNET <your full name> To unsubscribe: SIGNOFF TECHNET ############################################################## Please visit IPC web site (http://www.ipc.org/html/forum.htm) for additional information. If you need assistance - contact Keach Sasamori at [log in to unmask] or 847-509-9700 ext.5315 ##############################################################