Smoke control system for atrium
Smoke control system for atrium
(OP)
I've just been handed a task of calculating and designing the smoke control system for an atrium.
The project is a 9 story (occupied) hospital in Atlantic City, NJ with a mech/elect penthouse and heliport directly above that.
The atrium in question is 3-stories in height with the opening larger in size as you go vertical. The opening is skewed also, shewed rectangular in shape actually.
The code enforced is IBC 2000 New Jersey Edition.
Just about 3 hours reading thru multiple times, this appears very complicated (i.e "bag of worms") for an introduction. Analysis has to take into account stack effect and wind effect and given formulae for certain criteria.
Even the design fire has engineering analysis factors to be considered such as fuel, fuel load, steady and unsteady fire. They give you a design fire rate of 5000 btu/sec but this does not include those factors. In fact, I do not see the factors in a formula so that's a question I have.
Any professionals here have experience in this area?
The project is a 9 story (occupied) hospital in Atlantic City, NJ with a mech/elect penthouse and heliport directly above that.
The atrium in question is 3-stories in height with the opening larger in size as you go vertical. The opening is skewed also, shewed rectangular in shape actually.
The code enforced is IBC 2000 New Jersey Edition.
Just about 3 hours reading thru multiple times, this appears very complicated (i.e "bag of worms") for an introduction. Analysis has to take into account stack effect and wind effect and given formulae for certain criteria.
Even the design fire has engineering analysis factors to be considered such as fuel, fuel load, steady and unsteady fire. They give you a design fire rate of 5000 btu/sec but this does not include those factors. In fact, I do not see the factors in a formula so that's a question I have.
Any professionals here have experience in this area?





RE: Smoke control system for atrium
RE: Smoke control system for atrium
Another easier way to handle this would be talk to companies like "Colt" or any other company who specialise in smoke ventilators. They have inhosue softwares to do these calculations.
HVAC68
RE: Smoke control system for atrium
Anyway, P184 of IBC 909.9.2 has an equation with a factor q'' "Incident radiant heat flux for non-piloted ignition in btu/ftsec"
Anybody know that factor?
RE: Smoke control system for atrium
RE: Smoke control system for atrium
RE: Smoke control system for atrium
RE: Smoke control system for atrium
Its back to 2000 IBC per the Architect
The atrium is triangular in shape with balconies. The only open space clear to the top is in the one corner because there is a stair going from the 1st to 2nd floor smack dab in the middle of the opening. The opening is a skewed rectangular shape and increases in size as you go vertically.
I calculated an axisymmetric plume in the vertical clear area vertically and the design plume does not contact the walls as you go vertically. Plume expands vertically. The cfm is around 170,000.
I also ran some balcony spill plume calculations for each floor and the worst case is on the order of 600,000 cfm based upon a fire occuring at the one of the exit openings (worst case horizontally from the vertical opening). Or should the balcony spill plume calculations be based upon a design fire located at a fixed piece of fuel such as a chair or operator's desk within the space?
RE: Smoke control system for atrium
RE: Smoke control system for atrium
That is with the design fire of 5000 btu/sec. That's 18,000 mbh! I'd have to see if the code official will let us use a rational analysis of a fire.