On Smoke Control by Pressurization in
Stairwells and Elevator Shafts

Dr. Richard S. Miller & Dr. Don Beasley
Department of Mechanical Engineering
Clemson University – August 8, 2008

To download the entire study, click here.

The primary findings of the study are:

• Stairwell pressurization is confirmed to be a viable means of preventing smoke entry into stairwells when used without elevator shaft pressurization.
• Elevator shaft pressurization is shown to be very different, and substantially more complex, than stairwell pressurization due to the much larger leakages areas around, and multiple numbers of, elevator doors.
• Elevator shaft pressurization results in pressure differences across elevator doors substantially in excess of 0.4 inches water if the system is to be used with the exterior doors in the closed position.
• Elevator shaft pressurization adversely a affects the performance of the stairwell pressurization system. If used in conjunction, the stairwell system requires substantially larger fan flow rates, and will exhibit excessively large pressure differences across stairwell doors if the systems are operated with the exterior building doors in the closed position.
• Both elevator and stairwell pressurization are independent of the pressurization source location and are unaffected by the use of louvers or vents if the pressure difference minimum is to be maintained.

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