Trane Engineered Smoke Control System, Application Manual

Page: 15 / 156

Methods of smoke control
BAS-APG001-EN 3
Figure 1: Sample pressure difference across a barrier
Table 1 provides the National Fire Protection Association (NFPA)
recommended minimum pressure difference between the high-pressure
side and the low-pressure side.
Table 1: Recommended minimum pressure difference
Table 2 on page 4 provides the NFPA recommended maximum allowable
pressure difference across doors. The listed pressure differences take into
account the door closer force and door width.
Building type
Ceiling height
(ft [m])
Minimum pressure
difference
(In.w.c. [Pa])
Sprinklered Any 0.05 (12.4)
Non-sprinklered 9 (2.7) 0.10 (24.9)
Non-sprinklered 15 (4.6) 0.14 (34.8)
Non-sprinklered 21 (6.4) 0.18 (44.8)
Notes:
•
The minimum pressure difference column provides the pressure
difference between the high pressure side and the low-pressure side.
•
The minimum pressure difference values incorporate the pressure
induced by the buoyancy of hot smoke.
•
A smoke control system should maintain the minimum pressure
differences regardless of stack effect and wind.
•
The minimum pressure difference values are based on
recommendations in NFPA 92A (NFPA 2000,
Recommended Practice
for Smoke Control Systems ).
• In.w.c. is inches of water column.
•
Pa is Pascals.