What is the maximum allowable pressure for a latch on an emergency egress door?

What is the maximum allowable pressure for a latch on an emergency egress door?

• A. 8 psf
• B. 15 psf
• C. 12 psf
• D. 18 psf

Answer: (B)

The key idea is that emergency egress door hardware must remain operable even when there is air pressure pushing on the door from one side, such as during a fire or ventilation scenario. The latch is rated to release and the door to open up to a certain differential pressure; this ensures occupants can exit quickly without being blocked by the door. 15 psf is the maximum differential pressure that the latch and associated hardware are designed to handle while still allowing the door to open readily. This value provides a practical balance: it’s high enough to account for realistic pressure differences in a building under emergency conditions, but not so high that it would require unnecessarily heavy or expensive hardware. If a building could experience greater differential pressures, higher-rated hardware would be selected.

The key idea is that emergency egress door hardware must remain operable even when there is air pressure pushing on the door from one side, such as during a fire or ventilation scenario. The latch is rated to release and the door to open up to a certain differential pressure; this ensures occupants can exit quickly without being blocked by the door.

15 psf is the maximum differential pressure that the latch and associated hardware are designed to handle while still allowing the door to open readily. This value provides a practical balance: it’s high enough to account for realistic pressure differences in a building under emergency conditions, but not so high that it would require unnecessarily heavy or expensive hardware. If a building could experience greater differential pressures, higher-rated hardware would be selected.