New regulations in NFPA 92 regarding number of doorsdesigned to open in pressurized stairwells

This paper briefly reviews the origin of the issue regarding the determination of the number of open doors in the design calculation of stairwell pressurization air supply systems. The new regulations of NFPA 92-2021 regarding the number of open doors in pressurized stairwells and the background of their formulation are presented. It is believed that significant breakthroughs and progress have been made in the stairwell pressurization air supply technology, which deserves attention, systematic research and reference.