As per NFPA 92 Annex F Clause F.4 (Compensated Systems –Overpressure Relief) allows discharging the staircase overpressure into the building subject to the following conditions:
1. the effects on the integrity of the stairwells and the interaction with other building HVAC systems should be closely studied;
2. Systems using this principle should have combination fire/ smoke dampers in the stairwell wall penetrations.
In my case,
1. In case of fire, the HVAC system is switched off and therefore there is no interaction between the HVAC system and the over pressure relief system; and
2. Combined fire – smoke dampers are used to discharge the over-pressure into the building.
How to achieve the integrity of the stairwells where the Combined fire – smoke dampers (Used as PRD) are located on the wall and opened during the fire event, and how to show the effects on the integrity of the stairwells during this scenarios.