mportant aspects addressed in NFPA 496 are:
Design
The number of people in the pressurized control room should be controlled so as to not throw off the pressurization.
The design of this room should ideally have as few doors as possible, as this can alter the room/enclosure’s overall pressurization rates.
The volume of air introduced to the environment must be proportionate to the needs of the HVAC equipment and other electrical equipment.