707.14.2.1 Pressurization requirements. Elevator hoistways
shall be pressurized to maintain a minimum positive pressure
of 0.04 inches of water column and a maximum positive pressure
of 0.06 inches of water column with respect to adjacent
occupied space on all floors. This pressure shall be measured
at the midpoint of each hoistway door, with all ground floor
level hoistway doors open and all other hoistway doors closed.
The supply air intake shall be from an outside, uncontaminated
source located a minimum distance of 20 feet (6096 mm) from
any air exhaust system or outlet.
707.14.2.2 Ducts for system. Any duct system that is
part of the pressurization system shall be protected with
the same fire-resistance rating as required for the elevator
shaft enclosure.
707.14.2.3
Fan system. The fan system provided for the pressurization
system shall be as required by this section.
707.14.2.3.1 Fire resistance. When located within
the building, the fan system that provides the pressurization
shall be protected with the same fire-resistance rating
required for the elevator shaft enclosure.
707.14.2.3.2 Smoke detection. The fan system shall
be equipped with a smoke detector that will automatically
shut down the fan system when smoke is detected within
the system.
707.14.2.3.3 Separate systems. A separate fan system
shall be used for each bank of elevators.
707.14.2.3.4 Fan capacity.
The supply fan shall either be adjustable with a capacity
of at least 1,000 cfm (.4719 m3/s) per door,
or that specified by a registered design professional
to meet the requirements of a designed pressurization
system.
707.14.2.4 Standby power. The pressurization system
shall be provided with standby power from the same source
as other required emergency systems for the building.
707.14.2.5 Activation of pressurization system. The
elevator pressurization system shall be activated upon activation
of the building fire alarm system or upon activation of
the elevator lobby smoke detectors.