7. Enclosed elevator
lobbies are not required where the elevator serves only
in accordance with Section 406.3.
708.14.2
Enclosed elevator
lobby. Where elevator hoist- way pressurization is provided in lieu of
required enclosed elevator lobbies, the pressurization system shall comply with
this section.
708.14.2.1
Pressurization
requirements. Elevator hoistways shall be pressurized to maintain a
minimum positive pressure of 0.10 inch of water (25 Pa) and a maximum positive
pressure of 0.25 inch of water (67 Pa) with respect to adjacent occupied space
on all floors. This pressure shall be measured at the midpoint of each hoistway
door, with all elevator cars at the floor of recall and all hoistway doors on
the floor of recall open and all other hoistway doors closed. The opening and
closing of hoistway doors at each level must be demonstrated during this test.
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.
708.14.2.2
Rational
analysis. A rational analysis complying with Section 909.4 shall be
submitted with the construction documents.
708.14.2.3
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.
708.14.2.4
Fan system. The fan system provided for the pressurization system
shall be as required by this section.
708.14.2.4.1
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.
708.14.2.4.2
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.
708.14.2.4.3
Separate systems.
A separate fan system shall be used for each elevator hoistway.
708.14.2.4.4
Fan capacity. The
supply fan shall either be adjustable with a capacity of at least 1,000 cfm
(0.4719 m3/s) per door, or that specified by a
registered design professional to meet the requirements of a
designed pressurization system.
708.14.2.5
Standby power. The
pressurization system shall be provided with standby power from the same source
as other required emergency systems for the building.
708.14.2.6
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. Where both a building fire alarm system and elevator
lobby smoke detectors are present, each shall be independently capable of
activating the pressurization system.
708.14.2.7
Special inspection.
Special inspection for performance shall be required in
accordance with Section 909.18.8. System acceptance shall be in accordance with
Section 909.19.
708.14.2.8
Marking and identification. Detection and control systems shall be
marked in accordance with Section 909.14.
708.14.2.9
Control diagrams.
Control diagrams shall be provided in accordance with Section 909.15.
708.14.2.10
Control panel. A
control panel complying with Section 909.16 shall be provided.
708.14.2.11
System response
time. Hoistway pressurization systems shall comply with the requirements
for smoke control system response time in Section 909.17.