WAC 51-50-0707   Section 707 -- Shaft enclosures.  


707.14.2 Enclosed elevator lobby pressurization alternative. Where elevator hoistway pressurization is provided in lieu of required enclosed elevator lobbies, the pressurization system shall comply with this section.


707.14.2.1 Pressurization requirements. Elevator hoistways shall be pressurized to maintain a minimum positive pressure of 0.10 inches of water column with respect to adjacent occupied space on all floors and a maximum pressure so as to not prevent the automatic operation of the elevator doors, as well as accounting for the stack and wind effect expected on the mean low temperature January day. This pressure shall be measured at the midpoint of each hoistway door, with all hoistway doors open at the designated primary recall level and all other hoistway doors closed. The supply air intake shall be from an outside, uncontaminated source located a minimum distance of 20 feet 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 1000-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.


707.14.2.6 Elevator doors. Each elevator door shall operate properly when hoistway pressurization is in effect.


707.14.2.7 Hoistway venting. Hoistway venting required by Section 3004 need not be provided for pressurized elevator shafts.


707.14.2.8 Machine rooms. Elevator machine rooms shall be pressurized in accordance with this section unless separated from the hoistway shaft by construction in accordance with Section 707.


707.14.2.9 Special inspection. Special inspection for performance shall be required in accordance with Section909.18.8 . System acceptance shall be in accordance with Section 909.19.



[Statutory Authority: RCW 19.27.074, 19.27.020, and chapters 70.92, 19.27, and 34.05 RCW. 07-01-091, § 51-50-0707, filed 12/19/06, effective 7/1/07. Statutory Authority: RCW 19.27.031 and 19.27.074. 04-01-108, § 51-50-0707, filed 12/17/03, effective 7/1/04.]