Page 81 - 2018_IMC

EXHAUST SYSTEMS

Section 909 of the International Building Code shall undergo 2. Interior exit stairways and ramps and exit passageways:
special inspections and tests sufficient to verify the proper A/A = 0.00035
w
commissioning of the smoke control design in its final 3. Enclosed exit access stairways and ramps and all other
installed condition. The design submission accompanying the shafts: A/A = 0.00150
construction documents shall clearly detail procedures and w
F
methods to be used and the items subject to such inspections 4. Floors and roofs: A/A = 0.00050
and tests. Such commissioning shall be in accordance with where:
generally accepted engineering practice and, where possible, A = Total leakage area, square feet (m ).
2
based on published standards for the particular testing A = Unit floor or roof area of barrier, square feet (m ).
2
involved. The special inspections and tests required by this F 2
w
section shall be conducted under the same terms as found in A = Unit wall area of barrier, square feet (m ).
Section 1704 of the International Building Code. The leakage area ratios shown do not include openings
[F] 513.4 Analysis. A rational analysis supporting the types created by gaps around doors and operable windows. The
of smoke control systems to be employed, their methods of total leakage area of the smoke barrier shall be determined in
operation, the systems supporting them and the methods of accordance with Section 513.5.1 and tested in accordance
construction to be utilized shall accompany the submitted with Section 513.5.2.
construction documents and shall include, but not be limited [F] 513.5.1 Total leakage area. Total leakage area of the
to, the items indicated in Sections 513.4.1 through 513.4.7. barrier is the product of the smoke barrier gross area times
the allowable leakage area ratio, plus the area of other
[F] 513.4.1 Stack effect. The system shall be designed
such that the maximum probable normal or reverse stack openings such as gaps around doors and operable win-
effects will not adversely interfere with the system’s capa- dows.
bilities. In determining the maximum probable stack [F] 513.5.2 Testing of leakage area. Compliance with the
effects, altitude, elevation, weather history and interior maximum total leakage area shall be determined by
temperatures shall be used. achieving the minimum air pressure difference across the
barrier with the system in the smoke control mode for
[F] 513.4.2 Temperature effect of fire. Buoyancy and
expansion caused by the design fire in accordance with mechanical smoke control systems utilizing the pressur-
Section 513.9 shall be analyzed. The system shall be ization method. Compliance with the maximum total leak-
designed such that these effects do not adversely interfere age area of passive smoke control systems shall be verified
with its capabilities. through methods such as door fan testing or other meth-
ods, as approved by the fire code official.
[F] 513.4.3 Wind effect. The design shall consider the
adverse effects of wind. Such consideration shall be con- [F] 513.5.3 Opening protection. Openings in smoke bar-
sistent with the wind-loading provisions of the Interna- riers shall be protected by automatic-closing devices actu-
tional Building Code. ated by the required controls for the mechanical smoke
control system. Door openings shall be protected by door
[F] 513.4.4 HVAC systems. The design shall consider the assemblies complying with the requirements of the Inter-
effects of the heating, ventilating and air-conditioning national Building Code for doors in smoke barriers.
(HVAC) systems on both smoke and fire transport. The
analysis shall include all permutations of systems’ status. Exceptions:
The design shall consider the effects of fire on the HVAC 1. Passive smoke control systems with automatic-
systems. closing devices actuated by spot-type smoke
detectors listed for releasing service installed in
[F] 513.4.5 Climate. The design shall consider the effects
of low temperatures on systems, property and occupants. accordance with the International Building Code.
Air inlets and exhausts shall be located so as to prevent 2. Fixed openings between smoke zones that are
snow or ice blockage. protected utilizing the airflow method.
[F] 513.4.6 Duration of operation. All portions of active 3. In Group I-1, Condition 2, Group I-2 and ambula-
or engineered smoke control systems shall be capable of tory care facilities, where a pair of opposite-
continued operation after detection of the fire event for a swinging doors are installed across a corridor in
period of not less than either 20 minutes or 1.5 times the accordance with Section 513.5.3.1, the doors
calculated egress time, whichever is greater. shall not be required to be protected in accor-
dance with Section 716 of the International
513.4.7 Smoke control system interaction. The design
shall consider the interaction effects of the operation of Building Code. The doors shall be close-fitting
multiple smoke control systems for all design scenarios. within operational tolerances and shall not have a
3
center mullion or undercuts in excess of / inch
4
[F] 513.5 Smoke barrier construction. Smoke barriers (19.1 mm), louvers or grilles. The doors shall
required for passive smoke control and a smoke control sys- have head and jamb stops and astragals or rabbets
tem using the pressurization method shall comply with Sec- at meeting edges and, where permitted by the
tion 709 of the International Building Code. The maximum door manufacturer’s listing, positive-latching
allowable leakage area shall be the aggregate area calculated devices are not required.
using the following leakage area ratios:
4. In Group I-2 and ambulatory care facilities,
1. Walls: A/A = 0.00100
w where such doors are special-purpose horizontal

64 2018 INTERNATIONAL MECHANICAL CODE 
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