Page 93 - 2018_IMC

DUCT SYSTEMS

[F] 606.4 Controls operation. Upon activation, the smoke shall be installed in accordance with the requirements of this
detectors shall shut down all operational capabilities of the air section, and the manufacturer’s instructions and listing.
distribution system in accordance with the listing and label- [BF] 607.2.1 Smoke control system. Where the installa-
ing of appliances used in the system. Air distribution systems tion of a fire damper will interfere with the operation of a
that are part of a smoke control system shall switch to the required smoke control system in accordance with Section
smoke control mode upon activation of a detector. 909 of the International Building Code, approved alterna-
[F] 606.4.1 Supervision. The duct smoke detectors shall tive protection shall be used. Where mechanical systems
be connected to a fire alarm system where a fire alarm sys- including ducts and dampers used for normal building
tem is required by Section 907.2 of the International Fire ventilation serve as part of the smoke control system, the
Code. The actuation of a duct smoke detector shall acti- expected performance of these systems in smoke control
vate a visible and audible supervisory signal at a con- mode shall be addressed in the rational analysis required
stantly attended location. In facilities that are required to by Section 909.4 of the International Building Code.
be monitored by a supervising station, duct smoke detec- 607.2.2 Hazardous exhaust ducts. Fire dampers for haz-
tors shall report only as a supervisory signal, not as a fire ardous exhaust duct systems shall comply with Section
alarm. 510.
Exceptions: [BF] 607.3 Damper testing, ratings and actuation. Damper
1. The supervisory signal at a constantly attended testing, ratings and actuation shall be in accordance with Sec-
location is not required where the duct smoke tions 607.3.1 through 607.3.3.5.
detector activates the building’s alarm-indicating [BF] 607.3.1 Damper testing. Dampers shall be listed
appliances. and labeled in accordance with the standards in this sec-
2. In occupancies not required to be equipped with a tion. Fire dampers shall comply with the requirements of
fire alarm system, actuation of a smoke detector UL 555. Only fire dampers labeled for use in dynamic sys-
shall activate a visible and audible signal in an tems shall be installed in heating, ventilating and air-con-
approved location. Duct smoke detector trouble ditioning systems designed to operate with fans on during
conditions shall activate a visible or audible sig- a fire. Smoke dampers shall comply with the requirements
nal in an approved location and shall be identi- of UL 555S. Combination fire/smoke dampers shall com-
fied as air duct detector trouble. ply with the requirements of both UL 555 and UL 555S.
Ceiling radiation dampers shall comply with the require-
ments of UL 555C or shall be tested as part of a fire-resis-
SECTION 607 tance-rated floor/ceiling or roof/ceiling assembly in
DUCT AND TRANSFER OPENINGS accordance with ASTM E119 or UL 263. Only ceiling
[BF] 607.1 General. The provisions of this section shall gov- radiation dampers labeled for use in dynamic systems shall
ern the protection of duct penetrations and air transfer open- be installed in heating, ventilation and air-conditioning
ings in assemblies required to be protected. systems designed to operate with fans on during a fire.
Corridor dampers shall comply with requirements of both
[BF] 607.1.1 Ducts between shafts. Ducts transitioning
horizontally between shafts shall not require a shaft enclo- UL 555 and UL 555S. Corridor dampers shall demonstrate
sure provided that the duct penetration into each associ- acceptable closure performance when subjected to 150
ated shaft is protected with dampers complying with this feet per minute (0.76 mps) velocity across the face of the
section. damper using the UL 555 fire exposure test.
[BF] 607.1.2 Ducts that penetrate fire-resistance-rated [BF] 607.3.2 Damper rating. Damper ratings shall be in
assemblies without dampers. Ducts that penetrate fire- accordance with Sections 607.3.2.1 through 607.3.2.4.
resistance-rated walls and are not required by this section [BF] 607.3.2.1 Fire damper ratings. Fire dampers
to have fire dampers shall comply with the requirements of shall have the minimum rating specified in Table
Sections 714.3 through 714.4.3 of the International Build- 607.3.2.1.
ing Code. Ducts that penetrate horizontal assemblies not [BF] TABLE 607.3.2.1
required to be contained within a shaft and not required by FIRE DAMPER RATING
this section to have fire dampers shall comply with the MINIMUM
requirements of Section 714.5 of the International Build- DAMPER
TYPE OF PENETRATION RATING (hour)
ing Code. Less than 3-hour fire-resistance-rated assemblies 1 /
1
[BF] 607.1.2.1 Ducts that penetrate nonfire-resis- 2
tance-rated assemblies. The space around a duct pene- 3-hour or greater fire-resistance-rated assemblies 3
trating a nonfire-resistance-rated floor assembly shall [BF] 607.3.2.2 Smoke damper ratings. Smoke
comply with Section 717.6.3 of the International Build- damper leakage ratings shall be Class I or II. Elevated
ing Code.
temperature ratings shall be not less than 250°F
[BF] 607.2 Installation. Fire dampers, smoke dampers, com- (121°C).
bination fire/smoke dampers and ceiling radiation dampers [BF] 607.3.2.3 Combination fire/smoke damper rat-
located within air distribution and smoke control systems
ings. Combination fire/smoke dampers shall have the

76 2018 INTERNATIONAL MECHANICAL CODE 
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