Washington Administrative Code › Title 51 - Enterprise Services, Department of (Building Code Council) › Chapter 51-52 - State Building Code adoption and amendment of the 2021 edition of the International Mechanical Code › Section 51-52-0607 - Section 607-Ducts and transfer openings

Current through Register Vol. 24-14, July 15, 2024
607.5.2 Fire barriers.
Ducts and air transfer
				openings that penetrate fire barriers shall be protected with
listed
fire dampers installed in accordance with their
				listing. Ducts and air transfer openings shall not penetrate enclosures for
				interior exit stairways and ramps and exit passageways except as permitted by
				Sections 1023.5 and 1024.6, respectively, of the
International Building
				Code
.
EXCEPTION:
Fire dampers are not required at penetrations of fire
							 barriers where any of the following apply:
1. Penetrations are tested in accordance with ASTM
							 E119 or UL 263 as part of the fire-resistance-rated assembly.
2. Ducts are used as part of an
approved
smoke control system in accordance with Section 513
							 and where the fire damper would interfere with the operation of the smoke
							 control system.
3. Such walls are penetrated by fully ducted HVAC
							 systems, have a required fire-resistance rating of 1 hour or less, are in areas
							 of other than Group H and are in buildings equipped throughout with an
							 automatic sprinkler system in accordance with Section 903.3.1.1 or 903.3.1.2 of
							 the
International Building Code
. For the purposes of this
							 exception, a fully ducted HVAC system shall be a duct system for the
							 structure's HVAC system. Such a duct system shall be constructed of sheet steel
							 not less than 26 gage (0.0217 inch (0.55 mm)) thickness and shall be continuous
							 from the air-handling
appliance
or
equipment
to the air outlet and inlet terminals. Flexible air connectors shall be
							 permitted in a fully ducted system, limited to the following
							 installations:
3.1. Nonmetallic flexible connections that connect a
							 duct to an air handling unit or
equipment
located within a
							 mechanical room or located outdoors in accordance with Section 603.9.
3.2. Nonmetallic flexible air connectors in
							 accordance with Section 603.6.2 that connect an overhead metal duct to a
							 diffuser, grille, or register where the metal duct and diffuser, grille, or
							 register are located within the same room.
607.5.3 Fire partitions.
Ducts and air transfer
				openings that penetrate fire partitions shall be protected with listed fire
				dampers installed in accordance with their listing.
EXCEPTION:
In
occupancies
other than Group H,
							 fire dampers are not required where any of the following apply:
1. Corridor walls in buildings equipped throughout
							 with an automatic sprinkler system in accordance with Section 903.3.1.1 or
							 903.3.1.2 of the
International Building Code
and the duct is
							 protected as a through penetration in accordance with Section 714 of the
International Building Code
.
2. The partitions are tenant partitions in covered
							 and open mall buildings where the walls are not required by provisions
							 elsewhere in the
International Building Code
to extend to the
							 underside of the floor or roof sheathing, slab, or deck above.
3. The duct system is constructed of
approved
materials in accordance with Section 603 and the duct
							 penetrating the wall complies with all of the following requirements:
3.1. The duct shall not exceed 100 square inches
							 (0.06 m2).
3.2. The duct shall be constructed of steel not less
							 than 0.0217 inch (0.55 mm) in thickness.
3.3. The duct shall not have openings that
							 communicate the corridor with adjacent spaces or rooms.
3.4. The duct shall be installed above a
							 ceiling.
3.5. The duct shall not terminate at a wall register
							 in the fire-resistance-rated wall.
3.6. A minimum 12-inch-long (305 mm) by
							 0.060-inch-thick (1.52 mm) steel sleeve shall be centered in each duct opening.
							 The sleeve shall be secured to both sides of the wall and all four sides of the
							 sleeve with minimum 1.5-inch by 1.5-inch by 0.060-inch (38 mm by 38 mm by 1.52
							 mm) steel retaining angles. The retaining angles shall be secured to the sleeve
							 and the wall with No. 10 (M5) screws. The annular space between the steel
							 sleeve and the wall opening shall be filled with rock (mineral) wool batting on
							 all sides.
4. Such walls are penetrated by fully ducted HVAC
							 systems, have a required fire-resistance rating of 1 hour or less, and are in
							 areas of other than Group H and are in buildings equipped throughout with an
							 automatic sprinkler system in accordance with Section 903.3.1.1 or 903.3.1.2 of
							 the
International Building Code
. For the purposes of this
							 exception, a fully ducted HVAC system shall be a duct system for conveying
							 supply, return or
exhaust air
as part of the structure's HVAC
							 system. Such a duct system shall be constructed of sheet steel not less than 26
							 gage (0.0217 inch (0.55 mm)) in thickness and shall be continuous from the
							 air-handling
appliance
or
equipment
to the
							 air outlet and inlet terminals. Flexible air connections shall be permitted in
							 a fully ducted system, limited to the following installations:
4.1. Nonmetallic flexible connections that connect a
							 duct to an air-handling unit or equipment located within a mechanical room or
							 located outdoors in accordance with Section 603.9.
4.2. Nonmetallic flexible air connectors in
							 accordance with Section 603.2.6 that connect an overhead metal duct to a
							 diffuser, grille, or register where the metal duct and diffuser, grille, or
							 register are located in the same room. Where the fully ducted HVAC system metal
							 ductwork penetrates a corridor fire partition, the ductwork shall be continuous
							 without openings to the corridor, to a mechanical room, or to a shaft
							 enclosure.