SECTION 15910

DUCTWORK ACCESSORIES

PART 1 GENERAL

WORK INCLUDED

Volume control dampers.

Fire dampers.

Combination fire and smoke dampers.

Backdraft dampers.

Air turning devices.

Flexible duct connections.

Duct access doors.

Duct test holes.

RELATED WORK

Section 15242 - Vibration Isolation.

Section 15890 - Ductwork.

Section [____] - Air Terminal Units: Medium and high pressure damper assemblies.

REFERENCES

NFPA 90A - Installation of Air Conditioning and Ventilating Systems.

SMACNA - Low Pressure Duct Construction Standards.

UL 33 - Heat Responsive LInks for Fire-Protection Service.

UL 555 - Fire Dampers and Ceiling Dampers.

SUBMITTALS

Submit [shop drawings and] [product data] under provisions of Section [01300.] [01340.]

Provide shop drawings for shop fabricated assemblies indicated, including [volume control dampers] [duct access doors] [duct test holes]. [Provide product data for hardware used.]

Submit manufacturer's installation instructions under provisions of Section [01300] [01340], for [fire dampers] [and] [combination fire and smoke dampers.]

PART 2 PRODUCTS

VOLUME CONTROL DAMPERS.

Fabricate in accordance with SMACNA Low Pressure Duct Construction Standards, and as indicated.

Fabricate splitter dampers of material same gage as duct to 24 inches (600 mm) size in either direction, and two gages heavier for sizes over 24 inches (600 mm).

Fabricate splitter dampers of [single] [double] thickness sheet metal to streamline shape. Secure blade with continuous hinge or rod. Operate with minimum 1/4 inch (6 mm) diameter rod in self aligning, universal joint action flanged bushing with set screw.

Fabricate single blade dampers for duct sizes to [9-1/2 x 30 inch (240 x 760 mm).] [12 x 48 inch (300 x 1220 mm).]

Fabricate multi-blade damper of opposed blade pattern with maximum blade sizes 12 x 72 inch (300 x 1825 mm). Assemble center and edge crimped blades in prime coated or galvanized channel frame with suitable hardware.

Except in round ductwork [12] [____] inches ([300] [____] mm) and smaller, provide end bearings. On multiple blade dampers, provide oil-impregnated nylon or sintered bronze bearings.

Provide locking, indicating quadrant regulators on single and multi-blade dampers. [Where rod lengths exceed 30 inches (750 mm) provide regulator at both ends.]

On insulated ducts mount quadrant regulators on stand-off mounting brackets, bases, or adapters.

ACCEPTABLE MANUFACTURERS - [FIRE DAMPERS] [AND] [COMBINATION FIRE AND SMOKE DAMPERS]

[_________________________________.]

[_________________________________.]

[_________________________________.]

Substitutions: Under provisions of Section [01600.] [01630.]

FIRE DAMPERS

Fabricate in accordance with NFPA 90A and UL 555, and as indicated.

Fabricate ceiling firestop flaps of galvanized steel, 22 gage (0.76 mm) frame and 16 gage (1.5 mm) flap, two layers 0.125 inch (3.2 mm) ceramic fiber on top side [, and one layer on bottom side for round flaps], with locking clip.

Fabricate ceiling dampers of galvanized steel, 22 gage (0.76 mm) frame, stainless steel closure spring, and light weight, heat retardant non-asbestos fabric blanket closure.

Fabricate curtain type dampers of galvanized steel with interlocking blades. Provide stainless steel closure springs and latches for horizontal installations. Configure with blades out of air stream except for low pressure ducts up to 12 inches (300 mm) in height.

Fabricate multiple blade fire dampers with 16 gage (1.5 mm) galvanized steel frame and blades, oil-impregnated bronze or stainless steel sleeve bearings and plated steel axles, 1/8 x 1/2 inch (3.2 x 12.7 mm) plated steel concealed linkage, stainless steel closure spring, blade stops, and lock.

Fusible links, UL 33, shall separate at [160] [212] [____] degrees F ([71] [100] [____] degrees C). Provide adjustable link straps for combination fire/balancing dampers.

COMBINATION FIRE AND SMOKE DAMPERS

Fabricate in accordance with NFPA 90A and UL 555, and as indicated.

Provide factory sleeve for each damper. Install damper operator on exterior of sleeve and link to damper operating shaft.

Fabricate with multiple blades with 16 gage (1.5 mm) galvanized steel frame and blades, oil-impregnated bronze or stainless steel sleeve bearings and plated steel axles, stainless steel jamb seals, 1/8 x 1/2 inch (3.2 x 12.7 mm) plated steel concealed linkage, stainless steel closure spring, blade stops, and lock, and 1/2 inch (12.7 mm) actuator shaft.

Operators shall be spring return [pneumatic type suitable for operation on 0-20 psig (0-140kPa) instrument air.] [electric type suitable to operate on 120 V AC, 60 cycle.] Operators shall be UL listed and labelled. [Provide end switches to indicate damper position.]

SMOKE DAMPERS

Fabricate in accordance with NFPA 90A and UL 555, and as indicated.

Normally Closed Smoke Vent Dampers: Curtain type, opening by gravity upon actuation of electro thermal link, flexible stainless steel blade edge seals to provide constant sealing pressure.

Normally Open Smoke Damper: Curtain type, closing upon actuation of electro thermal link, flexible stainless steel blade edge seals to provide constant sealing pressure, stainless steel springs with locking devices ensure positive closure for units mounted horizontally.

Motorized Smoke Dampers: Curtain type, normally open with power on, close automatically when power is interrupted, UL-listed and labelled damper and damper operator.

Electro thermal Link: Fusible link which melts when subject to local heat of [165] [____] degrees F ([74] [____] degrees C.) and from external electrical impulse; UL listed and labelled.

ACCEPTABLE MANUFACTURERS - BACKDRAFT DAMPERS

[_________________________________.]

[_________________________________.]

[_________________________________.]

Substitutions: Under provisions of Section [01600.] [01630.]

BACKDRAFT DAMPERS.

Gravity backdraft dampers, size [18 x 18 inches (457 x 457mm)] [________] or smaller, furnished with air moving equipment, may be air moving equipment manufacturers standard construction.

Fabricate multi-blade, parallel action gravity balanced backdraft dampers of [16 gage (1.5 mm) galvanized steel], [or] [extruded aluminum], with [center pivoted] blades of maximum 6 inch (150 mm) width, with felt or flexible vinyl sealed edges, linked together in rattle-free manner with 90 degree stop, steel ball bearings, and plated steel pivot pin; adjustment device to permit setting for varying differential static pressure; Model [________________] manufactured by [________________.]

ACCEPTABLE MANUFACTURERS - AIR TURNING DEVICES

[_________________________________.]

[_________________________________.]

[_________________________________.]

Substitutions: Under provisions of Section [01600.] [01630.]

AIR TUNING DEVICES

Multi-blade device with blades aligned in short dimension; steel or aluminum construction; with individually adjustable blades, mounting straps; Model [________] manufactured by [________________.]

****** [OR] ******

Multi-blade device with radius blades attached to pivoting frame and bracket, steel or aluminum construction, with [push-pull operator strap] [ceiling mounted rotary operator knob] [worm drive mechanism with 18 inch (450 mm) long removable key operator]; Model [________] manufactured by [________.]

ACCEPTABLE MANUFACTURERS - FLExIBLE DUCT CONNECTIONS

[_________________________________.]

[_________________________________.]

[_________________________________.]

Substitutions: Under provisions of Section [01600.] [01630.]

FLEXIBLE DUCT CONNECTIONS

Fabricate in accordance with SMACNA Low Pressure Duct Construction Standards, and as indicated.

UL listed fire-retardant neoprene coated woven glass fiber fabric to NFPA 90A, minimum density [20] [36] oz per sq yd ([0.68] [1.22] kg/sq m), approximately [2] [3] [6] inches ([50] [75] [150] mm) wide, crimped into metal edging strip.

Leaded vinyl sheet, minimum 0.55 inch (14 mm) thick, 0.87 lbs per sq ft (4.2 kg/sq m), 10 dB attenuation in 10 to 10,000 Hz range.

ACCEPTABLE MANUFACTURERS - DUCT ACCESS DOORS

[_________________________________.]

[_________________________________.]

[_________________________________.]

Substitutions: Under provisions of Section [01600.] [01630.]

DUCT ACCESS DOORS

Fabricate in accordance with SMACNA Low Pressure Duct Construction Standards and as indicated.

Review locations prior to fabrication.

Fabricate rigid and close-fitting doors of galvanized steel with sealing gaskets and quick fastening locking devices. For insulated ductwork, install minimum one inch (25 mm) thick insulation with sheet metal cover.

Access doors smaller than 12 inches (300 mm) square may be secured with sash locks.

Provide two hinges and two sash locks for sizes up to 18 inches (450 mm) square, three hinges and two compression latches with outside and inside handles for sizes up to 24 x 48 inches (600 x 1200 mm). Provide an additional hinge for larger sizes.

Access doors with sheet metal screw fasteners are not acceptable.

DUCT TEST HOLES

Cut or drill temporary test holes in ducts as required. Cap with neat patches, neoprene plugs, threaded plugs, or threaded or twist-on metal caps.

Permanent test holes shall be factory fabricated, air tight flanged fittings with screw cap. Provide extended neck fittings to clear insulation.

PART 3 EXECUTION

INSTALLATION

Install accessories in accordance with manufacturer's instructions.

Provide balancing dampers at points on low pressure supply, return, and exhaust systems where branches are

taken from larger ducts as required for air balancing.

Use splitter dampers only where indicated.

Provide balancing dampers on medium and high pressure systems where indicated. Refer to Section [____] - Air Terminal Units.

Provide fire dampers [, combination fire and smoke dampers] [and smoke dampers] at locations indicated, where ducts and outlets pass through fire rated components [, and where required by authorities having jurisdiction]. Install with required perimeter mounting angles, sleeves, breakaway duct connections, corrosion resistant springs, bearings, bushings and hinges.

Demonstrate re-setting of fire dampers to authorities having jurisdiction and Owner's representative.

Provide backdraft dampers on exhaust fans or exhaust ducts nearest to outside and where indicated.

Provide flexible connections immediately adjacent to equipment in ducts associated with fans and motorized equipment. [Cover connections to medium and high pressure fans with leaded vinyl sheet, held in place with metal straps.]

Provide duct access doors for inspection and cleaning before and after filters, coils, fans, automatic dampers, at fire dampers, and elsewhere as indicated. Provide minimum 8 x 8 inch (200 x 200 mm) size for hand access, 18 x 18 inch (450 x 450 mm) size for shoulder access, and as indicated.

Provide duct test holes where indicated and required for testing and balancing purposes.

END OF SECTION