SECTION 15910 DUCT ACCESSORIES PART 1 - GENERAL 1.01 RELATED DOCUMENTS A. Drawings and general provisions of Contract including General and Supplementary Conditions, Division-1 Specification Sections, and the Mechanical General Requirements Section 15050 apply to work of this Section, as if repeated herein. 1.02 QUALITY ASSURANCE A. Construct and test fire dampers in accordance with UL Standard 555. Each fire damper shall have a 1-1/2 or 3 hour UL fire protection rating, as required, and shall include a UL label in accordance with established UL labeling procedures. In addition, dampers shall be State Fire Marshal listed. B. Construct fire damper fusible links to UL Standard 33, Fusible links for Fire Protection Service, for service intended. C. Demonstrate resetting of fire dampers to authorities having jurisdiction and Owner's representative. D. Smoke dampers shall be classified by UL as a leakage rated damper for use in smoke control systems, under UL 555 S, and shall bear a UL label attesting to same. 1.03 REFERENCES A. Accessories shall meet the requirements of NFPA 90 A and NFPA 101, as applicable. B. Fabricate in accordance with ASHRAE handbooks and SMACNA duct manuals. 1.04 SUBMITTALS A. Submit in accordance with Division-1 and Section 15050. B. Submit shop drawings of factory fabricated assemblies.
C. Submit manufacturer's printed installation instructions. D. Provide a field mock-up fire damper installation assembly complete with wall framing, wall board, wall opening filler pieces, perimeter mounting angles, sleeve, breakaway duct connections, and access door. Obtain Architect's approval of mock up prior to starting damper installation. PART 2 - PRODUCTS 2.01 ACCEPTABLE MANUFACTURERS A. Fire Dampers: 2. Phillips 3. Prefco 4. Ruskin B. Smoke Dampers 2. Johnson Controls 3. Phillips 4. Prefco 5. Ruskin C. Combination Fire/Smoke Dampers: 2. Phillips 3. Prefco 4. Ruskin D. Control Dampers: 2. Ruskin 3. Or equal.
E. Balancing Dampers: 2. Phillips 3. Ruskin 4. Contractor fabricated F. Access Doors - Ductwork: 1. Ductmate 2. Milcor 3. Ruskin 4. Contractor fabricated 2.02 ACCESS DOORS - DUCTWORK A. Construction: Close fitting rigid galvanized steel assemblies with sealing gaskets and quick fastening locking devices. For insulated ductwork, install minimum 1" thick insulation with sheet metal cover. B. Locking Devices: Provide 2 hinges and 2 sash locks or 2 spring loaded threaded knobs and bolts for sizes up to 18" square; 2 hinges and 2 compression latches with outside and inside handles for sizes up to 24" by 48". Provide an additional hinge for larger sizes. C. Option: Doors may be vendor purchased or Contractor fabricated. 2.03 COMBINATION FIRE/SMOKE DAMPERS A. General: 1. Provide combination fire/smoke dampers at fire rated/smoke partitions and walls in accordance with NFPA 90 A, NFPA 101, and UBC Standard Nos. 43-7 and 43-12. Refer to Drawings.
2. Each combination fire/smoke damper shall be 1-1. 2-hour fire rated under UL 555 S, and further classified by Underwriter's Laboratories as a leakage rated damper for use in smoke control systems under the latest version of UL 555 S and bear a UL label attesting to same. Damper manufacturer shall have tested, and qualified with UL, a complete range of damper sizes. Having a single damper size tested and UL Qualified is not acceptable. The leakage rating under UL 555 S shall be no higher than Leakage Class II (10 CFM/sq ft 2 at 1" wg). 3. As part of the UL qualification, dampers shall have demonstrated a capacity to operate (open and close) under HVAC system operating conditions with pressures of at least 4" wg in the closed position, and 3500 fpm air velocity in the open position. 4. Dampers and their operator shall be qualified under UL 555 S to an elevated temperature of 350 o F with electric operators for engineered smoke systems. Operators shall be installed by the damper manufacture at time of fabrication. The assembly shall meet UL 555 S qualifications for dampers and operators. 5. Operators shall be electric type operating on 120 VAC, 60 H z. Provide spring-return, fail closed type operators that close damper upon power interruption. Damper operators shall be UL listed as fire damper operators and shall bear the appropriate UL operator label. 6. Provide damper limit switches for interlocking purposes to activate when the dampers is in the 100% open position. 7. Provide each combination fire/smoke damper with a factory sleeve of length and gauge required for satisfactory installation with damper operator and limit switch factory installed on exterior sleeve and properly linked to damper operating shaft. Mount operator and switch outside of the fire wall to prevent interference with rated installation retaining angles. 8. Equip each combination fire/smoke damper with a fusible link which melts at 165 o F causing damper to close and lock in a closed position.
B. Rectangular Dampers: 1. Provide airfoil-shaped, double skin blades, with 14-gauge equivalent thickness, maximum 6" wide, having shafts/bearings designed to meet temperature requirements. Provide 5" by 16- gauge galvanized channel frame. Seal blade edges with silicone rubber and jamb with flexible metal compression. 2. The pressure drop for a 24" by 24" damper handling 8500 CFM shall be 0.08" wg or less, under standard air conditions. 3. Dampers shall be Ruskin FSD60 with fusible link. C. Round Dampers: 1. Construct dampers similar to rectangular dampers, except with sleeve and connection for round ducts. 2. Dampers shall be Ruskin FSD60 with round connection style CR and with fusible link. D. Ceiling Mounted Damper 1. Dampers shall be Ruskin FSD36C. 2.04 CONTROL DAMPERS A. General: 1. Provide control dampers with parallel or opposed blades to suit application. 2. Coordinate with control subcontractor for operators, control accessories, and sequence of operation. B. Rectangular Dampers: 1. Provide airfoil-shaped, double skin blades, with 14-gauge equivalent thickness, maximum 6" wide, having shafts/bearings designed to meet temperature requirements and maximum velocity (3500 fpm) requirements. Provide minimum 3-1/2" by 16-gauge galvanized channel frame. Seal blade edges with extruded vinyl and jamb with flexible metal compression. 2. The pressure drop for a 24" by 24" damper handling 8500 CFM shall be 0.08" wg or less, under standard air conditions.
3. Dampers shall be Ruskin CD60 or Johnson Controls D-1300. C. Round Dampers: 1. Construct blades with 2 layers galvanized steel 14-gauge equivalent thickness, neoprene seals sandwiched between blade sheets, and shafts/bearings designed to meet dynamic and temperature requirements. Provide 12-gauge reinforced galvanized steel frame, neoprene sandwiched between blade sheets. 2. Pressure drop for a 12" diameter damper handling 2500 CFM shall be 0.10" wg or less, under standard air conditions. 3. Dampers shall be Ruskin CDRS-25. 2.05 BALANCING DAMPERS A. General: 1. Provide dampers throughout the duct systems to facilitate complete balancing. 2. Dampers may be vendor purchased or contractor fabricated. B. Rectangular Dampers with Either Width or Height Dimension less Than 24": 1. Butterfly type dampers with 22-gauge galvanized steel or duct casing angle reinforced as required. 2. Provide single thickness 16-gauge minimum, galvanized steel blades, welded or bolted to 1/2" minimum diameter through shaft. Permanently mark end of shaft to indicate blade position and fit with a locking quadrant mounted on outside of frame. Bearings shall be pressed into frame and designed for dynamic requirements.
Than C. Rectangular Dampers With Both Width and Height Dimensions Greater 24": 1. Frame, 5" by 1", 16-gauge galvanized steel channel. Blades, 8" maximum width, 16-gauge galvanized steel, opposed blade, having shafts/bearings designed to meet dynamic requirements, positively locked to shafts. 2. Control shaft shall be 3/8" square, plated steel, permanently marked to indicate blade position, and fitted with locking quadrant mounted on outside of frame. 3. Pressure drop for a 28" by 28" damper handling 7600 CFM shall be 0.05" wg or less, under standard air conditions. 4. Dampers shall be Ruskin MD-35. D. Round Dampers Up to 24" Diameter: reinforced. 1. Frame shall be 18-gauge galvanized steel, or duct casing 2. Provide single thickness 16-gauge galvanized steel blades, welded or permanently bolted to 1/2" minimum diameter through shaft. Permanently mark end of shaft to indicate blade position and fit with a locking quadrant mounted on outside of frame. Bearings shall be pressed into frame and designed for dynamic requirements. E. Identification: Provide 1" wide nylon ribbon for each damper, color as follows: supply air, red return air, blue exhaust air, yellow. Tie through hole at end of damper quadrant, leaving at least 12" of ribbon hanging free. Attach ribbons at the time each damper is installed. 2.06 FLEXIBLE CONNECTIONS A. Fabricate of neoprene coated flameproof fabric tightly crimped into metal edging strip and attach to ducting and equipment by screws or bolts at 6" intervals. Flexible duct connections shall be provided with a sufficient material width to prevent interference with free operation of fan vibration isolation systems.
2.07 APPLICATION A. Access Doors: Provide for inspection and cleaning before and after filters, coils, fans, automatic dampers, at fire dampers, smoke dampers, and combination fire/smoke dampers. Review locations prior to fabrication. Doors shall be square, sized to three quarters of the larger of the duct width or height, but no smaller than 8" x 8" nor no larger than 24" x 24". Provide 4" by 4" quick-opening duct access doors for inspection at balancing dampers. B. Fire Dampers: Provide at locations, where ducts and outlets pass through fire rated components, and where required by authorities having jurisdiction. Provide fire dampers complete with required perimeter mounting angles, sleeves, breakaway duct connections, corrosion resistant springs, bearings, bushings, and hinges. C. Balancing Dampers. Low Pressure: Provide balancing dampers at points on supply, return, and exhaust systems where branches are taken from larger ducts as required for air balancing. Refer to Drawings. D. Flexible Connections: Provide, immediately adjacent to equipment in ducts associated with fans and equipment subject to forced vibration. In addition, provide flexible connections where ductwork crosses building expansion joints and where ductwork crosses separations between new and existing construction. PART 3 - EXECUTION 3.01 INSTALLATION A. Install items in accordance with manufacturer's printed instructions and SMACNA standards. B. Locate duct access doors for easy access. Locate doors above accessible ceilings whenever possible. Coordinate locations of ceiling access doors with ceiling installer and with other trades such that conduit and pipe does not prevent or interfere with access to ductwork. Refer to Section 15050 for access door requirements in ceilings and walls.
C. Install combination fire/smoke dampers in accordance with manufacturer's printed installation instructions including provisions for any supplementary framing and blocking of metal or wood studs in drywall partitions. Coordinate requirements for this work with Division-9. Costs of all such supplemental framing shall be borne by this Contractor. Placement of framing units shall remain work of Division-9. D. Mount damper operators control devices, thermometers, and gauges upon extension brackets or devices to prevent interference with insulation or vapor barrier integrity. E. Install flexible connections at furnace coil supply air discharge. F. Provide sheet metal return air/outside air mixing plenum at each furnace coil. **END OF SECTION**