DIVISION 15-MECHANICAL PN SECTION DUCTWORK SYSTEMS PART 1 - GENERAL 1.01 SECTION INCLUDES. A. Low, medium and high pressure ductwork.

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1 PART 1 - GENERAL 1.01 SECTION INCLUDES A. Low, medium and high pressure ductwork DEFINITIONS A. Duct Sizes: Inside clear dimensions. B. Low Pressure: 1/2 inch, 1 inch and 2 inch wg, positive or negative. C. Medium Pressure: 3 inch wg, positive or negative. 4 inch wg, positive, 6 inch wg, positive. D. High Pressure: 10 inch wg, positive. E. Class 1: Non abrasive applications SUBMITTALS A. Shop Standards: 1. Submit shop standards for all systems at least four weeks prior to first shop fabrication drawing. 2. Indicate duct fittings, gauges, sizes, welds and configurations. Submit assembly and installation instructions for proprietary mechanical duct connection system. B. Shop Drawings: 1. Show air outlets, inlets, light fixtures, structural elements, lintels, partitions and other elements affecting routing of ductwork. Coordinate air device locations with ceiling installer. Show room numbers, names and column lines. 2. Show all ductwork pieces fitting connections, bottom of ductwork elevations, distance of ductwork to columns and walls, and all ductwork sections and fittings shall be assigned fabrication number. 3. Coordinate proposed installation to provide access for components requiring maintenance. 4. Shop Drawings, Initial Submission: a. Submit drawings individually or in pairs as they are completed

2 b. To avoid delay in review of submittals, do not submit more than two pairs (drawings) within the same review period. 5. Resubmissions: a. Make corrections and revisions required by initial submission. Drawings resubmitted without complete corrections and revisions will be returned without review. b. Identify revisions, other than those required by initial submission, by circling the devices data, duct run or equipment. C. List of exceptions to specifications on a line-by-line basis. Include proposed materials, methods, and cost difference where substitutions are allowed DELIVERY, STORAGE AND HANDLING A. Close open ends of ductwork with temporary covers. PART 2 - PRODUCTS 2.01 BASIC MATERIALS A. Steel: Galvanized sheet, lock-forming quality, G90 finish, ASTM A527. B. Hanger Rod: Steel, galvanized, threaded both ends, threaded one end, or continuously threaded. C. Duct Joint Sealant: United McGill "United Duct Sealer." No substitutions. D. Duct Sleeves, Sealing Collars and Seals: 1. Round Duct Sleeves: Minimum 20 gauge galvanized steel. 2. Square and Rectangular Duct Collars: Minimum 1-1/2 inch x 26 gauge galvanized steel flange. 3. Sealers, Fire Rated Construction: See Division Sealers, Non-Fire Rated Construction: See Division 7. E. Flexible Sleeves: Ventfabrics Inc. "Metaledge Ventglas". No substitutions. 9 inch wide, 30 ounce glass fabric, double coated with neoprene, flame spread rating of 25, 24 gauge galvanized. Secure with one inch wide, galvanized steel bands and 1/8 inch stove bolts 5 inches OC. F. Fasteners: Rivets, bolts or sheet metal screws. Fastener shall match material being fastened

3 2.02 GENERAL REQUIREMENTS A. Drawings indicate general arrangement of work. Carefully examine Drawings and be responsible for proper fit without substantial alteration of indicated layout. Verify dimensions and routing shown with relation to existing construction and work of other trades. Verify locations and interferences prior to fabrication and erection. B. Rigidly brace and reinforce ducts with angles or other structural members of same material. Make internal ends of slip joints lay with flow. Make ducts straight and smooth inside, with joints neatly finished. C. Elbows in Rectangular Ductwork: 1. Square throat elbows larger that 8 inches: double thickness turning vanes. Omit turning vanes from transfer air duct elbows. 2. Securely fasten vanes to runner for quiet, vibration free operation. 3. Square throat elbows 8 inches and smaller; radius elbows. 4. Radius elbows; minimum centerline radius of 1-1/2 times duct width. 5. In parallel flow branches with 8 inch neck and smaller: make turns out of nested fittings with radius elbows. D. Elbows in Round Duct: 1. Elbows Centerline Radius: 1.5 times duct diameter Inch Diameter or Smaller Duct Size: a. 15 and 30 degree elbow: 2 gore segmented. b. 45 degree elbow: Manufactured two-piece stamped sweep. c. 90 degree elbow: 5 gores segmented or manufactured two piece stamped sweep. 3. Larger than 12 Inch Diameter Duct: a. 15 and 30 degree elbow: 2 gore segmented. b. 45 degree elbow: 3 gore segmented. c. 90 degree elbow: 5 gore segmented. 4. Welded Miter Elbow: 30 degree maximum. E. Provide inside collars where registers or grilles are mounted flush to ductwork. Use minimum size collars required to install a controller which will produce uniform air flow over face of register or grille. F. Where ducts are exposed to weather, locate longitudinal seams on bottom of duct and crossbreak top to shed water

4 G. Dissimilar Metals: Make connections using fully gasketed flanges FABRICATION REQUIREMENTS A. Pressure Class: 3 inch negative to 10 inch positive. 1. Duct Construction Standards: SMACNA HVAC. 2. Rectangular Longitudinal Seams: Pittsburgh Lock or continuously welded. 3. Round Longitudinal Seams: Lock type: RL-1 (Spiral), RL-4 (Butt Weld or Lapped and Seam Welded) of RL-5 (Groove Seam). 4. Rectangular Sealed Transverse Joints: Proprietary Joint System for ducts 8 inches and larger. Pocket lock type for ducts smaller than 8 inches. 5. Rectangular Welded Transverse Joints: T-21 (Welded Flange) or T-21a (Reinforced Welded Flange). Tie rods are not permitted in humidifier ducts. 6. Round Sealed Transverse Joints: Proprietary Joint System, RT-1 (Beaded Sleeve), RT-6 (Swedge), or RT-5 (Beaded Crimp) up to 2 inch maximum. 7. Round Welded Transverse Joints: RT-4 (Outside Sleeve) or Welded Flange. 8. Round Fittings: Slip type: pleated or continuously welded stamped or segmented. Continuously welded fittings such as conical tees, 45 degree laterals or wyes should be used for continuously welded systems. 9. Seal Class: A for sealed systems: not applicable for welded systems PROPRIETARY MECHANICAL DUCT CONNECTION SYSTEM A. Manufacturers: 1. Lockformer "T.D.C." 2. Engel "T.D.F." 3. Ward Duct Connection Industries. 4. Ductmate Industries, Inc. "Ductmate". 5. Exxano Corporation "Nexus". 6. Substitutions: None permitted. B. Do not use mechanical connectors on ducts heavier than 16 gauge or lighter than 26 gauge

5 C. Products and Materials: 1. Construction Materials: Same as specified for ductwork. 2. Cleat: 20 gauge. 3. Corner Clips, Bolts and Nuts: 16 gauge clips or 3/8 inch diameter bolts with nuts. 4. Gasket: Tremco #440, Ductmate #440, or Hardcast #1902FR. Use only closed cell neoprene at fire damper break-away joints FLEXIBLE NON-METAL DUCTWORK A. DESIGN STANDARD MANUFACTURER: Manufacturers or model numbers listed are the design standards. Substitutions subject to Division 1 are: 1. Flexible Technologies. 2. Flexaust. 3. Wagner Corp. 4. Unaflex. 5. Thermaflex. 6. Other Substitutions: None Permitted. B. Non-Metallic, Exposed to View in Finished Areas: 1. Type 1: Flexible Technologies Model Spiratube NC-i; neoprene impregnated polyester fabric, enclosed spring steel wire helix, integral liner. 2. Type 2: Flexaust Model Flexadux R-2; PVC welded, reinforced spring steel wire helix, blue. C. Non-Metallic, Concealed and Unfinished Areas: 2.06 ACCESS DOORS 1. Type 3: Thermaflex Insulated type M-KC and non-insulated type S-TL, UL181, Class 1, rated for 6000 fpm velocity, glass fiber cloth, coated spring steel wire helix, 1 inch thick glass fiber insulation with vapor barrier. Use insulated type where required by Section A. DESIGN STANDARD MANUFACTURER: AIR BALANCE INC. Substitutions: Follow Division 1. Ruskin. 2. Cesco

6 3. Other Substitutions: None Permitted. B. Material: Minimum 24 gauge metal, matching material specified for duct. C. Pressure Rating: Suitable for duct pressure classifications shown. D. Sizing: DUCT WIDTH DOOR LENGTH X WIDTH NO. REQUIRED 18 inch and smaller 12 inch x DWZ 1 20 inch to 48 inch 18 inch x 18 inch 1 50 inch and larger 18 inch x 18 inch 2 Note: DWZ = duct width minus 2 inches. E. Hardware 1. Hinges: Wrought steel, zinc plated: brass pins: sized to suit door: minimum two per door. 2. Fasteners: Brass, window sash type; minimum two per door. 3. Pull: Brass, minimum one per door on suction side of fan. F. Reinforce doors with flat or angle iron stiffening frame to avoid racking. Make doors on insulated ductwork of double panel construction with an acceptable type insulated filler not less than 1 inch thick. Frame out duct openings with a continuous reinforcing bar or angle against which door shall close. At insulated ducts, provide an extended metal collar flush with butt face of insulation. Attach gaskets to bar or angle with flameproof adhesive for airtight construction. Attach doors with at least two hinges VOLUME DAMPERS A. Design Standard Manufacturer: Ruskin (models as specified). Substitutions subject to Division 1 are: 1. American Air Warming. 2. Air Balance. 3. Cesco. 4. Other Substitutions: None permitted. B. Rigidly construct to eliminate flutter or vibration; exterior quadrant adjustment with locking nut, elevated platform for insulated ducts and sealed end bearings screwed or riveted to duct. Include open end bearings on ducts beneath elevated platforms to reduce duct leakage

7 C. Splitter dampers are not acceptable as volume dampers. D. Materials: As specified for ductwork unless otherwise noted. E. Round 4 Inch to 20 Inch: 20 gauge frame and blade. Model MDR25. F. Rectangular: 16 gauge frame and blade. Model MD35. Use 6 inch x 6 inch minimum. PART 3 - EXECUTION 3.01 PREPARATION A. Coordinate with concrete, masonry and gypsum wallboard trades as appropriate for through-wall duct sleeves. B. Install through-wall duct sleeves INSTALLATION A. Assemble, mount and seal ductwork systems. Install duct and plenum mounted equipment in accordance with manufacturer's recommendations. B. Suspend ducts securely, so that under conditions of operation, there will be no vibration. C. Provide openings in ductwork where required to accommodate thermometers and controllers. Provide pitot tube openings where required for testing of systems. D. Holes in Ductwork: 1. Where ducts are insulated, neatly cut a 3 inch wide strip of insulation away from the hole site. 2. Drill holes in ducts, casings and plenums not exceeding 12 inches OC in locations as directed by Balancing Agency. 3. Use snap-in plugs for low and medium pressure systems with material gauges of 14 to Reinstall cut away insulation and cover with 4 inch wide duct tape. Identify plug and instrument hole locations of insulated ducts as "test holes" for future reference and use. E. Locate ducts with sufficient space around equipment to allow normal operating and maintenance activities

8 F. Connect ducts to fans with flexible sleeves. G. Connect air inlets and outlet to low pressure ducts with (5 feet maximum length) flexible ductwork. Hold in place with metal strap or clamp. H. Do not use flexible duct to form elbows or turns exceeding 90 degrees. Use rigid metal duct for such applications. Hang flexible ductwork on 30 inch centers with maximum sag of '1 inch per foot. Do not support ducts from ceiling system. I. Do not hang ductwork from metal roof deck where deck is not topped with concrete. Provide supplementary or structural steel in accordance with Division 5. J. During construction, provide temporary closures of metal or taped polyethylene on open ductwork, to prevent construction dust from entering ductwork system. K. Install mechanical duct connection systems in strict conformance with manufacturer's instructions. Overtightening of corner piece nuts and bolts may cause leakage in excess of allowable levels EXISTING CONSTRUCTION A. Where existing duct openings are shown to be closed, seal with gasketed sheet metal panels and sheet metal screws. Panels shall be same gauge and material as existing duct DUCTWORK APPLICATION AND MATERIAL SCHEDULE Notes: DUCTWORK SYSTEM SERVICE Ductwork, indoors MATERIAL (NOTES) Galvanized 1. Continuity welded joints, seams and connections. 2. Continuously welded joints, seams and connections on vertical ducts. For horizontal ducts: Continuously weld joints; continuously weld seams and connections on bottom and sidewall; seal seams and connections on top. PART 4 - MEASUREMENT AND PAYMENT 4.01 All costs for all work indicated in this specification section will be included in the Contractor's lump sum amount, unless indicated otherwise

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