GAS FIRED FURNACE SPECS - 192026 - 23 54 00 Gas Fired Furnaces Specifications.pdf

Project No. YAQF-192026 23 54 00-1

SECTION 23 54 00 - GAS FIRED FURNACES

PART 1 - GENERAL

1.1 DESCRIPTION:

A. This section includes specifications for gas fired furnaces.

1.2 APPLICABLE PUBLICATIONS:

A. The publications listed below form a part of this specification to the extent referenced.

The publications are referred in the text by basic designation only.

AGA American Gas Association ANSI Z21.64 Direct Vent Central Furnaces ANSI B16.3 Malleable Iron Threaded Fittings ASTM A53 Pipe, Steel, Black and Hot-Dipped, Zinc Coated Welded and Seamless GAMA Gas Appliance Manufacturers Association NEC National Electrical Code SMACNA Sheet Metal and Air Conditioning Contractors' National Association ()

1.3 SUBMITTALS:

A. Include specific manufacturer and model numbers, equipment identification corresponding to project drawings and schedules, dimensions, capacities, materials of construction, ratings, weights, power requirements, and wiring diagrams, filter information and information for all accessories.

1.4 WARRANTY:

A. Furnace primary and secondary heat exchangers warranted for 20-years under normal use and maintenance. Remainder of furnace components warranted for 10-yearse of start-up.

PART 2 - PRODUCTS

2.1 FURNACES:

A. Direct vent, sealed combustion, two–stage condensing type AGA certified for use with natural gas. Minimum annual fuel utilization efficiency (A.F.U.E.) of 96%. All ratings are to be certified by GAMA. All wiring shall comply with the National Electrical Code.

B. All furnaces shall be ENERGY STAR® qualified with the following features:

1. 20-gauge steel cabinet casing with baked on urethane base coat and polyester top coat finish. Insulate cabinet fully with foil faced fiberglass insulation.

2. Construct primary heat exchanger of aluminized steel. Construct secondary heat exchanger of stainless steel with aluminum fins.

3. Aluminized steel multi-port in-shot burner with hot surface ignition, approved for vertical or sidewall venting. Ignitors shall be Silicon Nitride type.

4. AGA listed gas controls including manual main shut-off valve, double automatic gas valves for redundancy and gas pressure regulator.

C. Blowers: Centrifugal type blower fan statically and dynamically balanced with variable speed, constant torque, and direct-drive ECM blower motor. Provide low energy induced draft blower for heat exchanger pre-purge and combustion gas venting.

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D. Internal Controls: Provide solid state integral control unit with all necessary controls and relays including but not limited to:

1. Pressure switch for airflow of flue products through furnace and out vent system

2. Rollout switch with manual reset to prevent over-temperature in burner area

3. Electronic flame sensor

4. Blower access safety interlock

5. Timed blower start after main burners ignite

6. Factory installed 24-volt transformer for controls and thermostat

7. LED’s to indicate status and to aid in troubleshooting

2.2 COOLING COIL:

A. Provide unit with factory fabricated matching cased "A" configuration cooling coil for up-flow units and "V" configuration cooling coil for down-flow units.

1. Minimum ½-inch O.D. seamless copper tubing mechanically bonded to heavy ripple edged aluminum fins with thermal expansion valve, holding charge and copper tube stubs for field piping.

2. Non-corrosive stainless steel or polymer drain pan with ¾-inch NPT drain connection.

3. 20-gauge steel Coil casing with baked enamel finish and fiberglass insulation.

2.3 DUCTWORK:

A. Contractor is expected to accomplish all necessary ductwork revisions required to accomplish connection of the new furnace and coiling coil to existing heating system.

Existing duct by-pass between supply and return air plenums shall be removed. Cap and seal ductwork and provide insulation board to match existing conditions.

B. All sheet metal used for construction of duct shall be minimum 24-gauge conforming to ASTM A 653 galvanized steel sheet of lock forming quality.

C. Duct Sealant: Manufacturer: 3M 800, 3M 900, H.B. Fuller/Foster, Hardcast, Hardcast Peal & Seal, Lockformer cold sealant, Mon-Eco Industries, United Sheet Metal, or approved equal. Silicone sealants are not allowed in any type of ductwork installation.

D. Semi-Rigid Fiberglass Insulation: Minimum nominal density of 3-lbs. per cu. ft., thermal conductivity of not more than 0.28 at 75-degrees F mean temperature, minimum compressive strength of 25-PSF at 10% deformation. Furnish with Foil Scrim Kraft All Service Jacket (FSK).

2.4 PARTICULATE AIR FILTRATION:

A. Use 5-inch thick filter having pleated panels, 100% synthetic, self-supported media fully bonded and sealed in cardboard frame. Filters shall match existing 5-inch deep filters the Government has in stock. The use of custom or uniquely sized filters specific to one manufacturer will not be accepted.

B. Media nominal rating to be 500-FPM face velocity, 0.20-inch WG initial resistance, 1.0-inches WG recommended final resistance., Average capture of filter media shall be 90 92% with a minimum MERV rating of 7.

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C. Side Access Filter Housings: Galvanized steel body with aluminum or galvanized steel filter mounting tracks. Tracks and access doors to have gaskets to minimize air by-pass around the filters.

1. Filter housings shall be fabricated and sized to meet the requirements of the existing

5-inch deep filters the Government has in stock.

2.5 THERMOSTATIC CONTROL:

A. Contractor shall utilize existing thermostats for control of furnaces and air conditioning system.

2.6 NATURAL GAS SYSTEM:

A. Type E or S pipe material is required per ANSI B31.9.

B. Pipe and Fittings: 2-inch and Smaller: ASTM A53, type E or S, standard weight

(schedule 40) black steel pipe with ASTM A197/ANSI B16.3 class-150 black malleable iron threaded fittings or ASTM A234 grade WPB/ANSI B16.9 standard weight, seamless, carbon steel weld fittings.

C. Shut-Off Valves: Valves 2-inch and smaller shall be a ball valve, bronze body, threaded ends, chrome-plated bronze or stainless steel ball, full or conventional port, teflon seat, blowout-proof stem, two-piece construction, suitable for 150-psig working pressure, U.L.

listed for use as natural gas shut-off.

D. Unions and Flanges: 2" and Smaller: ASTM A197/ANSI B16.3 malleable iron unions with brass seats. Use black malleable iron on black steel piping. Use unions of a pressure class equal to or higher than that specified for the fittings of the respective piping service but not less than 250-psi.

E. Pipe Hangers: Sizes ½-inch through 2-inch: Carbon steel, adjustable, clevis, black finish. Anvil figure 65 or 260. Utilizing steel hanger rods that are threaded both ends, threaded one end, and continuous threaded, black finish.

2.7 ELECTRICAL WIRE:

A. Single conductor insulated wire 90-degree C. Insulation: Type THHN/THWN-2, XHHW-2 insulation.

PART 3 - EXECUTION

3.1 INSTALLATION:

A. Install units as shown on plans, as detailed and according to the manufacturer’s installation instructions.

B. Additional Work Building 301: Terminate and remove electrical service to existing electric furnace, remove abandoned wiring to source of supply. Provide new 20-amp circuit and disconnect to new gas furnace for accommodating new construction.

1. Provide new natural gas supply from new furnace to the gas meter. NOTE: Meter may or may not be installed at the time of this scheduled work.

C. Additional Work Building 318: Each gas pressure reducing valve vent and/or relief valve vent shall be provided with new piping, run separately to a point outside of the building, terminated with a screened vent cap, and located according to gas utility regulations.

Work required for nine (9) reducing regulators.

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3.2 FURNACE INSTALLATIONS:

A. Install on minimum 2-inch thick concrete housekeeping pad, steel stand or suspend unit from structure as required per the site conditions.

B. Pipe combustion and air conditioning condensate to nearest floor drain.

C. Provide all natural gas connections from new furnace to existing systems.

D. Provide all electrical connections from new furnace to existing service disconnect switch.

E. Provide schedule 40 PVC, ASTM D1785 combustion air and vent piping and fittings with solvent welded joints as indicated on the drawings. Terminate as recommended by the furnace manufacturer. The use of foam core PVC is not allowed. Furnaces will installed in either a direct-vent (2-pipe) application or a non-direct vent (1-pipe) application as installations conditions require.

3.3 DUCTWORK INSTALLATION:

A. Fabricate and install ductwork in accordance with SMACNA recommendations sizes.

Locate ducts and filter housings with sufficient space around equipment to allow normal operating and maintenance activities.

B. Increase duct sizes gradually, divergence upstream of equipment shall not exceed 30-degrees; convergence downstream shall not exceed 45-degrees.

C. Duct Sealant: Install sealants in strict accordance with manufacturer's recommendations, paying special attention to temperature limitations. Allow sealant to fully cure before pressure testing of ductwork, or before startup of systems.

D. Insulation: Repaired or patched insulation shall be installed with smooth and even surfaces. Poorly fitted joints or use of filler in voids will not be accepted. Provide neatly beveled and coated terminations at all uninsulated fittings, or at other locations where insulation terminates.

3.4 ERECTION OF GAS PIPING:

A. Install all piping parallel to building walls and ceilings and at heights which do not obstruct any portion of a window, doorway, stairway, or passageway. Where interferences develop in the field, offset or reroute piping as required to clear such interferences.

B. Provide anchors, expansion joints, swing joints and/or expansion loops so that piping may expand and contract without damage to itself, equipment, or building.

C. Shut-Off Valves: Provide a new shut-off valve at each appliance or verify existing meets the requirements specified herein.

D. Threaded Pipe Joints: Use a Teflon based thread lubricant or Teflon tape when making joints; no hard setting pipe thread cement or caulking will be allowed.

E. Hangers for Steel Pipe: Piping shall be supported from the building structure;

independently from ductwork and all other trades. Place a hanger within 12-inches of each horizontal elbow, valve, or similar piping specialty item. Space hangers for steel pipe ½-inch through 1¼-inch in diameter at a maximum spacing of 6’-6”.

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3.5 GENERAL WIRING METHODS:

A. All wire and cable shall be installed in conduit.

B. Do not use wire smaller than 12-AWG for power circuits.

C. All relays, transformers and controls are to be in enclosures.

3.6 CONSTRUCTION VERIFICATION

A. Contractor is responsible for construction verification procedures for each furnace and related components that are provided in accordance with the attached Construction Verification sections:

1. CV - 23 41 00 Filter Racks

2. CV - 23 54 00 Gas Fired Furnaces

END OF SECTION