235400_Furnaces.pdf

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FURNACES

SECTION 235400

FURNACES

PART 1 – GENERAL

1.1 SUMMARY

A. This Section includes the following:

1. Propane-fired, condensing furnaces and accessories complete with controls.

2. Air filters.

3. Refrigeration components.

1.2 SUBMITTALS

A. Product Data: Include rated capacities, operating characteristics, furnished specialties, and accessories for each of the following:

1. Furnace.

2. Thermostat.

3. Air filter.

4. Refrigeration components.

B. Operation and maintenance data.

C. Warranty.

1.3 QUALITY ASSURANCE

A. Electrical Components, Devices, and Accessories: Listed and labeled as defined in

NFPA 70, Article 100, by a testing agency acceptable to authorities having jurisdic-tion, and marked for intended use.

B. ASHRAE Compliance: Applicable requirements in ASHRAE 62.1-2004, Section 5 -

"Systems and Equipment" and Section 7 - "Construction and Startup."

C. ASHRAE/IESNA 90.1-2004 Compliance: Applicable requirements in

ASHRAE/IESNA 90.1-2004, Section 6 - "Heating, Ventilating, and Air-

Conditioning."

D. Comply with NFPA 70.

E. All products to be manufactured in the US and comply with the Buy American Act.

1.4 WARRANTY

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A. Special Warranty: Manufacturer's standard form in which manufacturer agrees to re-pair or replace the following components of furnaces that fail in materials or work-manship within specified warranty period:

1. Warranty Period, Commencing on Date of Substantial Completion:

a. Furnace Heat Exchanger: 10 years.

b. Integrated Ignition and Blower Control Circuit Board: Five years.

c. Refrigeration Compressors: 10 years.

d. Evaporator and Condenser Coils: Five years.

PART 2 – PRODUCTS

2.1 GAS-FIRED FURNACES, CONDENSING

A. Available Manufacturers: Subject to compliance with requirements, manufacturers of-fering products that may be incorporated into the Work include, but are not limited to, the following:

B. Manufacturers: Subject to compliance with requirements, provide products by one of the following:

C. Basis-of-Design Product: Subject to compliance with requirements, provide the prod-uct indicated on Drawings Carrier or a comparable product by one of the following:

1. American Standard Companies, Inc.

2. Lennox Industries Inc.

3. Trane.

4. York International Corp.; a division of Unitary Products Group.

D. General Requirements for Gas-Fired, Condensing Furnaces: Factory assembled, piped, wired, and tested; complying with ANSI Z21.47/CSA 2.3, "Gas-Fired Central

Furnaces," and with NFPA 54.

E. Cabinet: Steel.

1. Cabinet interior around heat exchanger shall be factory-installed insulation.

2. Lift-out panels shall expose burners and all other items requiring access for maintenance.

3. Factory paint external cabinets in manufacturer's standard color.

4. Airstream Surfaces: Surfaces in contact with the airstream shall comply with requirements in ASHRAE 62.1-2004.

F. Fan: Centrifugal, factory balanced, resilient mounted, direct drive.

1. Fan Motors: Comply with requirements in Division 23 Section "Common Mo-tor Requirements for HVAC Equipment."

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2. Special Motor Features: Single speed, Premium (TM) efficiency, as defined in

Division 23 Section "Common Motor Requirements for HVAC Equipment," and with internal thermal protection and permanent lubrication.

3. Special Motor Features: Multitapped, multispeed with internal thermal protec-tion and permanent lubrication.

4. Special Motor Features: Electronically controlled motor (ECM) controlled by integrated furnace/blower control. Variable speed control.

G. Type of Gas: Propane.

H. Heat Exchanger:

1. Stainless steel.

I. Burner:

1. Gas Valve: 100 percent safety modulating main gas valve, main shutoff valve, pressure regulator, safety pilot with electronic flame sensor, limit control, trans-former, and combination ignition/fan timer control board.

2. Ignition: Electric pilot ignition, with hot-surface igniter or electric spark igni-tion.

J. Gas-Burner Safety Controls:

1. Electronic Flame Sensor: Prevents gas valve from opening until pilot flame is proven; stops gas flow on ignition failure.

2. Flame Rollout Switch: Installed on burner box; prevents burner operation.

3. Limit Control: Fixed stop at maximum permissible setting; de-energizes burner on excessive bonnet temperature; automatic reset.

K. Combustion-Air Inducer: Centrifugal fan with thermally protected motor and sleeve bearings prepurges heat exchanger and vents combustion products; pressure switch prevents furnace operation if combustion-air inlet or flue outlet is blocked.

L. Furnace Controls: Solid-state board integrates ignition, heat, cooling, and fan speeds;

adjustable fan-on and fan-off timing; terminals for connection to accesso-ries; diagnostic light with viewport. Provide zoned dampers and all associated controls for furnaces, F-1,2,3. Carrier Infinity zoned control damper system or equivalent.

M. Accessories:

1. Combination Combustion-Air Intake and Vent: PVC plastic fitting to combine combustion-air inlet and vent through roof.

2. CPVC Plastic Vent Materials.

a. CPVC Plastic Pipe: Schedule 40, complying with ASTM F 441/F 441M.

b. CPVC Plastic Fittings: Schedule 40, complying with ASTM F 438, socket type.

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c. CPVC Solvent Cement: ASTM F 493.

1) Use CPVC solvent cement that has a VOC content of 490 g/L or less when calculated according to 40 CFR 59, Subpart D (EPA Me-thod 24).

2) Use adhesive primer that has a VOC content of 550 g/L or less when calculated according to 40 CFR 59, Subpart D (EPA Method 24).

3. Condensate pump integral to the unit. Capable of 5 ft of lift at 1 gpm. If integral pump option is not available provide comparable pump by Little Giant or ap-proved equivalent.

N. Capacities and Characteristics:

1. Airflow Configuration: Horizontal.

2. Gas:

a. Type: Propane.

b. Venting Type: Power venter with combustion-air intake.

c. Minimum Efficiency AFUE: 95 percent.

2.2 THERMOSTATS

A. Solid-State Thermostat: Wall-mounting, programmable, microprocessor-based unit with automatic switching from heating to cooling, preferential rate control, seven-day programmability with minimum of four temperature presets per day, vacation mode, and battery backup protection against power failure for program settings.

B. Control Wiring: Unshielded twisted-pair cabling.

1. No. 24 AWG, 100 ohm, four pair.

2. Cable Jacket Color: Blue.

C. Controls shall comply with requirements in ASHRAE/IESNA 90.1-2004, "Controls."

2.3 AIR FILTERS

A. Disposable Filters: 1-inch- (25-mm-) thick fiberglass media with ASHRAE 52.2

MERV rating of 6 or higher in sheet metal frame.

2.4 REFRIGERATION COMPONENTS

A. General Refrigeration Component Requirements:

1. Refrigeration compressor, coils, and specialties shall be designed to operate with

CFC-free refrigerants.

2. Energy Efficiency: Equal to or greater than prescribed by

ASHRAE/IESNA 90.1-2004, "Energy Standard for Buildings except Low-Rise

Residential Buildings."

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B. Refrigerant Coil: Copper tubes mechanically expanded into aluminum fins. Comply with ARI 210/240, "Unitary Air-Conditioning and Air-Source Heat Pump Equip-ment." Match size with furnace. Include condensate drain pan with accessible drain outlet complying with ASHRAE 62.1-2004.

1. Refrigerant Coil Enclosure: Steel, matching furnace and evaporator coil, with access panel and flanges for integral mounting at or on furnace cabinet and gal-vanized sheet metal drain pan coated with black asphaltic base paint.

C. Refrigerant Line Kits: Annealed-copper suction and liquid lines factory cleaned, dried, pressurized with nitrogen, sealed, and with suction line insulated. Provide in standard lengths for installation without joints, except at equipment connections.

1. Flexible Elastomeric: Closed-cell, sponge- or expanded-rubber materials.

Comply with ASTM C 534, Type I, 1/2 inch (13 mm) thick.

D. Refrigerant Piping: Comply with requirements in Division 23 Section "Refrigerant

Piping."

E. Air-Cooled, Compressor-Condenser Unit:

1. Casing: Steel, finished with baked enamel, with removable panels for access to controls, weep holes for water drainage, and mounting holes in base. Provide brass service valves, fittings, and gage ports on exterior of casing.

2. Compressor: Hermetically sealed scroll type.

a. Crankcase heater.

b. Vibration isolation mounts for compressor.

c. Compressor motor shall have thermal- and current-sensitive overload de-vices, start capacitor, relay, and contactor.

d. Two-speed compressor motors shall have manual-reset high-pressure switch and automatic-reset low-pressure switch.

e. Refrigerant Charge: R-410A.

f. Refrigerant: R-410A.

3. Refrigerant Coil: Copper tube, with mechanically bonded aluminum fins, com-plying with ARI 210/240, and with liquid subcooler.

4. Heat-Pump Components: Reversing valve and low-temperature air cut-off thermostat.

5. Fan: Aluminum-propeller type, directly connected to motor.

6. Motor: Permanently lubricated, with integral thermal-overload protection.

7. Low Ambient Kit: Permits operation down to 45 deg F (7 deg C).

8. Mounting Base: Polyethylene.

9. Two-stage cooling controls

10. 14.5 SEER rating when matched with scheduled coil.

PART 3 – EXECUTION

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3.1 INSTALLATION

A. Install gas-fired furnaces and associated fuel and vent features and systems according to NFPA 54.

B. Suspended Units: Suspend from structure using threaded rods, spring hangers, and building attachments. Secure rods to unit hanger attachments. Adjust hangers so unit is level and plumb.

C. Controls: Install thermostats and humidistats at mounting height of 60 inches (1500

mm) above floor.

D. Wiring Method: Install control wiring in accessible ceiling spaces and in gypsum board partitions where unenclosed wiring method may be used. Conceal control wir-ing except in unfinished spaces.

E. Install ground-mounted, compressor-condenser components on 4-inch- (100-mm-) thick, reinforced concrete base; 4 inches (100 mm) larger on each side than unit. Con-crete, reinforcement, and formwork are specified in Division 03 Section "Cast-in-

Place Concrete." Coordinate anchor installation with concrete base.

3.2 CONNECTIONS

A. Gas piping installation requirements are specified in Division 23 Section " Facility Li-quefied-Petroleum Gas Piping." Drawings indicate general arrangement of piping, fit-tings, and specialties. Connect gas piping with union or flange and appliance connec-tor valve.

B. Install piping adjacent to equipment to allow service and maintenance.

C. Vent and Outside-Air Connection, Condensing, Gas-Fired Furnaces: Connect plastic piping vent material to furnace connections and extend outdoors. Terminate vent out-doors with a cap and in an arrangement that will protect against entry of birds, insects, and dirt.

1. Ream ends of pipes and tubes and remove burrs. Bevel plain ends of steel pipe.

2. Remove scale, slag, dirt, and debris from inside and outside of pipe and fittings before assembly.

3. Plastic Piping Solvent-Cement Joints: Clean and dry joining surfaces. Join pipe and fittings according to the following:

a. Comply with ASTM F 402 for safe-handling practice of cleaners, primers, and solvent cements.

b. CPVC Piping: Join according to ASTM D 2846/D 2846M Appendix.

c. PVC Pressure Piping: Join schedule number ASTM D 1785, PVC pipe and PVC socket fittings according to ASTM D 2672. Join other-than-schedule-number PVC pipe and socket fittings according to

ASTM D 2855.

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d. Requirements for Low-Emitting Materials:

1) Use CPVC solvent cement that has a VOC content of 490 g/L or less when calculated according to 40 CFR 59, Subpart D (EPA Me-thod 24).

2) Use PVC solvent cement that has a VOC content of 510 g/L or less when calculated according to 40 CFR 59, Subpart D (EPA Me-thod 24).

3) Use adhesive primer that has a VOC content of 550 g/L or less when calculated according to 40 CFR 59, Subpart D (EPA Method 24).

4. Slope pipe vent back to furnace or to outside terminal.

D. Connect ducts to furnace with flexible connector. Comply with requirements in Divi-sion 23 Section "Air Duct Accessories."

E. Connect refrigerant tubing kits to refrigerant coil in furnace and to air-cooled, com-pressor-condenser unit.

1. Flared Joints: Use ASME B16.26 fitting and flared ends, following procedures in CDA's "Copper Tube Handbook."

2. Soldered Joints: Apply ASTM B 813, water-flushable flux, unless otherwise in-dicated, to tube end. Construct joints according to ASTM B 828 or CDA's

"Copper Tube Handbook," using lead-free solder alloy complying with

ASTM B 32.

3. Brazed Joints: Construct joints according to AWS's "Brazing Handbook," "Pipe and Tube" Chapter, using copper-phosphorus brazing filler metal complying with AWS A5.8.

F. Comply with requirements in Division 23 Section "Refrigerant Piping" for installation and joint construction of refrigerant piping.

G. Complete installation and startup checks and start units according to manufacturer's written instructions.

H. Verify proper operation of capacity control device.

I. Adjust airflow and initial temperature and humidity set points.

J. Set controls, burner, and other adjustments for optimum heating performance and effi-ciency. Adjust heat-distribution features, including shutters, dampers, and relays, to provide optimum heating performance and system efficiency.

K. After completing installation, clean furnaces internally according to manufacturer's written instructions.

L. Install new filters in each furnace within 14 days after Substantial Completion.

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3.3 FIELD QUALITY CONTROL

A. Perform the following field tests and inspections and prepare test reports:

1. Perform electrical test and visual and mechanical inspection.

2. Leak Test: After installation, charge systems with refrigerant and oil and test for leaks. Repair leaks, replace lost refrigerant and oil, and retest until no leaks ex-ist.

3. Operational Test: After electrical circuitry has been energized, start units to confirm proper operation, product capability, and compliance with requirements.

4. Verify that fan wheel is rotating in the correct direction and is not vibrating or binding.

5. Test and adjust controls and safeties. Replace damaged and malfunctioning con-trols and equipment.

B. Verify that vibration isolation and flexible connections properly dampen vibration transmission to structure.

END OF SECTION 235400