09006 15210.pdf

SECTION 15210

DIVISION 15 – HEATING, VENTILATION AND AIR CONDITIO NING EQUIPMENT

15210 - Page 1 of 7

PART 1 - GENERAL

1.01RELATED DOCUMENTS:

A. Refer to Section 15200 for General Requirements for Mechanical Work.

1.02SCHEDULES ON DRAWINGS:

A. In general, all capacities of equipment and motor and starter characteristics are shown on schedules on the drawings. The capacities shown are minimum capacities. Variations in the characteristics will be permitted only on written approval of the Contracting Officer. Insofar as is possible, all items of the same type (i.e. pumps, fans, etc.) shall be by the same manufacturer. Where instructions on installation are not included on these specifications or on the plans, the manufacturers' instructions shall be followed.

PART 2 - PRODUCTS

2.01PACKAGED AIR CONDITIONING UNITS:

A. General:

1. Units shall be fully packaged, factory assembled, piped, wired, and fully charged with R-22 or R410A refrigerant and oil. Units shall be designed for rooftop installation.

2. Unit casing shall consist of weather-resistant steel cabinet having baked enamel finish. Provide access panels for controls, coil, supply fan, outdoor fan, and compressor. The indoor fan section shall be internally insulated with fireproof glass fiber material. Drip pan shall be provided with drain connections.

B. Compressor/motor shall be hermetically sealed high efficiency with suitable vibration isolation. Internal line break over current and over temperature protection, high and low pressure protection, and crank case heaters shall be provided.

C. Refrigerant circuit shall have independent capillary expansion devices, service pressure ports and refrigerant line filter driers factory installed as standard.

D. Coils shall be constructed of aluminum fins mechanically bonded to seamless copper tube.

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E. Outdoor fan shall be direct driven type, statically and dynamically balanced, draw through configuration. Provide permanently lubricated weatherproof motor with built-in thermal overload protection.

F. Indoor fan shall be belt driven, forward curve centrifugal type. Provide permanently lubricated weatherproof motor with built-in overload protection.

G. Gas heating section shall have a drum and tube heat exchanger design using corrosion resistant steel components. A forced combustion blower shall supply premixed fuel to a single ignited by a pilotless hot surface ignition system. Heating section shall be complete with all the safety devices to lock out the entire unit until manual rest, after three unsuccessful ignition.

H. Provide two inch pleated filters, Farr 30/30 or equal.

I. Provide low ambient controls.

J. Provide anti-short cycle timer.

K. Provide central control panel.

L. Provide manufacturer's roof curb. See detail on drawings.

2.02Infra-Red Radiant Heaters

A. General:

1. Infra-red heaters shall be design certified by the American Gas Association (AGA) and shall comply with current Occupational Safety and Health Act (OSHA) requirements.

2. Infra-red heaters shall be designed to operate without adjustments when burning natural gas.

B. Construction:

1. The heater control housing shall be totally enclosed with and enameled exterior finish.

2. The heaters combustion and radiant emitter tube shall be 4” outside diameter, 16 gauge aluminized steel finished with high emissivity rated, 15210 - Page 3 of 7 corrosion resistant, black coating.

3. The heaters combustion chamber and radiant emitter tube shall incorporate a 4” slip fit connection in which the upstream tube slides into the next tube and is held by a bolted clamp.

4. Reflectors shall be polished aluminum with reflector end caps. Reflectors shall have field adjustable rotation up to 45 degrees each way.

5. The heaters shall utilize a downstream turbulator baffle for maximum efficiency.

6. The heaters shall be factory equipped with a sight glass allowing visual inspection of ignitor and burner operation from the floor.

7. The infra-red tube heaters shall be designed so that outside combustion air can be ducted from the exterior without the use of additional fans. An air intake collar shall be supplied as a part of the burner control assembly to accept a 4” diameter duct.

8. Each heater shall be provided with a 24” stainless steel flex connector and one ½” gas cock.

C. Controls:

1. The heaters shall be equipped with a direct silicon carbide ignition system. Power supplied to each burner shall be 120 volt, single phase.

2. Heater controls shall include two safety differential pressure switches.

3. The heaters control system shall be designed to shut off the gas flow to the main burner in the event either gas supply or power supply interruption occurs.

4. The heaters air flow control system shall provide a 45 second pre-purge prior to initiating burner operation.

2.03CENTRIFUGAL EXHAUST FANS:

A. General:

1. Rooftop exhaust fans shall be centrifugal belt driven type complete with

15210 - Page 4 of 7 backdraft damper and disconnect. The fan wheel shall be centrifugal type with airfoil wheel, constructed of continuously welded heavy gauge steel. The wheel shall be of the non-overloading airfoil centrifugal type.

Wheels shall be statically and dynamically balanced.

2. The fan housing and bearing support shall be constructed of heavy gauge structural steel members to prevent vibration and rigidly support the shaft and bearings. The wheel cone and fan inlet cone shall be carefully matched and shall have precise running tolerances for maximum performance and operating efficiency.

3. Fan performance shall be based on testes coducted in accordance with AMCA Standard 210 test code for air moving devices. All fans shall bear the AMCA Certified Ratings Seal for sound and air performance.

B. Motors:

1. Motors shall be heavy duty ball bearing type, carefully matched to the fan load. Motors and drives shall be mounted on vibrations isolators, out of the airstream. Fresh air for motor cooling shall be drawn into the motor compartment form an area free of discharge contaminants. Motors shall be readily accessible for maintenance.

2. Drives:

3.

4. Drive frame assemblies shall be constructed of heavy gauge steel and mounted on vibration isolators.

5.

6. Bearings:

7. Precision ground and polished fan shafts shall be mounted in permanently sealed, lubricated pillow block ball bearings. Bearings shall be selected for a minimum (L50) life in excess of 200,000 hours at maximum cataloged speed. Drives shall be sized for a minimum of 150% of driven horsepower. Pulleys shall be of the fully machined cast iron type, keyed and securely attached to the wheel and the motor shafts.

Motor pulleys shall be adjustable for final system balancing.

C. Wiring:

1. A disconnect switch shall be factory installed and wired from the fan motor to a junction box installed within the motor compartment. A fan

15210 - Page 5 of 7 conduit chase shall be provided through the curb cap to the motor compartment for ease of installation.

D. Sound Curb:

1. Exhaust fan to set on factory made sound curb. The curb body shall be constructed of heavy gauge galvanized steel. All seams shall be continuously welded. A cant shall be built into the curb to provide a fillet for roof flashing. Wooden nailer strips shall be securely attached to the body and provide a solid foundation for nailing the flashing material to the curb.

2. Rigid fiberglass board of six pound density shall be used for insulation and sound absorption around the interior curb wall.

3. Sound baffle shall be constructed with perforated aluminum sheet die formed into half-sections. Each section shall be filled with fiberglass wool and seamed together. Spring steel wire holding clips shall be secured to aluminum baffle ends to act as formers for the baffles. The assembly shall be rigid, durable section which shall not warp or twist out of shape.

2.04AIR OUTLETS

A. Registers, grilles and diffusers to be factory fabricated, baked enamel finish unless noted otherwise, type and material scheduled. Provide dampers as indicated on Drawings and Frame Style to match ceiling type.

B. In accordance to the certified data of the manufacturer and as indicated on the Drawings, outlets shall perform quietly and effectively. After the system is in operation, if excessive noises are noticeable in the ventilated spaces due to improper operation of outlet, reinstall at no additional cost to the Owner.

C. On flanged outlets, provide sponge-rubber gasket between flange and wall or ceiling.

D. Acceptable manufacturers: Krueger, Tuttle & Bailey, Carnes, Nailor, or Titus.

2.05EVAPORATIVE COOLING UNITS

General:

A. Evaporative cooler assembly shall consist of a unit cabinet, fan, motor, drive, evaporative pads, pump, piping, and automatic fill system. Size, type, and

15210 - Page 6 of 7 capacity shall be as scheduled on Drawings.

B. Blower assembly shall consist of forward curved, double width, double inlet dynamically balanced centrifugal fan, solid shaft, belt drive, and self-aligning bronze oil-impregnated field-lubricated bearings.

C. The entire unit, including the cabinet, blower housing and wheel shall be constructed of heavy gage hot-dipped galvanized steel. The cabinet shall be finish painted inside and out with baked polyester enamel. The water reservoir shall be die formed, welded and soldered seam construction. Water troughs shall be fully visible and adjustable to assure even wetting for each evaporative pad.

D. Louvers and pads shall be held securely in place and both shall be removable without the use of tools. Pad holders shall prevent pad sagging for life of the cooler.

E. Evaporative filter media shall be 12" deep Celdek.

F. The water pump shall be a product of the cooler manufacturer, designed especially to match the cooler capacity. Pump shall have high-impact corrosion-resistant plastic housing, stainless steel shaft with water stop disc, self-aligning permanently lubricated bearings and broad base. The pump shall be capable of running dry without damage. Provide molded plastic inlet screens to surround the pump base.

G. Water distribution piping shall be copper or plastic. Each pad shall be provided with a sufficient number of discharge nozzles to assure full coverage of distribution trough. Provide an integral bleed kit and discharge as indicated on Drawings.

H. Water make-up for the water reservoir shall be controlled with a float valve assembly consisting of a noncorrosive float and seat fitted for compression connection. Include related tubing and overflow pipe.

I. Motors shall be single speed, of the continuous duty open drip-proof type designed especially for evaporative cooler service and shall be mounted in the uppermost part of the cabinet for minimum exposure to water. Motor mount shall be designed such that belt tension may be readily adjusted by positive mechanical means. Motor pulley shall be heavy duty, variable pitch type.

J. Unit shall be shipped completely assembled and shall be factory tested with

15210 - Page 7 of 7 the motor installed and operated prior to shipment.

PART 3 - EXECUTION

3.01MANNER OF PERFORMING WORK:

A. Coordinate location of piping, ductwork, sleeves, inserts, hangers and equipment for this work with other trades.

B. All materials and equipment shall be installed in accordance with the approved recommendations and guidelines as issued by the respective manufacturers to conform with contract documents. The installation shall be accomplished by workmen skilled in the trades involved.

3.02SERVICE CONNECTIONS:

A. Fan coil units shall be equipped with required valves, vents, drain valves and safety devices and connected to piping systems and electrical services in a neat workmanlike manner.

3.03GUARANTEE/WARRANTY:

A. See Division 1 and Section 15210 paragraph 3.09 for Guarantee and Warranty requirements.

END OF SECTION