238200.pdf

Parking Garage Project Number 693-222 Department of Veterans Affairs Wilkes-Barre, Pennsylvania

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SECTION 23 82 00 - CONVECTION HEATING AND COOLING UNITS

PART 1 - GENERAL

1.1 DESCRIPTION

Unit heaters and cabinet unit heaters.

1.2 RELATED WORK

A. Section 23 05 11, COMMON WORK RESULTS FOR HVAC: General mechanical requirements and items, which are common to more than one section of Division 23.

B. Section 23 31 00, HVAC DUCTS and CASINGS: Ducts and flexible connectors.

C. Section 23 05 93, TESTING, ADJUSTING, and BALANCING FOR HVAC: Flow rates adjusting and balancing.

1.3 QUALITY ASSURANCE

Refer to Paragraph, QUALITY ASSURANCE, in Section 23 05 11, COMMON WORK

RESULTS FOR HVAC.

1.4 SUBMITTALS

A. Submit in accordance with Section 01 33 23, SHOP DRAWINGS, PRODUCT DATA, and SAMPLES.

B. Manufacturer's Literature and Data:

1. Unit heaters.

2. Cabinet unit heaters.

C. Certificates:

1. Compliance with paragraph, QUALITY ASSURANCE.

2. Compliance with specified standards.

D. Operation and Maintenance Manuals: Submit in accordance with paragraph, INSTRUCTIONS, in Section 01 00 00, GENERAL REQUIREMENTS.

E. Completed System Readiness Checklists provided by the Commissioning Agent and completed by the contractor, signed by a qualified technician and dated on the date of completion, in accordance with the requirements of Section 23 08 00 COMMISSIONING

OF HVAC SYSTEMS.

1.5 APPLICABLE PUBLICATIONS

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

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

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B. American National Standards Institute / Air Conditioning, Heating and Refrigeration

Institute (ANSI/AHRI):

440-08 ...................................Performance Rating of Room Fan Coils

National Fire Protection Association (NFPA):

90A-09 ...................................Standard for the Installation of Air Conditioning and

Ventilating Systems

70-11 .....................................National Electrical Code

C. Underwriters Laboratories, Inc. (UL):

181-08 ...................................Standard for Factory-Made Air Ducts and Air Connectors

1995-05 .................................Heating and Cooling Equipment

1.6 GUARANTY

In accordance with FAR clause 52.246-21

PART 2 - PRODUCTS

2.1 UNIT HEATERS

A. General: Horizontal or vertical discharge type for steam, hot water or electric heating medium, as indicated.

B. Casing: Steel sheet, phosphatized to resist rust and finished in baked enamel. Provide hanger supports.

C. Fan: Propeller type, direct driven by manufacturer's standard electric motor. Provide resilient mounting. Provide fan guard for horizontal discharge units.

D. Discharge Air Control:

1. Horizontal discharge: Horizontal, adjustable louvers.

2. Vertical discharge: Radial louver diffuser.

E. Electric Units: UL listed, factory wired to terminal strips for field connection of power and control wiring.

1. Heating elements: Nickel chromium alloy resistance wire embedded in a magnesium oxide insulating refractory and sealed in corrosion resisting metallic sheath with fins.

Three phase heaters shall have balanced phases.

2. Thermal cutout: Manual reset type, which disconnects elements, and motor in the event normal operating temperatures are exceeded.

3. Magnetic contactor: Factory installed with low voltage relay for remote pilot duty thermostat operation.

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F. Controls: Provide factory installed unit mounted line voltage electric space thermostats to control the unit fan and heater.

2.2 CABINET UNIT HEATERS

A. General: Vertical or horizontal type for steam, hot water or electric heating medium, as indicated.

B. Cabinet: Not less than 1.3 mm (l8 gage) steel with front panel for vertical units and hinged front panel for horizontal units. Finish on exposed cabinet shall be factory-baked enamel in manufacturer's standard color as selected by the Architect. Provide 76 mm

(3-inch) high sub-base for vertical floor mounted units.

C. Fan: Centrifugal blower, direct driven by a single phase, two-speed, electric motor with inherent overload protection. Provide resilient motor/fan mount.

D. Filter: Manufacturer's standard, one inch thick, throwaway type MERV 7 filters.

E. Electric Coil: Spiral sheath or finned-tube construction with Cal-rod resistance elements in aluminum tubes. Units shall be UL listed and factory wired with unit mounted heat switch, magnetic contactors, high temperature cutout safety control, and fan override thermostat.

F. Controls: Provide factory installed unit mounted line voltage electric space thermostats to control the unit fan and heater.

2.5 WALL-MOUNTED UNIT HEATER

A. General: Electric heat, fan driven, thermostatic control, UL listed.

B. Enclosure:

1. Wall box: Not less than 1.3 mm (l8 gage) steel, recessed type.

2. Ribbed 1.6 mm (l6 gage) steel front cover.

3. Closely spaced discharge louvers.

4. Concealed screws for locking trim frame to front cover.

5. Finished in baked enamel of manufacturer’s standard color with satin finish anodized aluminum trim frame.

C. Heating Elements: Steel sheath enclosed finned-tube type.

D. Integral Controls:

l. Two-pole terminal block.

2. Built-in fan delay switch.

3. Automatic reset line voltage internal thermal overheats protection.

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4. Built-in thermostat comfort control with adjustment range between -1 to 32 degree C

(30-90 degrees F), and manually set "No Heat" position; tamper resistant adjustment by inserting screwdriver through front cover louvers.

PART 3 - EXECUTION

3.1 INSTALLATION

A. Work shall be installed as shown and according to the manufacturer’s diagrams and recommendations.

B. Handle and install units in accordance with manufacturer's written instructions.

C. Support units rigidly so they remain stationary at all times. Cross-bracing or other means of stiffening shall be provided as necessary. Method of support shall be such that distortion and malfunction of units cannot occur.

D. Install fiberglass blanket insulation with a minimum R value of 8 above hydronic radiant panels.

3.2 OPERATIONAL TEST

Refer to Section 23 05 11, COMMON WORK RESULTS FOR HVAC.

3.5 DEMONSTRATION AND TRAINING

A. Provide services of manufacturer’s technical representative for two hours to instruct VA personnel in operation and maintenance of units.

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