S06 - Spec Section 23 81 00.pdf

02-11

23 81 00-1

SECTION 23 81 00

DECENTRALIZED UNITARY HVAC EQUIPMENT

PART 1 - GENERAL

1.1 DESCRIPTION

A. This section specifies self-contained, and through-the-wall packaged terminal air conditioners.

B. Definitions:

1. Energy Efficiency Ratio (EER): The ratio of net cooling capacity is

Btu/h to total rate of electricity input in watts under designated operating conditions (Btu hour/Watt).

2. Seasonal Energy Efficiency Ratio (EER): The ratio of the total cooling output of an air conditioner during its normal annual usage period for cooling in Btu/h divided by total electric energy input in watts during the same period (Btu hour/Watt).

3. Unitary: A Unitary Air Conditioner consists of one or more factory-made assemblies which normally include an evaporator or cooling coil, a compressor and condenser combination, and may include a heating function as well.

4. Where such equipment is provided in more than one assembly the separated assemblies are to be designed to be used together and the requirements of rating are based upon use of matched assemblies.

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 05 41, NOISE and VIBRATION CONTROL FOR HVAC PIPING and

EQUIPMENT: Requirements for different types of vibration isolators and noise ratings in the occupied areas.

C. Section 23 07 11, HVAC and BOILER PLANT INSULATION: Requirements for piping insulation.

D. Section 23 23 00, REFRIGERANT PIPING: Requirements for refrigerant pipes and fittings.

1.3 QUALITY ASSURANCE

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

B. Safety Standards: ASHRAE Standard 15, Safety Code for Mechanical

Refrigeration.

“ACCOMPANYING AMENDMENT 36C25220B0026 – 0003”

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1.4 SUBMITTALS

A. Submit in accordance with specification Section 01 33 23, SHOP

DRAWINGS, PRODUCT DATA, and SAMPLES

B. Manufacturer’s literature and data:

1. Sufficient information, including capacities, pressure drops and piping connections clearly presented, shall be included to determine compliance with drawings and specifications for units noted below:

a. Unitary air conditioners:

1) Self-contained through-the-wall packaged air conditioning units

2. Unit Dimensions required clearances, operating weights accessories and start-up instructions.

3. Electrical requirements, wiring diagrams, interlocking and control wiring showing factory installed and portions to be field installed.

4. Mounting and flashing of the roof curb to the roofing structure with coordinating requirements for the roof membrane system.

C. Certification: Submit proof of specified ARI Certification.

D. Performance Rating: Submit catalog selection data showing equipment ratings and compliance with required sensible-to-heat-ratio, energy efficiency ratio (EER), and coefficient of performance (COP).

E. Operating and Maintenance Manual: Submit three copies of Operating and

Maintenance manual to Resident Engineer three weeks prior to final inspection.

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.

B. Federal Specifications (Fed. Spec.):

A-A-50502-90............ Air conditioner (Unitary Heat Pump) Air to Air

(3000-300,000 Btu)

C. Military Specifications (Mil. Specs.):

MIL-PRF-26915D-06.......Primer Coating, for Steel Surfaces

D. Air-Conditioning, Heating, and Refrigeration Institute (AHRI):

210/240-08..............Performance Rating of Unitary Air-Conditioning and Air-Source Heat Pump Equipment

270-08..................Sound Rating of Outdoor Unitary Equipment

310/380-04..............Standard for Packaged Terminal Air-Conditioners and Heat Pumps (CSA-C744-04)

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340/360-07..............Performance Rating of Commercial and Industrial

Unitary Air-Conditioning and Heat Pump

Equipment

520-04..................Performance Rating of Positive Displacement

Condensing Units

E. Air Movement and Control Association (AMCA):

210-07..................Laboratory Methods of Testing Fans for

Aerodynamic Performance Rating (ANSI)

410-96..................Recommended Safety Practices for Users and

Installers of Industrial and Commercial Fans

F. American National Standards Institute (ANSI):

S12.51-02(R2007)........Acoustics - Determination of Sound Power Levels of Noise Sources Using Sound Pressure -

Precision Method for Reverberation Rooms (same as ISO 3741:1999)

G. American Society of Heating, Refrigerating, and Air-Conditioning

Engineers (ASHRAE):

2008 Handbook...........HVAC Systems and Equipment

15-10...................Safety Standard for Refrigeration Systems

(ANSI)

H. American Society of Testing and Materials (ASTM):

B117-09.................Standard Practice for Operating Salt Spray

(Fog) Apparatus

I. American Society of Civil Engineers (ASCE)

ASCE 7-10...............Minimum Design Loads for Buildings and Other

Structures

J. National Electrical Manufacturer's Association (NEMA):

MG 1-09 (R2010).........Motors and Generators (ANSI)

ICS 1-00 (R2005, R2008).Industrial Controls and Systems: General

Requirements

K. National Fire Protection Association (NFPA) Publications:

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

Conditioning and Ventilating Systems

PART 2 - PRODUCTS

2.1 SELF-CONTAINED THROUGH THE WALL AIR CONDITIONERS- BASIS OF DESIGN –

LIEBERT INTERCOOL2 AIR COOLED CRAC MINIMUM 3 TON

A. Description: Factory assembled and wired consisting of the following:

1. Cabinet.

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2. Compressor.

3. Evaporator blower.

4. Evaporator coil,

5. Integral air-cooled condenser.

6. Electric-resistance heating coil

7. Air filters.

8. Controls.

9. Full charge of refrigerant.

B. Cabinet Frame and Panels: Structural-steel frame with galvanized-steel panels with baked-enamel finish in color selected by Architect, and with access doors or panels.

1. Insulation: (1/2-inch) thick, neoprene coated aluminum foil faced glass fiber on cabinet interior and control panel.

2. Drain Pan: Stainless steel insulated complying with ASHRAE 62.1-

2007.

3. Isolation: Spring isolators for mounting under base of unit, with minimum static deflection of 25 mm (1 inch).

4. Discharge Plenum: Cabinet extension with duct openings for supply and return air

5. Corrosion-Resistant Treatment: Phenolic coating on unit interior and exterior.

6. Airstream Surfaces: Surfaces in contact with the airstream shall comply with requirements in ASHRAE 62.1-2007.

C. Evaporator Blower: Galvanized steel, double-width, double-inlet, centrifugal fan; statically and dynamically balanced. Direct drive, with fan mounted on permanently lubricated bearings and having cast-iron or steel sheaves, dynamically balanced, bored to fit shafts and keyed. Motor sheaves shall be variable and adjustable pitch selected so required rpm are obtained when set at middle position. Fan and motor shall be resiliently mounted with ratings as recommended by the manufacturer with a minimum of one and one-half times nameplate rating of motor. Bearings shall be grease lubricated with grease lines extended to exterior of unit.

D. Fan Motors: Comply with requirements in Section 23 05 12, GENERAL MOTOR

REQUIREMENTS FOR HVAC and STEAM GENERATION EQUIPMENT and shall be multi-speed, PSC type open dripproof totally enclosed fan cooled, premium efficiency.

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E. Compressor hermetically sealed, scroll, 3600 rpm maximum, and resiliently mounted with positive lubrication and internal motor protection. Furnish each compressor with independent refrigeration circuits.

F. Evaporator Coil: Direct-Expansion Coil: Seamless copper tubes expanded into aluminum fins with interlaced circuiting:

1. Corrosion-Resistant Treatment: Phenolic coating applied with multiple dips and baked.

G. Refrigerant Circuits: A separate circuit for each compressor, with externally equalized thermal-expansion valve with, filter-dryer, high-pressure relief valve, and charging valves.

H. Refrigerant Line Kits: Annealed-copper suction and liquid lines that are factory cleaned, dried, pressurized, and sealed; insulated suction line; flared fittings at evaporator end, no fitting at condenser end;

and service valves for both suction and liquid lines.

I. Integral Air-Cooled Condenser for Units 52.8 kW (15 tons) and Smaller.

Factory assembled and tested; consisting of condenser coil, fans and motors, and cabinet:

1. Condenser Coil: Aluminum-fin copper tube with integral subcooler;

leak tested to 2930 kPa (425 psig).

2. Low Ambient Control: Cycles fans to permit operation down to minus

18 deg C (0 deg F).

J. Refrigeration System: Factory assembled and tested, and pre-charged with refrigerant; and consisting of piping and accessories connecting compressor, evaporator coil, and condenser coil, and including the following:

1. Expansion valve with replaceable thermostatic element.

2. High-pressure switch.

3. Low-pressure switch.

4. Thermostat for coil freeze-up protection during low-ambient temperature operation or loss of air.

5. Low-ambient switch.

6. Brass service valves installed in discharge and liquid lines.

7. R-407C refrigerant unless otherwise indicated.

K. Terminate suction and liquid refrigerant piping with service valves within unit.

L. Coil Guard: Painted galvanized steel with louvered grilles.

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M. Corrosion-Resistant Treatment: Phenolic coating applied in multiple dips and baked. See paragraph 2.1.D above.

N. Heating Coil:

1. Single Stage Electric-Resistance Heating Coil: Helical, nickel-chrome, resistance-wire heating elements with refractory ceramic support bushings; automatic-reset thermal cutout; built-in magnetic contactors; manual-reset thermal cutout; airflow proving device; and one-time fuses in terminal box for overcurrent protection.

O. Air Filters:

1. Disposable Filters: 50 mm (2 inch) thick, glass-fiber, pleated MERV

7 panel filters.

2. Filter Efficiency: MERV rating as specified above according to

ASHRAE 52.2.

3. Air-Pressure Switch: Indicates dirty filters.

P. ECONOMIZER:

The economizer allows outside air to be introduced into the space through the evaporator filter when conditions are favorable for economizer cooling. An air damper and spring return, direct drive actuator are automatically controlled by an enthalpy control and mixed air sensor. Mechanical cooling and economizer operation do not operate simultaneously.

Q. Controls:

1. Control Package: Factory wired, including contactor, high- and low-pressure cutouts, internal-winding thermostat for compressor, control-circuit transformer, and noncycling reset relay.

2. Time-Delay Relay: Five-minute delay to prevent compressor cycling.

3. Adjustable Thermostat: Remote to control the supply fan, compressor, condenser; or electric-resistance heating coil.

4. System Selector Switch: Off-heat-auto-cool.

5. Fan Control Switch: Auto-on.

6. Time Clock: Cycle unit on and off.

7. Microprocessor Control Panel: Control unit functions, including refrigeration and safety controls, supply-fan motor speed, compressors, air-cooled condenser, cooling tower pump, modulating hot-water coil valve, modulating, steam coil valve and multi-step, 23 81 00-7 electric-resistant heating coil. Time-of-day control shall cycle unit on and off Night-heat and morning warm-up cycle.

8. DDC Interface: Controls shall interface with the BMS system. Provide open protocol BACnet interface.

9. Panel-mounted control switch shall operate unit in remote or local control mode, or to stop or reset.

10. Panel-mounted indication of the operating status system diagnostics and safety alarms, supply-air temperature set point, zone heating-temperature set point, supply-air pressure set point, economizer minimum position set point, supply-air pressure, and high-limit set point. Time-of-day control shall cycle unit on and off and night-heat and morning warm-up cycle.

PART 3 EXECUTION

3.1 INSTALLATION

A. Install units level and plumb maintaining manufacturer’s recommended clearances and tolerances.

3.2 CONNECTIONS

A. Verify condensate drainage requirements.

B. Install condensate drain, minimum connection size, with trap and indirect connection to nearest roof drain or area drain.

C. Ground equipment and install power wiring, switches, and controls for self contained and split systems.

3.3 FIELD QUALITY CONTROL

A. Perform tests and inspections and prepare test reports.

B. Tests and Inspections: After installing units and after electrical circuitry has been energized, test units for compliance with requirements. Inspect for and remove shipping bolts, blocks, and tie-down straps. After electrical circuitry has been energized, start units to confirm proper motor rotation and unit operation. Test and adjust controls and safeties. Replace damaged and malfunctioning controls and equipment. Remove and replace malfunctioning units and retest as specified above.

3.4 INSTRUCTIONS

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

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3.5 STARTUP AND TESTING

The VA Staff will observe startup and contractor testing of selected equipment. Coordinate the startup and contractor testing schedules with the COR . Provide a minimum of 7 days prior notice.

3.6 DEMONSTRATION AND TRAINING

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

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