Attachment 14 - updated section 237433 Dedicated Outside Air System.pdf

SOLICITATION NO:____________________

CONTRACT NO:_______________________

DEDICATED OUTSIDE AIR SYSTEM 237433-1

SECTION 237433 – DEDICATED OUTSIDE AIR SYSTEM

PART 1: GENERAL

1.01 SECTION INCLUDES

A. Indoor Air Handling Units.

1.02 REFERENCES

A. AFBMA 9 - Load Ratings and Fatigue Life for Ball Bearings.

B. AMCA 99 - Standards Handbook.

C. AMCA 210 - Laboratory Methods of Testing Fans for Rating Purposes.

D. AMCA 300 - Test Code for Sound Rating Air Moving Devices.

E. AMCA 500 - Test Methods for Louver, Dampers, and Shutters.

F. AHRI 410 - Forced-Circulation Air-Cooling and Air-Heating Coils.

G. AHRI 430 - Central-Station Air-Handling Units.

H. AHRI 435 - Application of Central-Station Air-Handling Units.

I. ASTMB117 - Standard Practice for Operating Salt Spray Apparatus.

J. NEMA MG1 - Motors and Generators.

K. NFPA 70 - National Electrical Code.

L. SMACNA - HVAC Duct Construction Standards - Metal and Flexible.

M. UL 723 - Test for Surface Burning Characteristics of Building Materials.

N. UL 900 - Test Performance of Air Filter Units.

O. UL 1995 - Standard for Heating and Cooling Equipment.

P. UL 94 - Test for Flammability of Plastic Materials for Parts in Devices and Appliances.

Q. IBC 2000, 2003 - International Building Code.

R. NFPA 90A - Standard for the Installation of Air Conditioning and Ventilating Systems.

S. NFPA 5000 - Building Construction and Safety Code.

T. ASHRAE 90.1 Energy Code.

U. AHRI Standard 1060 - Rating Air-to-Air Heat Exchangers for Energy Recovery Ventilation

Equipment.

V. GSA 2003 Facilities Standard - 5.9 HVAC Systems and Components.

1.03 SUBMITTALS

A. Shop Drawings: Indicate assembly, unit dimensions, weight loading, required clearances, construction details, field connection details, and electrical characteristics and connection requirements. Computer generated fan curves for each air handling unit shall be submitted with specific design operating point noted. A computer generated psychometric chart shall be submitted for each cooling coil with design points and final operating point clearly noted. Sound data for discharge, radiated and return positions shall be submitted by octave band for each unit. Calculations for required baserail heights to satisfy condensate trapping requirements of cooling coil shall be included.

B. Product Data:

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DEDICATED OUTSIDE AIR SYSTEM 237433-2

1. Provide literature that indicates dimensions, weights, capacities, ratings, fan performance, finishes of materials, electrical characteristics, and connection requirements.

2. Provide data of filter media, filter performance data, filter assembly, and filter frames.

3. Provide manufacturer's installation instructions.

1.04 QUALIFICATIONS

A. Manufacturer: Company specializing in manufacturing Air Handler products specified in this section must show a minimum five years documented experience and complete catalog data on total product.

1.05 SAFETY AGENCY LISTED & CERTIFICATION

A. Air Handling units shall be cETLus safety listed to conform with UL Standard 1995 and

CAN/CSA Standard C22.2 No. 236. Units shall be accepted for use in New York City by the Department of Building, MEA 342-99-E.

B. Air handler furnished with double width, double inlet (DWDI) fans and/or plenum fans where applicable, shall be certified in accordance with the central station air handling units certification program, which is based on AHRI Standard 430. (NOTE: Above does not apply to fan array)

C. Air handling unit water heating & cooling coils shall be certified in accordance with the forced circulation air cooling and air heating coils certification program, which is based on

AHRI Standard 410.

1.06 DELIVERY, STORAGE, AND HANDLING

A. Deliver, store, protect and handle products to site.

B. Accept products on site on factory-furnished shipping skids. Inspect for damage.

C. Store in clean dry place and protect from construction traffic. Handle carefully to avoid damage to components, enclosures, and finish.

PART 2: PRODUCTS

2.01 ACCEPTABLE MANUFACTURERS

A. The following manufacturers are approved for use. No substitutions will be permitted.

1. Daikin Applied 'Vision' Air Handler shall be the basis of design.

2. Miller-Picking

3. Temtrol

4. Scott-Springfield

5. Racan-Carrier Company

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2.02 GENERAL DESCRIPTION

A. Configuration: Fabricate as detailed on drawings.

B. Performance: Conform to AHRI 430. See schedules on prints. (NOTE: above does not apply to fan array)

C. Acoustics: Sound power levels (dB) for the unit shall not exceed the specified levels shown on the unit schedule. The manufacturer shall provide the necessary sound treatment to meet these levels if required.

2.03 UNIT CONSTRUCTION

A. Fabricate unit with heavy gauge channel posts and panels secured with mechanical fasteners. All panels, access doors, and ship sections shall be sealed with permanently applied bulb-type gasket. Shipped loose gasketing is not allowed.

B. Panels and access doors shall be constructed as a 2-inch nominal thick; thermal broke double wall assembly, injected with foam insulation with an R-value of not less than R-13.

1. The inner liner shall be constructed of G90 galvanized steel.

2. The outer panel shall be constructed of G90 galvanized steel.

3. The floor plate shall be constructed as specified for the inner liner.

4. Unit will be furnished with solid inner liners.

C. Panel deflection shall not exceed L/240 ratio at 125% of design static pressure, maximum

5 inches of positive or 6 inches of negative static pressure. Deflection shall be measured at the panel midpoint.

D. The casing leakage rate shall not exceed 0.50 cfm per square foot of casing surface area at design static pressure up to a maximum of +5” w.c. in positive pressure sections and -

6” w.c. in negative pressure sections (.0025 m3/s per square meter of cabinet area at

1.24 kPa static pressure)

E. Module to module field assembly shall be accomplished with an overlapping, full perimeter internal splice joint that is sealed with bulb type gasketing on both mating modules to minimize on-site labor and meet indoor air quality standards.

F. Access doors shall be flush mounted to cabinetry, with minimum of two six inch long stainless steel piano-type hinges, latch and full size handle assembly. Access doors shall swing outward for unit sections under negative pressure. Access doors on positive pressure sections, shall have a secondary latch to relieve pressure and prevent injury upon access.

G. A 6-inch formed G60 galvanized steel base rail shall be provided by the unit manufacturer for structural rigidity and condensate trapping.. The base rail shall be

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constructed with 12-gauge nominal for unit sizes 003 - 035 and 10-gauge nominal for unit sizes 040 - 090. The following calculation shall determine the required height of the baserail to allow for adequate drainage. Use the largest pressure to determine base rail height. [(Negative)(Positive) static pressure (in)] (2) + 4” = required baserail height.

Should the unit baserail not be factory supplied at this height, the contractor is required to supply a concrete housekeeping pad to make up the difference.

H. Construct drain pans from stainless steel with cross break and double sloping pitch to drain connection. Provide drain pans under cooling coil section. Drain connection centerline shall be a minimum of 3’’ above the base rail to aid in proper condensate trapping. Drain connections that protrude from the base rail are not acceptable. There must be a full 2’’ thickness of insulation under drain pan.

2.04 FAN ASSEMBLIES

A. Acceptable fan assembly shall be a double width, double inlet, class II, belt-drive type housed forward curved fan dynamically balanced as an assembly, as shown in schedule.

Maximum fan RPM shall be below first critical fan speed. Fan assemblies shall be dynamically balanced by the manufacturer on all three planes and at all bearing supports.

Copper lubrication lines shall be provided and extend from the bearings and attached with grease fittings to the fan base assembly near access door. If not supplied at the factory, contractor shall mount copper lube lines in the field. Fan and motor shall be mounted internally on a steel base. Provide access to motor, drive, and bearings through hinged access door.

B. Fan and motor shall be mounted internally on a steel base. Factory mount motor on slide base that can be slid out the side of the unit if removal is required. Provide access to motor, drive, and bearings through hinged access door. Fan and motor assembly shall be mounted on rubber-in-shear vibration type isolators inside cabinetry.

2.05 BEARINGS, SHAFTS, AND DRIVES

A. Bearings: Basic load rating computed in accordance with AFBMA - ANSI Standards.

The bearings shall be designed for service with an L-50 life of 200,000 hours and shall be a heavy duty pillow block, self-aligning, grease-lubricated ball or spherical roller bearing type.

B. Shafts shall be solid, hot rolled steel, ground and polished, keyed to shaft, and protectively coated with lubricating oil. Hollow shafts are not acceptable.

C. V-Belt drives shall be cast iron or steel sheaves, dynamically balanced, bored to fit shafts and keyed. Fixed sheaves, matched belts, and drive rated based on motor horsepower.

Minimum of 2 belts shall be provided on all fans with 10 HP motors and above. Standard drive service factor minimum shall be 1.1 S.F. for 1/4 HP – 7.5 HP, 1.3 S.F. for 10 HP and larger, calculated based on fan brake horsepower.

DEDICATED OUTSIDE AIR SYSTEM 237433-5

2.06 ELECTRICAL

A. Fan motors shall be manufacturer provided and installed, Open Drip Proof, premium efficiency (meets or exceeds EPAct requirements), 1750 RPM, single speed, 200V /

60HZ / 3P. Complete electrical characteristics for each fan motor shall be as shown in schedule.

B. The air handler(s) shall be ETL and ETL-Canada listed by Intertek Testing Services, Inc.

Units shall conform to bi-national standard ANSI/UL Standard 1995/CSA Standard C22.2

No. 236.

C. Wiring Termination: Provide terminal lugs to match branch circuit conductor quantities, sizes, and materials indicated. Enclosed terminal lugs in terminal box sized to NFPA 70.

D. Manufacturer shall provide ASHRAE 90.1 Energy Efficiency equation details for individual equipment to assist Building Engineer for calculating system compliance.

E. Installing contractor shall provide GFI receptacle within 25 feet of unit to satisfy National

Electrical Code requirements.

F. All electrical connection components shall be field provided and mounted as shown on project schedule.

2.07 COOLING AND HEATING COILS

A. Certification: Acceptable water cooling, water heating, steam, and refrigerant coils shall be certified in accordance with AHRI Standard 410 and bear the AHRI label. Coils exceeding the scope of the manufacturer’s certification and/or the range of AHRI’s standard rating conditions will be considered provided the manufacturer is a current member of the AHRI Forced Circulation Air-Cooling and Air-Heating Coils certification programs and that the coils have been rated in accordance with AHRI Standard 410.

Manufacturer must be ISO 9002 certified.

B. Water heating coil shall be provided. Provide access to coil(s) for service and cleaning.

Enclose coil headers and return bends fully within unit casing. Unit shall be provided with coil connections that extend a minimum of 5” beyond unit casing for ease of installation.

Drain and vent connections shall be provided exterior to unit casing. Coil connections must be factory sealed with grommets on interior and exterior panel liners to minimize air leakage and condensation inside panel assembly. If not factory packaged, Contractor must supply all coil connection grommets and sleeves. Coils shall be removable through side and/or top panels of unit without the need to remove and disassemble the entire section from the unit.

1. Headers shall consist of seamless copper tubing to assure compatibility with primary surface. Headers to have intruded tube holes to provide maximum brazing surface for tube

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DEDICATED OUTSIDE AIR SYSTEM 237433-6

to header joint, strength, and inherent flexibility. Header diameter should vary with fluid flow requirements.

2. Fins shall have a minimum thickness of 0.0075 inch aluminum plate construction. Fins shall have full drawn collars to provide a continuous surface cover over the entire tube for maximum heat transfer. Tubes shall be mechanically expanded into the fins to provide a continuous primary to secondary compression bond over the entire finned length for maximum heat transfer rates. Bare copper tubes shall not be visible between fins.

3. Coil tubes shall be 5/8 inch OD seamless copper, 0.020 inch nominal tube wall thickness, expanded into fins, brazed at joints.

4. Coil connections shall be carbon steel, threaded connection. Connection size to be determined by manufacturer based upon the most efficient coil circuiting. Vent and drain fittings shall be furnished on the connections, exterior to the air handler. Vent connections provided at the highest point to assure proper venting. Drain connections shall be provided at the lowest point to insure complete drainage and prevent freeze-up.

5. Coil shall be furnished as an uncased galvanized steel to allow for thermal movement and slide into a pitched track for fluid drainage.

C. Direct expansion refrigerant cooling coil shall be provided. Provide access to coil(s) for service and cleaning. Enclose coil headers and return bends fully within unit casing. Unit shall be provided with coil connections that extend a minimum of 3” beyond unit casing for ease of installation. Coil connections must be factory sealed with grommets on interior and exterior panel liners to minimize air leakage and condensation inside panel assembly.

If not factory packaged, Contractor must supply all coil connection grommets and sleeves.

Coils shall be removable through side and/or top panels of unit without the need to remove and disassemble the entire section from the unit.

1. Sweat type copper suction headers shall be provided.

2. Fins shall have a minimum thickness of 0.0075 inch aluminum plate construction. Fins shall have full drawn collars to provide a continuous surface cover over the entire tube for maximum heat transfer. Tubes shall be mechanically expanded into the fins to provide a continuous primary to secondary compression bond over the entire finned length for maximum heat transfer rates. Bare copper tubes shall not be visible between fins.

3. Coil tubes shall be 5/8 inch OD seamless copper, 0.020 inch nominal tube wall thickness, expanded into fins on 1 1/2-inch centers, brazed at joints.

4. Sweat type copper suction connections located at the bottom of the suction headers for gravity oil drainage. Coils shall be uniformly circuited in a counterflow manner for either single circuit, row, face, interlaced, or interlaced face split capacity reduction as shown on unit schedule. Pressure type liquid distributors used. Coils shall be tested with 315 pounds air pressure under warm water, and suitable for 250 psig working pressure.

5. Coil casing shall be a formed channel frame of galvanized steel.

2.08 FILTERS

A. Furnish flat panel filter section with 2-inch pleated MERV 8 filter. Provide side loading and removal of filters.

B. Filter media shall be UL 900 listed, Class I or Class II.

DEDICATED OUTSIDE AIR SYSTEM 237433-7

C. Filter Magnehelic gauge(s) shall be furnished and mounted by others.

2.09 ADDITIONAL SECTIONS

A. Factory installed wrap-around dehumidifier heat pipes shall precool the return/outside air and reheat the supply air in a wrap-around configuration. The precool heat pipe module shall be located immediately before the cooling coil and the reheat module of the heat pipe shall be located immediately after the cooling coil. Heat pipe circuits comprise multiple tubes connected in series, end-to-end to form a closed, continuous loop. Both vapor and liquid will travel in the same direction around the circuit in a single convectional path, making wicking and capillary action unnecessary for continuous heat transfer. Both heat pipe modules shall be inside the equipment cabinet. The interconnecting piping between the heat pipe modules shall be located within the assembled access/coil/access sections. If not, the piping shall be external, but enclosed within a removable, insulated enclosure supplied and installed by others. When possible, all interconnecting piping shall be located at the end of the cooling coil opposite from the coil header and piping connections. Heat pipes shall be completely manufactured and fully assembled at the manufacturer’s facility or on site by factory personnel.

B. The precool heat pipe module shall be located immediately upstream of the cooling coil section and the reheat heat pipe module shall be located immediately downstream of the cooling coil section with drain pans, or a single extended drain pan, positioned beneath.

For optimal accessibility between the cooling coil and the heat pipe modules, the air handler cooling coil section(s) shall be supplied with two (2) factory installed blank sections located immediately before and after the cooling coil section. Each section shall be provided with an integral condensate drain panand drain pan condensate connection of the same construction as specified for the cooling coil. The precool heat pipe module shall be located within the provided blank section before the cooling coil section, and the reheat heat pipe module shall be located within the provided blank section after the cooling coil section.

C. All of the dehumidifier heat pipe circuits shall be equipped with solenoid operated control valves to control the operation of the heat pipe circuits. The electrical power required by the solenoid valves shall be 24 VAC. The solenoid valves shall be wired to a terminal block within a NEMA enclosure. The Building Automation system shall provide the sensors necessary for determination of heat pipe staged operation and the BAS shall be programmed to send the operating control signals to the solenoid valves as required for correct system operation. All additional wiring, relays, transformers, power supply, etc.

necessary to interface with the equipment control system, shall be provided and installed by others. Closing of a valve shall inactivate the heat pipe circuit in which it is installed.

The valves shall be normally open. The control valves shall be grouped such that each group of valves shall control a designated fraction of the heat pipe circuits. With all control valves open, the dehumidifier heat pipe assembly will operate at full capacity. I all the circuits are equipped with control valves, then closing all the valves will stop all heat pipe operation.

D. The tubes shall be 1/2" OD copper, of specific design for heat pipe application, permanently expanded onto the fin collar to form a firm, rigid, and complete pressure contact at all operating conditions. Aluminum tubes will not be allowed. Tubes shall be no larger than 5/8” OD. The fin surface shall be continuous plate type aluminum fins of specific design to produce maximum heat transfer efficiency for heat pipe applications.

Airside pressure loss shall be as given on the schedule, or otherwise specified. Fin

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density and the number of rows of tubes shall be as specified. Heat transfer fluid shall be classified as Safety Group A1 in ASHRAE Standard 34-2013.

E. Heat pipe capacities, entering and leaving dry and wet bulb temperatures, and face velocity shall be as scheduled. Frames, mounting structure, and drain pan extensions (if required) shall be minimum 16 gauge stainless steel.

F. Heat pipe coils and interconnecting piping and circuitry shall be as specified by Heat Pipe

Technology, Inc. Each circuit shall be individually processed, charged, hermetically sealed, and tested. Scheduled effectiveness or heat recovery shall be met at a minimum and total pressure drop shall not be exceeded. The resulting Recovery Efficiency Ratio, or RER, shall therefore be met at a minimum. The heat pipe heat exchanger shall have a five (5) year limited warranty. All components such as valves and dampers shall carry a 12 month warranty.

2.10 ENVIRONMENTAL REQUIREMENTS

A. Do not operate units for any purpose, temporary or permanent, until ductwork is clean;

filters are in place; bearings lubricated; building is enclosed, sealed, and cleaned; and fan has been test run under observation.

2.11 HEAT PUMP CONDENSING UNIT

A. General:

1. The outdoor unit shall be factory assembled and pre-wired with all necessary electronic and refrigerant controls. The refrigeration circuit of the condensing unit shall consist of a swing compressor, motors, fan, condenser coil, electronic expansion valves, solenoid valves, 4 way valve, distribution headers, capillaries, filters, shut off valves, service ports and suction accumulator.

2. Both liquid and suction lines must be individually insulated between the outdoor and indoor units.

3. The outdoor unit can be wired and piped with outdoor unit access from the left, right, front or rear.

4. The system will automatically restart operation after a power failure and will not cause any settings to be lost, thus eliminating the need for re-programming.

5. The outdoor unit shall be modular in design and should allow for side-by- side installation with minimum spacing.

6. The following safety devices shall be included on the condensing unit; high pressure switch, control circuit fuses, fusible plug, high pressure switch, overload relay, inverter overload protector, thermal protectors for compressor and fan motors, over current protection for the inverter and anti-recycling timers.

7. Oil recovery cycle shall be automatic occurring 2 hours after start of operation and then every 8 hours of operation.

8. The outdoor unit shall be capable of cooling operation at 0°F dry bulb ambient temperature without additional low ambient controls.

B. Unit Cabinet:

1. The outdoor unit shall be completely weatherproof and corrosion resistant.

The unit shall be constructed from rust-proofed mild steel panels coated with a baked enamel finish.

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C. Fan:

1. The condensing unit shall consist of one propeller type, direct-drive fan motor that has multiple speed operation via a DC (digitally commutating) inverter.

2. The fan shall be a vertical discharge configuration.

3. The fan motor shall have inherent protection and permanently lubricated bearings and be mounted.

4. The fan motor shall be provided with a fan guard to prevent contact with moving parts.

5. The outdoor unit shall be capable of operating at further reduced sound levels during night time.

D. Condenser Coil:

1. The condenser coil shall be manufactured from copper tubes expanded into aluminum fins to form a mechanical bond.

2. The heat exchanger coil shall be of a waffle louver fin and rifled bore tube design to ensure highly efficient performance.

3. The heat exchanger on the condensing units shall be manufactured from seamless copper tube with internal grooves mechanically bonded on to aluminum fins.

E. Compressor:

1. The compressor shall be variable speed inverter controlled which is capable of changing the speed to follow the variations in total cooling load as determined by the suction gas pressure as measured in the condensing unit. In addition, samplings of evaporator and condenser temperatures shall be made so that the high/low pressures detected are read every 20 seconds and calculated. With each reading, the compressor capacity shall be controlled to eliminate deviation from target value.

2. The inverter driven compressor shall be of highly efficient reluctance DC (digitally commutating), hermetically sealed swing “F-type” type.

3. Neodymium magnets shall be adopted in the rotor construction to yield a higher torque and efficiency in the compressor instead of the normal ferrite magnet type. At complete stop of the compressor, the neodymium magnets will position the rotor into the optimum position for a low torque start.

4. The capacity control range shall be 35-100%.

5. The compressor shall be equipped with a crankcase heater, high pressure safety switch and internal thermal overload protector.

6. The compressor shall be mounted to avoid the transmission of vibration.

F. Electrical:

1. The power supply to the outdoor unit shall be 208-230 volts, 1 phase, 60 hertz +/- 10%.

2. The control voltage between the indoor and outdoor unit shall be 16VDC non-shielded, stranded 2 conductor cable.

3. The control wiring shall be a two-wire multiplex transmission system, thus simplifying the wiring operation.

PART 3: EXECUTION

3.01 INSTALLATION

A. Install in accordance with manufacturer’s Installation & Maintenance instructions.

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3.02 ENVIRONMENTAL REQUIREMENTS

A. Do not operate units for any purpose, temporary or permanent, until ductwork is clean, filters are in place, bearings lubricated, and fan has been test run under observation.

3.03 EXTRA MATERIALS

A. Provide [one, two, etc.] extra set(s) [fan belts, filters, etc.] for each unit as shown on project schedule.

END OF SECTION 237433