ENERGY LABS, INC._



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|SECTION __________ |

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|CUSTOM PACKAGED DX AIR HANDLING UNIT SPECIFICATION |

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PART 1 GENERAL

1.1 DESCRIPTION OF WORK

A. Custom Packaged DX air handling units.

B. Economizer sections where noted on drawings.

C. Supply fan section.

D. Return fan section where noted on drawings.

E. Internal vibration isolation.

F. Filter section.

G. Cooling coils.

H. Heating coils.

I. Accessories.

J. Mechanical variable volume devices.

1.2 REFERENCES

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

B. AFBMA 11 - Load Ratings and Fatigue Life for Roller Bearings.

C. AMCA 99 - Standards Handbook.

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

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

F. AMCA 301 - Method of Publishing Sound Ratings for Air Moving Devices.

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

H. ARI 410 - Forced-Circulation Air-Cooling and Air-Heating Coils.

I. ARI 430 - Central Station Air Handling Units.

J. ARI 435 - Application of Central Station Air Handling Units.

K. ARI 610 - Central System Humidifiers.

L. NEMA MG1 - Motors and Generators.

M. NFPA 70 - National Electrical Code.

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

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

1.3 SUBMITTALS

A. Submit under provisions of General Conditions and Division 1 as applicable.

B. Shop Drawings: Indicate assembly, unit dimensions, weight loading, required clearances, construction details, field connection details and electrical characteristics and connection requirements.

C. Product Data:

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

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

3. Provide fan curves with specified operating point clearly plotted.

4. Submit sound power level data for both fan outlet, fan inlet and casing radiation at rated capacity.

5. Submit electrical requirements for power supply wiring including wiring diagrams for interlock and control wiring, clearly indicating factory installed and field installed wiring.

6. Submit performance, noise and vibration test results of the laboratory air handling unit and office air handling unit. Provide test results for review prior to any air handling unit shipment to the jobsite.

1.4 OPERATION AND MAINTENANCE DATA

A. Submit under provisions of General Conditions and Division 1 as applicable.

B. Maintenance Data: Include instructions for lubrication, filter replacement, motor and drive replacement, spare parts lists and wiring diagrams.

C. Manufacturer’s Installation Instructions.

1.5 QUALIFICATIONS

A. Manufacturer: Company specializing in manufacturing the products specified in this section with minimum ten (10) years documented experience, who issues complete catalog data on total product.

1.6 DELIVERY, STORAGE, AND HANDLING

A. Deliver, store, protect and handle products to site under provisions of General Conditions and Division 1 as applicable.

B. Accept products on site in factory fabricated protective containers with factory installed shipping skids and lifting lugs. Inspect for damage.

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

1.7 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.

1.8 EXTRA MATERIALS

A. Furnish under provisions of General Conditions and Division 1 as applicable.

1.9 QUALITY ASSURANCE

A. Conform to space and access requirements; units will not be accepted which do not conform to space and access requirements.

PART 2 PRODUCTS

2.1 MANUFACTURERS

A. Energy Labs.

B. Governair Corporation

C. Webco, Inc

Manufacturers listed by name does not imply that their standard method of unit manufacture is acceptable or approved. All manufacturers shall meet or exceed all requirements of this specification without exception.

2.2 CUSTOM PACKAGED DX AIR HANDLING UNITS

A. Units shall be factory built, double wall construction with components listed in attached schedule.

B. Arrangement: Refer to the plan drawing.

C. Unit Construction: The following sections describe in detail construction requirements for the unit base, cabinet, access doors, insulation and paint finish. Unit shall be built for outdoor installation.

1. Unit Base: Each unit shall be constructed on a base fabricated from heavy duty welded structural steel channel. Formed metal tubular bases or formed metal channel bases are not acceptable. Channel bases shall be sized as a function of air handling length as follows:

|A.H. UNIT |MINIMUM | |

|LENGTH |CHANNEL SIZE | |

|UP to 15’.............................. |4” x 1-5/8” |(5.4#/Lin.Ft.) |

|10’ - 20’ ...............................|6” x 2” |(8.2#/Lin.Ft.) |

|15’ to 25’.............................. |8” x 2-1/2” |(11.5#/Lin.Ft.) |

|20’ x 30’............................... |10” x 2-5/8” |(15.3#/Lin.Ft.) |

|25’ x 40’............................... |12” x 3” |(20.7#/Lin.Ft.) |

a. Heavy welded lifting lugs shall be added to the perimeter channel along the longest length of the unit section.

b. The unit floor shall be fabricated of 16 gauge hot rolled galvanized steel sheets. Each sheet of flooring material shall have a base structural member centered under all edges for adequate support. All floor seams shall be fully welded flush to maintain an air tight seal. The flooring shall be welded to the structural members below. Welds from below the floor shall be spaced no greater than 4” on center. Drive screw attachment is not acceptable.

2. Unit Housing

a. The unit housing side and roof panels shall be constructed of 16-gauge galvanized steel, and shall utilize a standing seam modular panel type construction. The panels shall be attached to each other, to the roof, and to the floor using bolts. Drive screw attachment is not acceptable. All seams shall be sealed with an acrylic latex sealant prior to assembling the panels and after completion of the assembly.

b. All floor openings shall have 1” minimum flange up around the entire perimeter.

c. (Type F) Doors shall be double wall, insulated, man size, double seal type with two separate gaskets closing to knife-edges. Doorframe shall be powder coated extruded aluminum with stainless steel powder coated adjustable hinges. Door handles and hinges shall be fully adjustable. Door handles shall incorporate a roller cam to insure airtight fit. Doors shall be operable from inside as well as outside unit. Ventlock type handles are not acceptable.

d. Door hinges and latches shall be easily adjustable, without the use of shims or special tools, to allow for a tight seal between the door and the unit as the gasketing material compresses over time.

e. Latches shall utilize non-corrosive door handles on exterior and roller cam type on interior.

f. (Option) Include a 9” x 9” wire dual glazed reinforced glass view window in each fan access door.

3. Insulation: Wall and Ceiling Insulation shall be 2” (Option 4”) thick, 1½# (Option 3#) per cubic foot density, neoprene coated fiberglass and cover all walls, ceilings and under floors. Insulation shall meet NFPA-90A smoke and flame spread requirements. There shall be no insulation exposed to the air stream. All other sections shall have 20 gauge solid steel liners. Each panel shall be individually removable and be used to secure the insulation in place. (Option) All fan sections shall have a 20-gauge perforated steel acoustical sheet metal liner covering all walls and ceiling surfaces.

4. Floor insulation shall be 2” minimal polyurethane continuous foam-in-place insulation applied to underside of floor liners. Fiberglass insulation in bases is not acceptable as they do not prevent oil-canning and have inherent gaps between batts which compromise the r-factor of the insulation.

5. Paint Finish: After final assembly the unit exterior shall be coated with an industrial grade polyurethane paint. In addition, all fan bases, springs and structural steel supports shall be coated with the same finish. The paint system shall meet ASTM B Salt fog test for a minimum 2000 hours.

F. Internal Components

1. Fan Assembly (Arrangement #1 Plenum Fan or Direct Drive)

a. All fan assemblies supplied for the air handlers shall be manufactured by the air handling unit manufacturer for the purpose of sole source responsibility.

b. Fan performance shall be based on tests run in an AMCA certified laboratory and administered in accordance with AMCA Standard 210. Fan performance tests shall be taken with fans running inside the cabinet to include any affects from the unit cabinet and other internal components.

c. Fans shall be configured so that both fan bearings are on the same side of the wheel with the wheel over hung (Arrangement #1) or direct drive as shown on plans. There shall be no obstructions (i.e., bearings or bearing supports, etc.,) at the inlet of the fan. All Plenum fan wheels shall be aluminum construction.

d. Each fan shall be sized to perform as indicated on the equipment schedule. The wheel diameter shall not be less than that shown on the equipment schedule. The fan shall be constructed to AMCA Standards for the Class Rating as indicated on the Equipment Schedule.

e. For belt driven fans, provide pressure relief type grease fittings and extend lubrication lines to the motor side of the fan just inside its access door.

2. Fan Base, Spring Isolation, and Support Framing

a. Mount fan and motor on an internal, fully welded, rigid structural steel channel base. Base shall be free-floating at all four corners on spring type isolators with earthquake restraints. The fan assembly shall be isolated from the cabinet by steel springs with deflection as indicated in schedules.

b. The fan discharge shall be isolated from the cabinet by means of a neoprene-coated flexible connection. If belt driven, L10- 200,000 Hr. operating life bearings shall be mounted on a structural steel channel or machined surface. The structure supporting the bearing bar shall be fabricated from structural steel and detachable to allow for removal of the fan wheel and shaft as one piece.

3. Balancing

a. The shafting of the fan shall be sized not to exceed 75% of the first critical speed for maximum RPM of Class specified. The critical speed will refer to the top of the speed range of the fans’ AMCA class. The lateral static deflection shall not exceed 0.003” per foot of the length of the shaft.

VIBRATION - [BELT DRIVE] Fan wheels and shaft assemblies shall be factory dynamically balanced and shall meet or exceed guidelines in AMCA 204-96 for Balance Quality and Vibration Levels for Fan Application Category BV-3.  Following fan assembly, the complete spring isolated fan assembly shall be tested using an electronic balance analyzer with tunable filter and stroboscope.  Vibration measurements shall be taken on each fan bearing housing in the vertical, horizontal, and axial planes (6 total measurements, 3 each fan bearing).  The maximum allowable peak velocity shall not exceed 0.125 inches per second peak amplitude (filter in) on any of 6 readings and sum of all readings shall not exceed 1.5 mils displacement when fan is running at 1135 rpm.  A copy of the Vibration test report (Vibration Nomograph) shall be provided with the Operation and Maintenance Manual upon request.  The fan assembly shall also be vibration tested at design RPM with the spring isolators at the specified deflection, with the tunable filter utilized and frequencies from 500 cpm to 50,000 cpm shall be scanned to detect misalignment, bearing defects, mechanical looseness or foundation weakness.

VIBRATION - [DIRECT DRIVE] Fan wheel shall be factory dynamically balanced and shall meet or exceed guidelines in AMCA 204-96 for Balance Quality and Vibration Levels for Fan Application Category BV-3.  Following fan assembly, the complete spring isolated fan assembly shall be tested using an electronic balance analyzer with tunable filter and stroboscope.  Vibration measurements shall be taken on each motor bearing housing in the vertical, horizontal, and axial planes (5 total measurements, 2 each motor bearing and 1 Axial).  The maximum allowable velocity shall not exceed 0.125 inches per second peak amplitude (filter in) on any of 5 readings and the sum of all readings shall not exceed .5 mils @ 1170 rpm.  A copy of the Vibration test report (Vibration Nomograph) shall be provided with the Operation and Maintenance Manual upon request.  The fan assembly shall also be vibration tested at design RPM with the spring isolators at the specified deflection, with the tunable filter utilized and frequencies from 500 cpm to 50,000 cpm shall be scanned to detect misalignment, bearing defects, mechanical looseness or foundation weakness.

 

b. A copy of the above balance test data for this project showing calculations for deflection and critical speed of the shaft and wheel assembly shall be submitted to the engineer and a copy forwarded to the Owner.

4. Motors and Drive

a. Furnish high-efficiency open drip proof standard NEMA frame rigid ball bearing type motors. Reliance “Alpha”, Century “E-Plus”, or Marathon “ZRI” with grease lubricated bearings and alemite fittings. Horsepower as shown on the schedule are minimum allowable.

b. The motor shall be mounted on an adjustable slide rail motor base. The fan motors shall be factory wired to an external junction box with flexible conduit of adequate length so that it will not have any affect on the vibration isolation.

c. If belt driven, provide V-belt type, cast-iron sheaves, and reinforced rubber belts. The belts shall be selected for 150% of the motor nameplate horsepower. Drives shall be “Browning” or equal by “Woods.”

5. Coils

a. Cooling coils shall be the plate fin extended surface type. The primary surface shall be a minimum of 5/8” outside diameter seamless copper with a 0.020” minimum wall thickness. Each coil shall have individually replaceable return bends of 0.025 wall thickness minimum on both sides of the coil. Coils incorporating a “hairpin” type design are not acceptable. Tubes shall be expanded into the fin collars to provide a permanent mechanical bond.

b. The secondary surface shall be flat or formed of 0.008” aluminum fins and shall be spaced not closer than 12 fins per inch with integral spacing collars that cover the tube surface. Headers shall be non-ferrous seamless copper. Chilled water coil coils shall be tobin bronze brazed steel male pipe connections and 1/8” pipe vent and drain connection extended to outside of unit casing.

c. Direct Expansion Coils shall have copper sweat suction connections and refrigerant distributor liquid connections, and shall be provided with adjustable superheat controls and external equalizer lines.

d. Cooling coil casing shall be minimum 16-gauge, 304 stainless steel with double formed 1/2” stacking flanges and 3/4” flanges on the side plates. Flanged tube sheets shall have extruded tube holes. Reinforcing rods shall be furnished so that the unsupported length is not over 60”. All coil assemblies shall be tested under water at 300 psi and rated for 150-psi working pressure. Provide diverter plates at both ends of the coil to divert the condensate drip from the headers and return bends into the drain pan. Headers are to be located inside the cabinet casing with only the pipe connections extending through the casing.

e. Coils shall be fully blanked to ensure all air passes through the coil. Intermediate condensate pans are to be furnished on multiple coil units with copper down tubes to the main drain panel.

f. 304 Stainless steel IAQ double sloped recessed drain pans shall be provided as an integral part of the unit base in all cooling coil sections. Pans shall be 16-gauge minimum with 1”-1½ lb. density, neoprene coated fiberglass insulation and a 16-gauge under liner. Stainless steel condensate connections shall be provided on one side of the unit.

g. All chilled water coils shall be certified in accordance with ARI Standard 410.

6. Filters

a. Filter sections shall be fabricated as part of the air handling unit. Filters shall be arranged for upstream, downstream, or side loading as shown on the drawings. Provide filter holding frames to accommodate scheduled filters.

b. Factory install at each filter bank a Dwyer Magnehelic “Series 2000” pressure gauge complete with static pressure tips, hardware and fittings. Enclose the gauges in a protective sheet metal box with a hinged inspection door. Paint to match unit. Provide separate filter gage for each pre and each final filter bank.

7. Economizer

a. Economizer section shall include dampers for return air, fresh air and exhaust air. Dampers shall be opposed blade type. Dampers shall be sized for approximately 1200 fpm face velocity based upon gross damper area. Furnish full height 24” wide access doors for damper and linkage service.

b. Dampers shall be extruded aluminum type with rubber edge seals and stainless steel arc end seals. Dampers shall be low leak and incorporate nylon bearings.

c. Provide louvers for outside air and exhaust for units located outdoors. Louvers shall be sized for a maximum face velocity of 450 fpm based on gross louver area. Hoods in lieu of louvers are not acceptable.

8. (Option) Marine Service Lights: Vapor proof marine lights shall be factory wired to individual switches located next to access doors for fan sections, filter sections, and economizer sections.

G. (Option) Air Flow Measuring Stations – Fans and OSA

1. Fans shall be supplied with a complete flow measuring system capable of supplying a 4 - 20 mA output signal to the EMS system that is proportional to air flow. The flow measuring station and a flow transmitter, both factory mounted and piped.

2. The flow measuring station shall consist of total and static pressure pick-ups located in the inlet cone(s) of each fan. OSA measurement device shall be located at the OSA (minimum) damper. OSA measurement device shall be based on thermal dispersion and be 2% to 5% accurate from 0 to 10000 FPM velocity. OSA measurement station shall be NIST traceable. OSA measurement station shall be Ebtron “Gold” series or prior approved equal. (No know equal)

3. Provide a Magnehelic gauge with CFM scale on external side of the fan sections which indicates the fan volume.

4. The electronic flow transmitter shall be capable of receiving signals of total and static pressure from a flow element, of amplifying, extracting the square root, and scaling to produce a 4 - 20 mADC output signal linear and scaled to air volume or velocity. The flow transmitter shall be capable of the following performance and application criteria.

a.) Calibrated spans from 0 - 896 FPM, in eight flow range increments. Output signal 4 - 20 mADC standard. Integral zeroing means 3-way zeroing valve with manual switch. Temperature effect ± 2.0% of full span from 40° to 120°F

5. The transmitter shall not be damaged by over-pressurization up to 200 times greater than span, and shall be furnished with a factory calibrated span and integral zeroing means. The transmitter shall be housed in a NEMA 12 enclosure with external signal tubing, power, and output signal connections.

6. The electronic differential pressure transmitter shall be Dwyer model 605, Setra 264 or equal. OSA transmitter shall be Ebtron GTA116

H. DX Condensing Sections

1. The DX Condensing Section shall be fully integrated with the air handling section and shall be self manufactured by the air handling unit manufacturer in the same facility as the air handling section. Third party purchased condensing units skid mounted to the air handling section are not acceptable due to the lack of single source responsibility and quality control by the air handling unit manufacturer.

2. Compressors shall be of the hermetic scroll or semi-hermetic screw type. Reciprocating compressors are not acceptable due to their inherently excessive noise and vibration characteristics. Each refrigeration circuit shall include all specialties for proper operation, including liquid line filter drier and sightglass, refrigerant distributor(s) with thermal expansion valve(s), and charging/service ports.

a. Scroll Compressors

Compressor shall be of compliant design for axial and radial sealing of the scrolls. Motor shall be suction gas cooled, with sufficient suction side free volume and oil sump to provide

liquid handling capability. Compressor to include annular discharge check valve to provide low pressure drop, silent shutdown, and reverse rotation protection. (Option) compressors to include belly band heaters for additional liquid migration protection. Compressors may be arranged in tandem, triple and quad configuration on a single refrigeration circuit.

b. Screw Compressors

Compressors shall be of the single stage, positive displacement, 3550 RPM hermetic motor driven, rotary screw type, including an integral oil separation system, oil sump, oil filter, and integral solid state motor protection. Each screw compressor capacity control shall be achieved by infinitely variable slide valve unloading.

3. Condensing unit

a. Air Cooled Condensing Units

Air Cooled Condensing Units shall incorporate a V style coil arrangement to minimize the footprint and height of the unit. The entire condenser section shall be supported

Condenser coils shall be constructed of seamless copper tubing mechanically expanded into aluminum (option copper) fins, and incorporate an integral subcooling circuit. Fin spacing to be no greater than 12 fpi.

Condenser Fans shall be direct drive propeller type with venturis for efficient performance and low sound levels, and shall incorporate an external fan guard for each fan to protect against inadvertent contact with the moving fans. Head pressure control is maintained by fan cycling (option – variable speed motor control.)

b. Evaporative Cooled Condensing Units

Evaporative Cooled Condensing Units shall be of the draw through type. Blow through designs are not acceptable due to higher fan power requirements and the likelihood of outward water leakage due to positive pressures inside the wet section. The condenser sump shall be constructed of stainless steel, and shall be double sloped to drain to facilitate cleaning and maintenance.

All make up water, recirculation water, and drain piping shall be factory piped by the unit manufacturer. Water circulation system shall incorporate a minimum of two pumps for redundancy. Single pump designs shall not be acceptable due to the lack of redundancy of a critical component. Spray nozzles shall be of the spiral type to prevent clogging. Moisture eliminators shall be provided on the air inlet and above the spray tree to prevent moisture carryover.

Evaporative Condenser Coils shall be constructed of seamless copper tubing supported by non-metallic tube sheets supported in stainless steel frames, to permit expansion and prevent contact between dissimilar metals and galvanic corrosion. Designs that incorporate finned “desuperheater” coils are not acceptable due to the inherent scaling and corrosion involved with the wet environment inside the condenser. If a desuperheater circuit is included, the manufacturer shall provide a lifetime warranty against failure due to scaling and/or corrosion.

Condenser Fans shall be direct drive propeller type with venturis for efficient performance and low sound levels, and shall incorporate an external fan guard for each fan to protect against inadvertent contact with the moving fans. Head pressure control is maintained by fan cycling (option – variable speed motor control.)

c. Water Cooled Condensing Units

Water Cooled Condensing Units shall incorporate ASME certified cleanable shell & tube type condensers with removable heads. Condenser water connections shall be grooved end pipe coupling type (Victaulic) to facilitate head removal and tube cleaning with minimal disruption to the piping system.

I. Gas Heat

a. Heat Exchanger

The heat exchanger primary drum shall be constructed of 16-gauge formed and welded series 300 stainless steel. Secondary tubes shall be constructed of 14-gauge high carbon steel {option - series 400 stainless steel}.

b. Power Burner & Gas Train

The burner shall be of the power firing type and incorporate a primary combustion air blower and spark ignition transformer. The gas train shall be complete with all ETL approved controls and shall be factory mounted in the unit heater vestibule. Standard controls include main gas valve, flame supervision, positive burner safety switch, pilot cock, main gas cock, adjustable main, and pilot pressure regulators. The burner shall be factory fired and adjusted for proper combustion. Final adjustment will be made in the field during unit start-up by a factory representative or by a service organization certified by the unit manufacturer. {option -The gas train shall be complete with all components required to meet FM code or IRI code.}

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J. Controls

1. All controls shall be factory mounted by the Air Handling Unit manufacturer and be UL 705 certified. These controls shall include all damper actuators, temperature sensors, pressure sensors, air flow measuring sensors, filter switches, smoke and fire detectors as indicated on the control drawings.

2. Electric and electronic controls shall be wired in UL approved conduit to a terminal block in a sheet metal UL Listed enclosure located at a common location mounted on the air handling unit. All pressure sensing controls shall be piped to a common point on the unit with 1/4” compression fittings.

3. All chilled water and hot water control valves shall be field mounted. In addition, all necessary piping specialties including strainers, shut-off valves, thermometers, pressure taps, air vents, etc. shall be field installed as indicated on the piping diagram. Control valve wiring (electric) or control tubing (pneumatic) shall be extended to a common point on the Air Handling Unit by the air handler manufacturer.

(B) Electrical

1. Unit manufacturer shall supply a single point power panel for main supply voltage. Separate 115-volt power for lights and controls shall be provide by Div 16.

2. Single point power panel shall include all necessary fuses, non-fused main disconnect, fan motor starters or VFD’s as specified in section ______, control transformer and terminals for remote control interconnection

3. Power panel shall be UL508 labeled as a complete assembly. UL label for enclosure only with UL internal components is not acceptable. Enclosure shall be NEMA –4 construction UL listed.

4. All wiring shall be in compliance of the current National Electric Code. All wiring shall be done by a UL705 certified shop at the factory. Field wiring is not acceptable.

K. Sound Power and Performance Certification

1. Air handling unit sound power data shall be submitted for review by Owner’s representative. Sound power data shall be given at the supply connection(s) (outlet) and return connection(s) (inlet) in addition to radiated sound power from the cabinet. Raw fan sound power data shall be derived from tests done in accordance with AMCA Standard 300-85. Data extrapolated from non-like fan sizes and types scheduled is not acceptable. Attenuation assumed for the cabinet configuration, type of insulation, opening locations and sizes, etc., shall be verified through actual test measurements. The mechanical engineer may, at his option, request copies of such tests.

2. (Option) The manufacturer shall perform actual sound test on one selected AHU in accordance with AMCA Standard 300-85. The mechanical engineer shall select the test AHU after review of the submittal.

a. Manufacturer shall perform the sound test in an AMCA lab accredited for both AMCA 210 performance and AMCA 300 sound. Test lab accredited for just one or the other is not acceptable.

b. The mechanical and acoustics engineers shall be allowed to witness the sound test. The AHU manufacturer shall notify the mechanical engineer a minimum of ten (10) days prior to test as to the location and date of the sound test. The travel costs incurred by test witnesses shall be borne by the equipment manufacturer.

c If the sound test indicates the AHU noise levels exceed levels of units specified, the manufacturer shall take corrective measures to reduce the sound. Any modifications that are necessary to meet scheduled sound levels shall be applied to all AHU’s represented by the test unit. Test results shall be submitted to the Owner’s Representative for approval prior to shipment of any equipment.

L. Air Leakage Test (Option)

1. Apparatus

a. A U-Tube manometer shall be used to measure the static pressure exerted on the unit cabinet. The manometer must have graduations no larger than 0.2” (inches of water gauge).

b. A pressure blower that is capable of producing the required pressure without operating at a stall shall be used to perform the test. The pressurizing fan shall be attached to a flow metering station which shall measure the volume flow rate by pressure drop through one or more ASME long radius nozzles. The test apparatus shall have a means of dampering such that the required pressure may be exerted without over-pressurizing the cabinet.

c. Air density shall be determined with wet and dry bulb thermometers and a mercury barometer or equivalent.

2. Procedure

a. The fan unit shall have all duct, damper, and louver openings sealed with plywood or sheet metal and caulked or taped.

b. The static pressure tap shall be arranged with one leg open to atmosphere and one leg tapped to the cabinet interior.

c. A static pressure load of 1.25 times the maximum calculated system total static pressure or 12” whichever is less, will be exerted on the cabinet.

d. The leakage rate will be recorded at the flow measuring apparatus. The air density at which the test was performed will be determined. The test results will be corrected to standard air. An AHU will be considered acceptable if it leaks at a rate of not more than one percent of the design volume.

M. Warranty/Start-Up Service

1. Manufacturer shall provide factory start-up service for each air handling unit. Provide 18 month limited parts and labor warranty from date of unit shipment.

PART 3 EXECUTION

3.1 INSTALLATION

A. Install in accordance with manufacturer’s instructions.

B. Install in conformance with ARI 435.

C. Assemble high pressure units by bolting sections together. Isolate fan section with flexible duct connections.

END OF SECTION

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