237433.pdf

237433 - 1 DEDICATED OUTDOOR-AIR

UNITS

SECTION 237433 - DEDICATED OUTDOOR-AIR UNITS

PART 1 - GENERAL

1.1 RELATED DOCUMENTS

A. Drawings and general provisions of the Contract, including General and Supplementary Conditions and Division 01 Specification Sections, apply to this Section.

1.2 ACTION SUBMITTALS

A. Product Data: For each type of product. Include rated capacities, operating characteristics, and furnished specialties and accessories.

1. Materials of construction, including casing construction details and finishes.

2. Fan curves showing CFM, external and total static pressure, and RPM for operating range of 10% above and below design conditions. Clearly indicate specified operating point

B. Shop Drawings:

1. Include plans, elevations, sections, and attachment details.

2. Include details of equipment assemblies. Indicate dimensions, weights, loads, required clearances, method of field assembly, components, and location and size of each field connection.

3. Prepare the following by or under the supervision of a qualified professional engineer:

a. Include diagrams for power, signal, and control wiring.

1) Clearly indicate factory installed and field installed wiring.

1.3 INFORMATIONAL SUBMITTALS

A. Startup service reports.

1.4 CLOSEOUT SUBMITTALS

A. Operation and Maintenance Data: For units to include in emergency, operation, and maintenance manuals.

1.5 MAINTENANCE MATERIAL SUBMITTALS

A. Furnish extra materials that match products installed and that are packaged with protective covering for storage and identified with labels describing contents.

1. Fan Belts: One set for each belt-driven fan.

2. Filters: One set for each unit.

DEDICATED OUTDOOR-AIR

237433 - 2

1.6 WARRANTY

A. Special Warranty: Manufacturer agrees to replace components of units that fail in materials or workmanship within specified warranty period.

1. Warranty Period for Compressors: Five years from date of Substantial Completion.

2. Warranty Period for Heat Exchangers: 10 years from date of Substantial Completion.

PART 2 - PRODUCTS

2.1 MANUFACTURERS

A. Manufacturers: Subject to compliance with requirements, available manufacturers offering products that may be incorporated into the Work include, but are not limited to, the following:

1. AAON.

2. Addison.

3. Engineered Air.

4. Munters Corporation, Dehumidification Division; Des Champs Products.

2.2 CABINET

A. General Fabrication Requirements for Casings: Formed and reinforced 2” double-wall, R-13 insulated panels, fabricated to allow removal for access to internal parts and components, with joints between sections sealed.

B. Exterior Casing Material: G90 galvanized steel with factory-painted finish, with pitched roof panels and knockouts with grommet seals for electrical and piping connections.

1. Exterior Casing Thickness: 22 gauge.

2. As an alternative to the above casing gauge, the wall and roof deflection shall be within 1/240 of the span at a fan pressure of 8” wc.

C. Interior Casing Material: G90 Galvanized steel.

1. Interior Casing Thickness: 24 gauge.

2. As an alternative to the above casing gauge, the wall and roof deflection shall be within 1/240 of the span at a fan pressure of 8” wc.

D. Lifting and Handling Provisions: Factory-installed shipping skids and lifting lugs.

E. Base Rails: Galvanized -steel rails for mounting on roof curb or pad as indicated.

F. Access for Inspection, Cleaning, and Maintenance: Comply with requirements in

ASHRAE 62.1.

237433 - 3 DEDICATED OUTDOOR-AIR

1. Service Doors: Hinged access doors with gaskets. Material and construction of doors shall match material and construction of cabinet in which doors are installed.

G. Roof: Standing seam or membrane; sloped to drain water.

H. Floor: Reinforced, metal surface; reinforced to limit deflection when walked on by service personnel. Insulation shall be below metal walking surface.

I. Cabinet Insulation:

1. Type: Fibrous-glass duct lining complying with ASTM C 1071, Type II or flexible elastomeric insulation complying with ASTM C 534, Type II, sheet materials.

2. Thickness: 2 inches, R-13.

3. Insulation Adhesive: Comply with ASTM C 916, Type I.

4. Mechanical Fasteners: Suitable for adhesive, mechanical, or welding attachment to casing without damaging liner and without causing air leakage when applied as recommended by manufacturer.

J. Condensate Drain Pans:

1. Shape: Rectangular, with 1 percent slope in at least two planes to direct water toward drain connection.

2. Size: Large enough to collect condensate from cooling coils including coil piping connections, coil headers, and return bends.

a. Length: Extend drain pan downstream from leaving face to comply with

ASHRAE 62.1.

b. Depth: A minimum of 2 inches deep.

3. Configuration: Double wall, with space between walls filled with foam insulation and moisture-tight seal.

4. Material: Stainless-steel sheet.

5. Drain Connection:

a. Located at lowest points of pan.

b. Terminated with threaded nipple.

c. Pan-Top Surface Coating: Corrosion-resistant compound.

6. Units with stacked coils shall have an intermediate drain pan to collect condensate from top coil.

K. Surfaces in Contact with Airstream: Comply with requirements in ASHRAE 62.1 for resistance to mold and erosion.

L. Roof Curb: Full-perimeter curb of sheet metal, minimum 12 inches high, with wood nailer, neoprene sealing strip, and welded Z-bar flashing.

1. Comply with requirements in "The NRCA Roofing Manual."

M. Cabinet shall have pilot and main flame observation ports.

237433 - 4

2.3 SUPPLY/EXHAUST FANS

A. Forward-Curved Fan Type: Centrifugal; statically and dynamically balanced.

1. Fan Wheel Material: Coated steel, mounted on solid-steel shaft.

2. Bearings: Self-aligning, permanently lubricated ball bearings.

B. Plenum Fan Type: Single width, non-overloading, with backward-inclined or airfoil blades.

1. Fan Wheel Material: Aluminum; attached directly to motor shaft.

2. Fan Wheel Drive and Arrangement: Direct drive, AMCA Arrangement 4.

3. Fan panel and frame Material: Powder-coated steel, stainless steel, or aluminum.

4. Fan Enclosure: Easily removable enclosure around rotating parts.

5. Fan Balance: Precision balance fan below 0.08 inch/s at design speed with filter in.

C. Service Factor for Belt Drive Applications: V-belt drive with matching fan pulley and adjustable motor sheaves and belt assembly with minimum 1.4 service factor.

D. Motors:

1. VFD controlled and ECM driven supply and exhaust fans.

2. Comply with NEMA designation, temperature rating, service factor, and efficiency requirements for motors specified in Section 230513 "Common Motor Requirements for HVAC Equipment."

3. Enclosure Type: Totally enclosed, fan cooled.

4. NEMA Premium ™ efficient motors as defined in NEMA MG 1.

5. Motor Sizes: Minimum size as indicated. If not indicated, large enough so driven load will not require motor to operate in service factor range above 1.0.

6. Controller, Electrical devices, and Wiring: Comply with requirements for electrical devices and connections specified in electrical Sections.

7. Mount unit-mounted disconnect switches on exterior of unit.

E. Mounting: Fan wheel, motor, and drives shall be mounted to fan casing with spring isolators.

F. Each fan and motor combination shall be capable of delivering 110% of air quantity scheduled at the scheduled static pressure.

2.4 COOLING COILS

A. Capacity Ratings: Comply with ASHRAE 33 and ARI 410.

B. Coil Casing Material: Galvanized steel.

C. Tube Material: Copper.

D. Tube Header Material: Manufacturer's standard material.

E. Fin Material: Aluminum.

237433 - 5 DEDICATED OUTDOOR-AIR

F. Fin and Tube Joints: Mechanical bond.

G. Leak Test: Coils shall be leak tested with air underwater.

H. Refrigerant Coil Capacity Reduction: Circuit coils for interleaved control.

I. Refrigerant Coil Suction and Distributor Header Materials: Seamless copper tube with brazed joints.

J. Fabricate coil section to allow removal and replacement of coil for maintenance and to allow in-place access for service and maintenance of coil(s).

K. Cooling coils shall be sized and arranged to prevent moisture carryover. Cooling coils shall be sized for a maximum of 550 FPM face velocity. If two or more coils are stacked in the unit, intermediate drain channels shall be installed between coils to drain condensate to the main drain pans without flooding the lower coils or passing condensate through the airstream of the lower coil.

2.5 REFRIGERATION SYSTEM

A. Comply with requirements in ASHRAE 15, "Safety Standard for Refrigeration Systems."

B. Refrigerant Charge: Factory charged with refrigerant and filled with oil.

C. Compressors: Two hermetic, scroll compressors with integral vibration isolators, internal overcurrent and overtemperature protection, internal pressure relief, and crankcase heater.

D. Refrigerant: R-407C or R-410A.

1. Classified as Safety Group A1 according to ASHRAE 34.

2. Provide unit with operating charge of refrigerant.

E. Refrigeration System Specialties:

1. Expansion valve with replaceable thermostatic element.

2. Refrigerant dryer.

3. High-pressure switch.

4. Low-pressure switch.

5. Minimum off-time relay.

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

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

8. Low-ambient kit high-pressure sensor.

F. Capacity Control:

1. Digital scroll compressor control with compressor that can unload from 100% down to 10% capacity on a single compressor. Hot-gas bypass refrigerant

237433 - 6 control for capacity control on second compressor. Evaporator coil shall be continuously active for dehumidification.

G. Refrigerant condenser and reheat condenser coils:

1. Capacity Ratings: Complying with ASHRAE 33 and ARI 410.

2. Tube Material: Copper.

3. Fin Material: Aluminum.

4. Fin and Tube Joint: Mechanical bond.

5. Leak Test: Coils shall be leak tested with air underwater.

H. Condenser Fan Assembly:

1. Fans: Direct-drive propeller type with statically and dynamically balanced fan blades.

2. Fan Motors:

a. VFD controlled or ECM driven fans.

b. Comply with NEMA designation, temperature rating, service factor, and efficiency requirements for motors specified in Section 230513 "Common Motor Requirements for HVAC Equipment."

c. Motor Enclosure: Totally enclosed non-ventilating (TENV) or totally enclosed air over (TEAO) enclosure.

d. Enclosure Materials: Cast iron.

e. Motor Bearings: Permanently lubricated bearings.

f. Built-in overcurrent and thermal-overload protection.

g. Efficiency: Premium efficient.

h. NEMA Design: 4.

i. Service Factor: 1.15.

3. Fan Safety Guards: Steel with corrosion-resistant coating.

I. Safety Controls:

1. Compressor motor and condenser coil fan motor low ambient lockout.

2. Overcurrent protection for compressor motor.

J. Total Energy Recovery Wheels:

1. Casing:

a. Steel, with manufacturer's standard paint coating.

b. Integral purge section limiting carryover of exhaust air to between 0.05 percent at 1.6-inch wg and 0.20 percent at 4-inch wg differential pressure.

c. Casing seals on periphery of rotor, on duct divider, and on purge section.

d. Support rotor on grease-lubricated ball bearings with extended grease fittings. Mount horizontal wheels on tapered roller bearing.

2. Rotor: Aluminum or polymer based, segmented wheel, strengthened with radial spokes, with nontoxic, noncorrosive, silica-gel desiccant coating. Construct media for passing maximum 500-micrometer solids.

237433 - 7 DEDICATED OUTDOOR-AIR

3. Rotor: Segmented wheel, strengthened with radial spokes impregnated with nonmigrating, water-selective, molecular-sieve desiccant coating. Construct media for passing maximum 800-micrometer solids.

4. Drive: Fractional horsepower motor and gear reducer, with speed changed by variable frequency controller, and self-adjusting multilink belt around outside of rotor.

5. Controls:

a. Starting relay, factory mounted and wired, and manual motor starter for field wiring.

b. Variable frequency controller, factory mounted and wired, with exhaust-air sensor to vary rotor speed and maintain exhaust temperature above freezing.

c. Pilot-Light Indicator: Display rotor rotation and speed.

d. Speed Settings: Adjustable settings for maximum and minimum rotor speed limits.

2.6 INDIRECT-FIRED GAS FURNACE HEATING

A. Furnace Assembly:

1. Factory assembled, piped, and wired.

2. Comply with requirements in NFPA 54, "National Fuel Gas Code," and

ANSI Z21.47, "Gas-Fired Central Furnaces."

3. AGA Approval: Designed and certified by and bearing label of AGA.

B. Burners:

1. Heat-Exchanger Material: Stainless steel with a minimum thermal efficiency of 80 percent.

2. Fuel: Natural gas.

3. Ignition: Electronically controlled electric spark with flame sensor.

C. Heat-Exchanger Drain Pan Material: Stainless steel.

D. Venting: Power vent with integral, motorized centrifugal fan interlocked with gas valve.

E. Safety Controls:

1. Gas Control Valve: Electronic modulating.

2. Gas Train: Single-body, regulated, redundant, 24-V ac gas valve assembly containing pilot solenoid valve, pilot filter, pressure regulator, pilot shutoff, and manual shutoff.

2.7 OUTDOOR-AIR INTAKE HOOD

A. Type: Manufacturer's standard hood or louver.

B. Materials: Match cabinet.

C. Bird Screen: Comply with requirements in ASHRAE 62.1.

237433 - 8

D. Configuration: Designed to inhibit wind-driven rain and snow from entering unit.

2.8 FILTERS

A. Disposable Panel Filters:

1. Comply with NFPA 90A.

2. Factory-fabricated, viscous-coated, flat-panel type.

3. Thickness: 2 inches.

4. Initial Resistance: 0.3” wg.

5. Recommended Final Resistance: 0.9” wg.

6. Minimum Arrestance: 80, according to ASHRAE 52.1.

7. Minimum Merv: 8, according to ASHRAE 52.2.

8. Media: Interlaced glass fibers sprayed with nonflammable adhesive and antimicrobial agent.

B. Extended-Surface, Nonsupported-Media Filters:

1. Comply with NFPA 90A.

2. Factory-fabricated, dry, extended-surface, self-supporting type.

3. Initial Resistance: 0.5” wg.

4. Recommended Final Resistance: 1.3” wg.

5. Minimum Arrestance: 95, according to ASHRAE 52.1.

6. Minimum Merv: 13, according to ASHRAE 52.2.

7. Media: Fibrous material coated with an antimicrobial agent and constructed so individual pleats are maintained in tapered form by flexible internal supports under rated-airflow conditions.

C. Mounting Frames:

1. Panel filters arranged for flat or angular orientation, with access doors on both sides of unit. Filters shall be removable from one side or from access plenum.

2. Extended surface filters arranged for flat orientation, removable from access plenum.

3. Galvanized or stainless steel with gaskets and fasteners, suitable for bolting together into built-up filter banks with space for prefilter.

D. Maximum air velocity across filters shall not exceed 550 feet per minute.

2.9 ELECTRICAL POWER CONNECTIONS

A. Main disconnect switch, fuses, motor starter overloads, and control relays. Provide auxiliary contact on motor starter for fan motor control and exhaust fan interlocking.

B. General Electrical Power Connection Requirements: Factory-installed and -wired switches, motor controllers, transformers, and other necessary electrical devices shall provide a single-point field power connection to unit.

C. Enclosure: NEMA 250, Type 4, mounted in unit with hinged access door in unit cabinet having a lock and key or padlock and key, 237433 - 9 DEDICATED OUTDOOR-AIR

D. Wiring: Numbered and color-coded to match wiring diagram.

E. Wiring Location: Install factory wiring outside an enclosure in a raceway.

F. Power Interface: Field power interface shall be to single connection NEMA KS 1, heavy-duty, nonfused disconnect switch.

G. Factory Wiring: Branch power circuit to each motor and to controls with one of the following disconnecting means:

1. NEMA KS 1, heavy-duty, fusible switch with rejection-type fuse clips rated for fuses. Select and size fuses to provide Type 2 protection according to

IEC 60947-4-1.

2. NEMA KS 1, heavy-duty, nonfusible switch.

3. UL 489, motor-circuit protector (circuit breaker) with field-adjustable, short-circuit trip coordinated with motor locked-rotor amperes.

H. Factory-Mounted, Overcurrent-Protection Service: For each motor.

I. Transformer: Factory mounted with primary and secondary fuses and sized with enough capacity to operate electrical load plus spare capacity.

J. Controls: Factory wire unit-mounted controls where indicated.

K. Receptacle: Factory wire unit-mounted, ground fault interrupt (GFI) duplex receptacle.

L. Control Relays: Auxiliary and adjustable time-delay relays.

2.10 CONTROLS

A. Control equipment and sequence of operation are specified in Section 230900 "Instrumentation and Control for HVAC."

B. Control Valves: Comply with requirements in Section 230900 "Instrumentation and Control for HVAC."

C. Control Wiring: Factory wire connection for controls' power supply.

D. Control Devices: Sensors, transmitters, relays, switches, detectors, operators, actuators, and valves shall be manufacturer's standard items to accomplish indicated control functions.

E. Remote-Mounted Status Panel:

1. Cooling/Off/Heating Controls: Control operational mode.

2. Damper Position: Indicate position of outdoor-air dampers in terms of percentage of outdoor air.

3. Status Lights:

a. Filter dirty.

b. Fan operating.

c. Cooling operating.

237433 - 10

d. Heating operating.

e. Smoke alarm.

f. General alarm.

4. Digital Numeric Display:

a. Outdoor airflow as cfm.

b. Outdoor dry-bulb temperature.

c. Outdoor dew point temperature.

d. Space temperature.

e. Supply temperature.

f. Space relative humidity.

F. Control Dampers:

1. Outdoor- and Exhaust-Air Dampers: Low-leakage, double-skin, airfoil-blade, galvanized-steel dampers with compressible jamb seals and extruded-vinyl blade edge seals in parallel blade arrangement with cadmium-plated steel operating rods rotating in stainless-steel sleeve bearing mounted in a single galvanized-steel frame, and with operating rods connected with a common linkage. Leakage rate shall not exceed 5 cfm/sq.ft at 1-inch wg and 9 cfm/sq.ft. at 4-inch wg.

G. Refrigeration System Controls:

1. Unit-mounted enthalpy controller shall lock out refrigerant system when outdoor-air enthalpy is less than 28 Btu/lb of dry air or outdoor-air temperature is less than 60 deg F.

2. Outdoor-air sensor de-energizes dehumidifier operation when outdoor-air temperature is less than 60 deg F.

3. Relative-humidity sensor energizes dehumidifier operation when relative humidity is more than 50 percent.

H. Furnace Controls:

1. Factory-mounted sensor in supply outlet with sensor adjustment located in control panel to modulate gas furnace burner to maintain space temperature.

2. Electromechanical or Electronic Burner Control: 20 to 100 percent modulation of the firing rate; 10 to 100 percent with dual-furnace units.

I. Integral Smoke Alarm: Smoke detector installed in supply and exhaust air.

J. DDC Temperature Control: Standalone control module for link between unit controls and DDC temperature-control system. Control module shall be compatible with control system specified in Section 230900 "Instrumentation and Control for HVAC." Links shall include the following:

1. Start/stop interface relay, and relay to notify DDC temperature-control system alarm condition.

2. Hardware interface or additional sensors for the following:

a. Discharge-air temperature.

237433 - 11 DEDICATED OUTDOOR-AIR

b. Refrigeration system operating.

c. Furnace operating.

d. Constant and variable motor loads.

e. Variable-frequency-controller operation.

f. Cooling load.

g. Air-distribution static pressure and ventilation-air volumes.

K. BAS Interface: Factory-installed hardware and software to enable the BAS to monitor, control, and display unit status and alarms.

1. Hardwired Points:

a. Monitoring: On-off status, common trouble alarm.

b. Control: On-off operation, supply temperature set-point adjustment space humidity set-point adjustment.

2. ASHRAE 135 (BACnet) communication interface with the BAS shall enable the BAS operator to remotely control and monitor the unit from an operator workstation. Control features and monitoring points displayed locally at unit control panel shall be available through the BAS.

2.11 ACCESSORIES

A. Duplex Receptacle: Factory mounted in unit supply-fan section, with 20 amp 120 V GFI duplex receptacle and weatherproof cover.

PART 3 - EXECUTION

3.1 EXAMINATION

A. Examine substrates, areas, and conditions, with Installer present, for compliance with requirements for installation tolerances and other conditions affecting performance of the Work.

B. Examine roughing-in for piping, ducts, and electrical systems to verify actual locations of connections before equipment installation.

C. Examine roof curbs and equipment supports for suitable conditions where units will be installed.

D. Proceed with installation only after unsatisfactory conditions have been corrected.

3.2 INSTALLATION

A. Comply with manufacturer's rigging and installation instructions for unloading units and moving to final locations.

B. Curb Support: Install roof curb on roof structure according to "The NRCA Roofing Manual."

237433 - 12

1. Install and secure units on curbs and coordinate roof penetrations and flashing with roof construction.

2. Coordinate size, installation, and structural capacity of roof curbs, equipment supports, and roof penetrations. These items are specified in Division 07.

3. Coordinate size, location, and installation of unit manufacturer's roof curbs and equipment supports with roof Installer.

C. Equipment Mounting:

1. Comply with requirements for vibration isolation devices specified in Section 230548.13 "Vibration Controls for HVAC."

D. Install wall- and duct-mounted sensors furnished by manufacturer for field installation.

Install control wiring and make final connections to control devices and unit control panel.

E. Install 3000-psi, compressive-strength (28-day) concrete base inside roof curb, 4 inches thick. Concrete and reinforcement are specified with concrete.

F. Comply with requirements for gas-fired furnace installation in NFPA 54, "National Fuel Gas Code."

G. Install separate devices furnished by manufacturer and not factory installed.

H. Install new filters at completion of equipment installation and before testing, adjusting, and balancing.

I. Install drain pipes from unit drain pans to sanitary drain.

1. Drain Piping: Drawn-temper copper water tubing complying with ASTM B 88, Type L, with soldered joints.

2. Drain Piping: Schedule 40 PVC pipe complying with ASTM D 1785, with solvent-welded fittings.

a. PVC solvent cement shall have a VOC content of 510 g/L or less when calculated according to 40 CFR 59, Subpart D (EPA Method 24).

b. Adhesive primer shall have a VOC content of 550 g/L or less when calculated according to 40 CFR 59, Subpart D (EPA Method 24).

c. Solvent cement and adhesive primer shall comply with the testing and product requirements of the California Department of Health Services' "Standard Practice for the Testing of Volatile Organic Emissions from Various Sources Using Small-Scale Environmental Chambers."

3. Pipe Size: Same size as condensate drain pan connection.

J. Clean dust and debris from each unit as it is installed.

K. Install units on flat surface level within 1/8" and of sufficient strength to support the units.

3.3 CONNECTIONS

237433 - 13 DEDICATED OUTDOOR-AIR

A. Where installing piping adjacent to units, allow space for service and maintenance.

B. Gas Piping Connections:

1. Comply with requirements in Section 231123 "Facility Natural-Gas Piping."

2. Connect gas piping to furnace, full size of gas train inlet, and connect with union and shutoff valve with sufficient clearance for burner removal and service.

3. Install AGA-approved flexible connectors.

C. Duct Connections:

1. Comply with requirements in Section 233113 "Metal Ducts."

2. Drawings indicate the general arrangement of ducts.

3. Connect ducts to units with flexible duct connectors. Comply with requirements for flexible duct connectors in Section 233300 "Air Duct Accessories."

4. Ensure that metal bands of connectors are parallel with minimum one inch flex between ductwork and fan while running.

D. Electrical Connections: Comply with requirements for power wiring, switches, and motor controls in electrical Sections.

1. Install electrical devices furnished by unit manufacturer but not factory mounted.

E. Where inlet and outlet ductwork at any fan is changed from that shown on drawings, submit scaled layout of the change and system effect factor calculations, indicating increased static pressure requirement as described in AMCA Publication 201. The Contractor shall be responsible for any motor, drive, and/or wiring changes required as result of duct configuration changes at fan. . In all cases obtain Approval before proceeding with changes to ductwork.

F. If objectionable noise or vibration is produced or transmitted to or through the building structure by equipment piping, ducts, or other parts of the work, the Contractor shall rectify such conditions without cost to the Contract. If the item of equipment is judged to produce objectionable noise or vibration, demonstrate without cost to the Contract that the equipment performs within the designated vibration limits specified.

3.4 STARTUP SERVICE

A. Engage a factory-authorized service representative to perform startup service.

1. Complete installation and startup checks according to manufacturer's written instructions.

2. Inspect units for visible damage to furnace combustion chamber.

3. Perform the following operations for both minimum and maximum firing and adjust burner for peak efficiency:

a. Measure gas pressure at manifold.

b. Measure combustion-air temperature at inlet to combustion chamber.

c. Measure flue-gas temperature at furnace discharge.

d. Perform flue-gas analysis. Measure and record flue-gas carbon dioxide and oxygen concentration.

237433 - 14

e. Measure supply-air temperature and volume when burner is at maximum firing rate and when burner is off. Calculate useful heat to supply air.

4. Verify operation of remote panel including pilot-light operation and failure modes.

Inspect the following:

a. High-limit heat exchanger.

b. Alarms.

5. Inspect units for visible damage to refrigerant compressor, condenser and evaporator coils, and fans.

6. Start refrigeration system when outdoor-air temperature is within normal operating limits and measure and record the following:

a. Cooling coil leaving-air, dry- and wet-bulb temperatures.

b. Cooling coil entering-air, dry- and wet-bulb temperatures.

c. Condenser coil entering-air dry-bulb temperature.

d. Condenser coil leaving-air dry-bulb temperature.

7. Simulate maximum cooling demand and inspect the following:

a. Compressor refrigerant suction and hot-gas pressures.

b. Short-circuiting of air through outside coil or from outside coil to outdoor-air intake.

8. Inspect casing insulation for integrity, moisture content, and adhesion.

9. Verify that clearances have been provided for servicing.

10. Verify that controls are connected and operable.

11. Verify that filters are installed.

12. Clean coils and inspect for construction debris.

13. Clean furnace flue and inspect for construction debris.

14. Inspect operation of power vents.

15. Purge gas line.

16. Inspect and adjust vibration isolators and seismic restraints.

17. Verify bearing lubrication.

18. Clean fans and inspect fan-wheel rotation for movement in correct direction without vibration and binding.

19. Adjust fan belts to proper alignment and tension.

20. Start unit.

21. Inspect and record performance of interlocks and protective devices including response to smoke detectors by fan controls and fire alarm.

22. Operate unit for run-in period.

23. Calibrate controls.

24. Adjust and inspect high-temperature limits.

25. Inspect outdoor-air dampers for proper stroke and interlock with exhaust-air dampers.

26. Verify operational sequence of controls.

27. Measure and record the following airflows. Plot fan volumes on fan curve.

a. Supply-air volume.

b. Exhaust-air flow.

237433 - 15 DEDICATED OUTDOOR-AIR

c. Outdoor-air flow.

B. After startup, change filters, verify bearing lubrication, and adjust belt tension.

C. Remove and replace components that do not properly operate and repeat startup procedures as specified above.

D. Prepare written report of the results of startup services.

3.5 ADJUSTING

A. Adjust initial temperature and humidity set points.

B. Set field-adjustable switches and circuit-breaker trip ranges as indicated.

3.6 DEMONSTRATION

A. Engage a factory-authorized service representative to train Government’s maintenance personnel to adjust, operate, and maintain units.

END OF SECTION 237433