Specifications for Dedicated Outdoor-Air Units

PART 1 -GENERAL

1.3 RELATED DOCUMENTS

A. Section 230513 “Common Motor Requirements for HVAC Equipment.”

B. Section 230900 “Instrumentation and Control for HVAC.”

1.4 SUMMARY

A. Dedicated Outdoor Air Unit (DOAU) shall be owner furnished, contractor installed. Unit shall be stored by manufacturer for a maximum of 3 weeks after unit is manufactured until item is shipped to the site, Buist Residence Hall, 13 College Way, Charleston, SC 29401 such that it can be installed on May 2, 2016. Vendor shall include cost of delivery to the site as an option. College may opt to have manufacturer ship as quoted or make their own arrangements for shipping.

B. Section includes factory-packaged units capable of supplying up to 100 percent outdoor air and providing cooling and heating.

C. This section includes Packaged Air-to-Air Energy Recovery Units with integral heating and cooling for rooftop installation.

D. Integral heat source shall be Indirect Gas-Fired furnace

E. Integral cooling source shall be chilled water

F. Airflow arrangement shall be Outdoor Air only.

G. Within this document, these units may be referred to as Energy Recovery Unit (ERU) for brevity. Each unit shall be constructed in a horizontal configuration and shall incorporate additional product requirements as listed in Section 2 of this specification.

1.5 ACTION SUBMITTALS

A. Vendor shall obtain written document indicating Engineer of Record’s review, and incorporate comments before unit is released.

B. Product Data: For each type or model of Packaged Air-to-Air Energy Recovery Unit with Integral heating and cooling, include the following:

1. Complete fan performance curves for both Supply Air and Exhaust Air, with system operating conditions indicated, as tested in an AMCA Certified Chamber.

2. Sound performance data for both Supply Air and Exhaust Air, as tested in an AMCA Certified chamber.

3. Energy wheel performance data for both summer and winter operation.

4. AHRI Certified coil performance ratings with system operating conditions indicated. Ratings shall be in accordance with Standard 410.

5. Motor ratings, electrical characteristics and motor and fan accessories.

6. Combined efficiency data per ARI Guideline V-2003 for each model. Data shall include RER, COP, Unitary Net Cooling, Unitary EER and CEF.

7. Material types and gauges of all component pieces and assemblies.

8. Dimensioned drawings for each type of installation, showing isometric and plan views, to include location of attached ductwork and service clearance requirements.

9. Estimated gross weight of each installed unit.

10. Installation, Operating and Maintenance manual (IOM) for each model.

11. Microprocessor Controller specifications to include available options and operating protocols. Include complete data on all factory-supplied input devices.

C.Delegated-Design Submittal: For design of seismic restraints and wind restraints, including analysis data signed and sealed by the qualified professional engineer responsible for their preparation.

1. Unit fabrication and assembly details.

2. Seismic Restraint Base Details: Detail fabrication including anchorages and attachments to structure and to supported equipment. Include adjustable motor bases, rails, and frames for equipment mounting.

3. Design Calculations:

a.Calculate requirements for selecting seismic restraints and wind restraints and for designing vibration isolation bases.

b. Indicate compliance with "Performance Requirements" article.

4. Seismic Curb shall be furnished by the unit manufacturer or vendor. Vendor shall be responsible for seismic calculations, stamped shop drawings, and submittal information for the seismic curb. All shipping and storage information listed above for DOAU shall be applicable. The curb height shall be assumed to be 18”.

1.6 INFORMATIONAL SUBMITTALS

A. Coordination Drawings: Roof-curb mounting details, drawn to scale, on which the following items are shown and coordinated with each other, using input from installers of the items involved:

  1. Size and location of unit-mounted rails and anchor points and methods for anchoring units to roof curb.
  2. Required roof penetrations for ducts, pipes, and electrical raceways, including size and location of each penetration.

B. Seismic Qualification Certificates: For dedicated outdoor-air units, accessories, and components, from manufacturer.

  1. Basis for Certification: Indicate whether withstand certification is based on actual test of assembled components or on calculation.
  2. Dimensioned Outline Drawings of Equipment Unit: Identify center of gravity and locate and describe mounting and anchorage provisions.
  3. Detailed description of equipment anchorage devices on which the certification is based and their installation requirements.

C. Startup service reports.

D. Sample Warranty.

1.7 CLOSEOUT SUBMITTALS

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

1.8 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 Heat Exchangers: Five years from date of Substantial Completion.

1.7 QUALITY ASSURANCE

A. Source Limitations: Obtain Packaged Air-to-Air Energy Recovery Unit with all appurtenant components or accessories from a single manufacturer.

B. Product Options: Drawings must indicate size, profiles and dimensional requirements of Energy Recovery Units and are to be based on the specific system indicated. Refer to Division 1 Section "Product Requirements".

C. Certifications

  1. Blowers shall be AMCA Certified for air flow.
  2. Entire unit shall be ETL Certified per U.L. 1995 and bear an ETL sticker.
  3. Energy Wheel shall be AHRI Certified, per Standard 1060.
  4. Coils shall be Recognized Components for ANSI/UL 1995, CAN / CSA C22.2 No 236.05. DX and water coils shall be AHRI Certified per standard 410-2001.

D. Indirect gas-fired furnace shall be ETL Certified as a component of the ERU. Indirect gas-fired furnace shall be an ETL Recognized Component of the ERU per ANSI Z83.8.

PART 2 -PRODUCTS

2.3 GENERAL

A. Packaged Air-to-Air Energy Recovery Units shall be fully assembled at the factory and consist of an insulated metal cabinet, with engineered seismic curb kit, motorized insulated low leakage intake damper, filter assemblies for both intake and exhaust air, energy wheel, airside coil, engineered P trap assembly with P trap, water coil, supply air blower assembly, indirect gas-fired furnace, insulated low leakage exhaust air damper, exhaust air blower assembly electrical control unit with all specified components and internal accessories factory installed and tested and prepared for single-point high voltage connection. Entire unit with the exception of field-installed components shall be assembled and test operated at the factory.

B. Basis-of-Design Product: Subject to compliance with requirements, provide product indicated in attached cutsheet or comparable product by one of the following:

  1. Munters Corporation, Dehumidification Division; Des Champs Products.
  2. Annexaire
  3. Venmar
  4. Greenheck
  5. Or equal

2.4 PERFORMANCE REQUIREMENTS

A. General Fabrication Requirements: Comply with requirements in ASHRAE 62.1, Section 5 "Systems and Equipment," and Section 7 -"Construction and System Start-up."

B. Seismic Performance: Units shall withstand the effects of earthquake motions determined according to ASCE/SEI 7.

  1. The term "withstand" means "the unit will remain in place without separation of any parts when subjected to the seismic forces specified."

C. Wind-Restraint Performance:

  1. Basic Wind Speed: 140
  2. Minimum 10 lb/sq. ft multiplied by the maximum area of unit projected on a vertical plane that is normal to the wind direction and 45 degrees either side of normal.

D. Cabinet:

  1. Materials: Formed, insulated double wall construction, fabricated to permit access to internal components for maintenance.

a. Outside casing: 18 gauge, galvanized (G90) steel with painted basis of design GreenheckPermatector or equal.

b. Internal assemblies: except for motor supports which shall be 14 gauge galvanized (G90) steel.

E. Maximum Cabinet Leakage: 2 percent or less of the total supply-air flow at a pressure rating equal to the fan shut-off pressure.

F. Electrical components, devices, and accessories: Listed and labeled as defined in NFPA 70, by a qualified testing agency, and marked for intended location and application.

2.5 CABINET

A. Construction: double wall.

B. Exterior Casing Material: 18 gauge Galvanized steel (G90) painted with basis of design GreenheckPermatector or equal.

C. Interior Casing Material: 14 gauge Galvanized steel.

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.

  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. Comply with NFPA 90A and NFPA 90B and erosion requirements of UL 181.

1. Materials: Fiberglass insulation. If insulation other than fiberglass is used, it must also meet the Fire Hazard Classification shown below.

a. Thickness: 1 inch

b. Fire Hazard Classification: Maximum flame spread of 25 and smoke developed of 50, when tested in accordance with ASTM C 411.

c. Location and application: Full coverage of entire cabinet exterior to include walls and roof of unit. Insulation shall be of semi-rigid type and installed between inner and outer shells of all cabinet exterior components.

2. Materials: Rigid urethane foam

a. Thickness: 1 inch

b. Meets UL94HF-1 flame requirements.

c. Location and application: Doors and the floor of the unit.

J. Condensate Drain Pans: Pan shall be formed of welded austenitic stainless steel sheet material and provided with a welded drain connection at the front for connection to a P trap. Drain pan shall be sloped in two directions to provide positive draining.

K. P trap: An engineered P trap (condensate drain) assembly shall be provided for each unit, to include cleanout ports, cleanout tool, vacuum break device and see-through reservoir to permit visual verification of water or glycol solution levels.

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

M. Seismic Rated Roof Curb: Full-perimeter curb of sheet metal, minimum 18 inches high, with wood nailer, neoprene sealing strip, and welded Z-bar flashing.

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

2.6 Energy wheel

A. Energy wheel shall be of total enthalpy, rotary air-to-air type and shall be an element of a removable energy wheel

cassette. The cassette shall consist of a galvanized steel framework (designed to produce laminar air flow through the wheel), an energy wheel as specified and a motor and drive assembly. The cassette shall incorporate a pre-tensioned urethane drive belt with a five year warranty. The wheel media shall be a polymer film matrix in a stainless steel framework and be comprised of individual segments that are removable for servicing. Non-segmented energy wheels are not acceptable. The polymer film material shall be coated with silica gel desiccant and shall be designed and constructed to permit cleaning and servicing. The energy wheel is to have a five year warranty. Performance criteria are to be as specified in AHRI Standard 1060, complying with the Combined Efficiency data in the submittal.

2.7 SUPPLY AND EXHAUST FANS

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

  1. Fan Wheel Material: Galvanized steel or aluminum, mounted on solid-steel shaft.
  2. Bearings: Self-aligning, permanently lubricated ball bearings.

B. Service Factor for Belt Drive Applications: V-belt drive with matching fan pulley and adjustable motor sheaves and belt assembly with minimum 1.5 service factor.

C. Motors:

1. Comply with NEMA designation, temperature rating, service factor, and efficiency requirements for motors

specified in Section 230513 "Common Motor Requirements for HVAC Equipment."

2 Enclosure: Totally enclosed.

  1. Efficiency: Premium efficient.
  2. Service Factor: 1.15.

D. Mounting: Fan wheel, motor, and drives shall be mounted to fan casing with neoprene vibtration isolators.

2.8 COOLING COILS

A. Water Coil: A water coil for cooling shall be factory-installed in the ERU for connection to a building water source.

B. Capacity Ratings: Comply with ASHRAE 33 and ARI 410 and coil bearing the ARI label.

C. Coil Casing Material: Aluminum.

D. Tube Material: Copper.

E. Tube Header Material: Copper.

F. Fin Material: Aluminum.

G. Fin and Tube Joints: Mechanical bond.

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

I. Coating: Phenolic epoxy corrosion-protection coating after assembly.

2.9 INDIRECT-FIRED GAS FURNACE HEATING

A. Shall be ETL Certified as a component of the Energy Recovery Air Unit. Shall have an integral exhaust gas blower. Shall be ETL Certified for installation downstream of a cooling coil. Shall have fault sensors to provide fault conditions to optional digital controller or building controls. Shall have 4-pass tubular heat exchangers, constructed of type 409 stainless steel. Heat exchanger tubes shall be installed on the vest plate by means of swaged assembly, welded connections are not acceptable. Heat exchanger tubes shall be supported by a minimum of two fabricated assemblies that support the tubes and also permit expansion and contraction of the tubes.

B. Furnace control shall be 4:1 Modulating. Shall have solid state controls permitting stand-alone operation or control by building controllers.

C. 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.

D. 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.

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

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

G. 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.

2.10 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.

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

2.11 FILTERS

A. Energy Recovery Unit shall have permanent metal filters located in the outdoor air intake and shall be accessible from the exterior of the unit. MERV 8 pleated filters shall be provided in the intake air stream and MERV 8 filters in the exhaust air stream.

2.12 ELECTRICAL POWER CONNECTIONS

A. 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.

B. Enclosure: NEMA 250, Type 3R, mounted in unit with hinged access door in unit cabinet having a lock and key or padlock and key,

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

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

E. 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.

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

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

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

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

2.13 CONTROLS

A. Unit shall be provided with factory mounted internal microprocessor control panel compatible with existing campus building automation system. Vendor shall confirm communications protocol with Ed Reamer (803-351-0895) before releasing equipment, but shall be assumed to be Siemens and BACnet compliant. Unit shall include items indicated on attached cutsheet and shall also include the following:

  1. LCD readout for changing set points and monitoring unit operation
  2. Outdoor Air Intake Temperature Sensor
  3. Outdoor Air discharge temperature sensor
  4. After cooling coil temperature sensor
  5. Exhaust and Supply Dirty filter pressure switches
  6. Exhaust Air after wheel temperature sensor
  7. Outdoor air after wheel temperature sensor
  8. Return air intake temperature sensor

B. Control panel / connections: Energy Recovery Unit shall have an electrical control center where all high and low voltage connections are made. Control center shall be constructed to permit single-point high voltage power supply connections.

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

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

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

F. Unit-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:
  1. Filter dirty.
  2. Fan operating.
  3. Cooling operating.
  4. Heating operating.
  5. Smoke alarm.
  6. General alarm.
  1. Digital Numeric Display:
  1. Outdoor airflow.
  2. Exhaust airflow
  3. Outdoor dry-bulb temperature.
  4. Outdoor dew point temperature.
  5. Supply air temperatures.
  6. Space relative humidity.

G. Control Dampers: