Custom AHU

7/30/2019 Custom AHU

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SECTION 23 73 23 - CUSTOM AIR HANDLING UNITS

PART I - GENERAL

1.1 SUBMITTALS [AE to edit this paragraph to be project specific, without deleting or omitting thefollowing intent.]

A. Show all internal floor, wall, and roof support, beams, and columns.

B. Provide dimensioned computer generated drawings showing unit plan, elevation views, allinternal components, wall and floor penetrations, structural frame design, and unit weightsat lifting lugs. Drawings shall be a minimum of =1-0 scale.

C. Detail connection of the base of the unit as it sits on the curb or support steel. Providecalculation(s) confirming minimum elevation for the (P-trap) drain(s) for appropriate unitdraining and clearance above unit.

D. Detail connection of shipping splits.

E. Provide fan curves with specified operating point clearly plotted, 8 octave band sound

power produced, and motor loading.F. Indicate fan class, performance, and motor electrical characteristics, metal gauges,

material finishes, assembly, construction details, and field connection details.

G. Provide calculated 8 octave maximum sound power levels at unit discharge and returnconnection, and maximum casing radiated sound power levels.

H. Provide static pressure calculations including individual internal component pressurelosses (including clean filters and separate allowance for loaded dirty filters) andavailable external static pressure. Total internal pressure drop shall not exceed valuesscheduled. External static pressure shall not be less than values scheduled. Provideoperating point and motor BHP and amp loading due to Design total static pressure (TSP)including allowance for loaded (dirty) filters.

I. Submit installation, and operation and maintenance data. Include instructions forlubrication, filter replacement, motor and drive replacement, and spare parts lists.

J. Submit certified factory leakage test results showing actual test data.

1.2 WARRANTY

A. Provide a manufacturers parts and labor warranty against factory defects in material andworkmanship for the entire unit for a period of 1 year after startup or 18 months fromshipment, whichever has the farthest date.

B. Provide an extended manufacturers warranty for a period of oneyear beyond thewarranty period listed above against factory defects in material and workmanship(including paint) for the entire unit.

C. Energy Recovery Wheels shall carry a full parts and labor warranty for (5) years from the

date of shipment. The extended warranty shall cover both thermodynamic performanceand mechanical operation of the entire rotating assembly except for belts, motor, and ACfrequency inverter. The manufacturer of the total Energy Recovery Wheel Transfer Media(not employees of the contractor or wheel casing fabricators that purchase the transfermedia from others) shall provide field service engineer for start-up adjustment andcalibration of controls, and instruction to operating personnel, and for annual inspectionand documentation of thermodynamic performance and mechanical operation for the

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ADDENDUM NO. 2 LAST UPDATED NOVEMBER 1, 2011

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duration of the warranty period. [Note to AE in regard to special warranty: Bearings shallnot fail (seize or otherwise malfunction) causing operational unit failure or adverse rotatingdeflection of the wheel for a minimum (10) continuous operating years.]

1.3 EXTRA STOCK

A. Preoccupancy Building Purge: Provide one set of Type D and one set of Type H filters ineach unit for preoccupancy building purge.

B. Extra stock: Provide one additional set of Type D replacement filters for all units beyondsets listed above.

C. Belt driven units provide exchange sets for TAB work.

D. Units shall not be used during and/or for Construction. If units are used during flush out,provide all new filters (described under internal components) and after purge prior tooccupancy. Coordinate and provide additional filters set(s) weekly (or sooner) as loadingrequires for compliance during allowed use (not in conflict with LEED) of permanentequipment.

1.4 GENERAL DESCRIPTION

A. Installation:

[Note to AE: For Projects requiring or potentially requiring knock down units for fieldassembly:

1. Insert language requiring units must ship knocked down for field assembly of panelsinside the mechanical room when so required.

2. Pending application, Design may require Factory assembly and witnessed or certifiedpressure/leak testing prior to disassembly and shipping.

3. Require adequate component tagging and re-assembly instructions and/or Factorysupervision during Field re-assembly.

4. Require the same field test(s) as defined elsewhere in this Section.

5. Related conflicts attributed to knock-down requirement shall not give cause foradditional costs to the Owner or Project.]

PART 2 - PRODUCTS

2.1 ACCEPTABLE MANUFACTURERSA. Equipment type in parentheses ( ) indicates only those specific components. Refer to the

paragraph entitled INTERNAL COMPONENTS - Energy Recovery Wheel for additionallimitations on Energy Recovery Wheel Providers.

B. All indoor and outdoor (DOA) Dedicated Outdoor Air Units and Central Station (AHU) AirHandling Units, single or dual wheel applications i.e. any combination Total - Totalconfiguration of wheels, Total - Sensible configuration, Sensible - Sensible configuration asper the Design Intent.

C. General Listing does not automatically pre-approve / approve components.

1. Air Enterprise.

2. Air Flow Equipment.

3. Climatecraft.

4. Concepts and Design, Inc.

5. Engineered Air, Inc.

6. Haakon Industries Ltd.



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7. Huntair.

8. Ingenia, Inc.

9. Marcraft, Inc.

10. SEMCO.

11. Venmar.

12. Ventrol.

2.2 GENERAL UNIT ENVELOPE

A. Thermal Resistance:

1. Walls and Roof Manufacturer shall meet the more stringent of:

a. Panels, joints, and seams shall be thermally broken. Thermal break shall consist of arigid EPDM or neoprene separation between the interior and exterior wall panelswithout direct metal to metal bridging.

b. All panels shall be at least 3 inches thick without diminishing the minimum insulatingvalue or compromising the Thermal Resistance intent of this Section.

c. Insulation material shall be non-wicking, non-absorbing of fluids, and not promote orsustain microbial growth.

d. Exterior panels of conditioned sections shall not condense given the following

conditions: supply air conditions: 52F; exterior unit conditions: 95Fdb/78Fwb.Manufacturer shall submit documentation demonstrating ability to prohibitcondensation.

e. Assembly shall be rated with a flame spread of less than 25 and a smoke developedof less than 50 when rated in accordance with ASTM E87 as required by NFPA forHVAC components.

f. Panels shall not frost given the following conditions: supply air conditions: 70F db30%rh; exterior unit conditions: -7Fdb. Manufacturer shall submit documentationdemonstrating ability to prohibit frosting.

2. Floors:

a. Floors shall be a minimum of 4 thick and meet the same criteria as in A.1 Thermal

Resistance.b. Floor insulation shall be non-wicking, non-absorbing of fluids, and not promote or

sustain microbial growth.

c. Combined height of house-keeping pad plus floor depth and associated base railingshall be of sufficient depth to allow for traps to function properly.

B. Deflection:

1. Structural reinforcement shall be designed so no member or assembly exceeds adeflection of 1/200 of span based on equipment loading and differential static of 8W.C.

C. Leakage Rate/Pressure Rating:

1. Leakage Rate:

a. The entire exterior unit casing shall be a constructed with an absolute leakage of 1%of design CFM when tested at 8 W.C.

b. Manufacturer shall submit certified documentation along with Shop DrawingSubmittals stating their construction standards are within these leakagerequirements.



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c. Housing construction shall utilize EPDM or neoprene foam gaskets at joints, seams,and split points as the pressure seal. All Units shall be field tested. Split shipmentfield assembled and/or knocked down units field assembled units shall be fieldtested after completed field assembly. The test shall be performed at the specifiedtest pressure with the leakage rate not exceeding the same % leakage specified.

2.3 ALTERNATE MATERIALS (FRAME, STRUCTURE, FLOOR, PANELS, ROOF, LINERS)

A. Critical care shall be taken when selecting materials to prevent deflection or oil canning,and to optimize thermal performance and rigidity.

B. Excluding all Stainless Steel requirements; Structural/Sheet Aluminum/Alloy may besubstituted for Steel (structure / sheet) based on third party documentation included withSubmittals proving equal structural rigidity, deflection and performance as intended in thisSection.

C. Regardless of materials used, Unit shall be constructed to prevent oil canning at 250lbs/sq.ft. point loading at center of component or panel.

2.4 UNIT FRAME

A. Floor Structure:

1. Perimeter floor frame and members shall be welded cold formed carbon steel usingstandard shapes and sizes.

2. Finish frame after fabrication with minimum of 1.5 mils of corrosion resistant epoxy

primer with pencil hardness B. Adhesion shall comply with ASTM D-3359-B with nolifting.

2.5 FLOOR CONSTRUCTION

A. Floor Plates/Sheets:

1. Tread plate style or otherwise for non-slip design.

2. When using steel, floor plates/sheets shall be a minimum of 12 gauge with a rustresistive non-slip epoxy finish tread plate.

3. When using stainless steel, floor plates/sheets shall be a minimum of 12 gauge treadplate. Treat with compatible surface preparation when adding non-slip epoxy finish (forwet walkable surfaces).

4. When using aluminum, floor sheets shall be ASTM B209 with non-slip design.B. Floor to Adjacent Wall Connection:

1. Floor shall be continuously sealed with closed cell EPDM (or equal) gasket to the wallpanels.

C. Floor Plate/Sheet to Floor Plate/Sheet Connection:

1. Floor-to-floor connections may be turned up and bolted (only with seal-tight gaskets).

D. Floor Plate/Sheet to Unit Base Connection:

1. Floor may be screwed (with gasket type washers) or tack welded to unit basemaintaining thermal break.

2. Floors shall be constructed to prevent oil canning at 250 lbs/sq.ft. point loading at

center of panel.3. Standing seams or ridges at the floor are not permitted in vestibules or in walkable

access sections.

2.6 EXTERIOR WALL CONSTRUCTION

A. Interior Liner:



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1. Interior liner shall be bright ASTM A90 and A653 G60 galvanized steel and shall remainunpainted.

2. Interior liner shall be a minimum of 22 gauge solid sheets.

B. Exterior Shell:

1. Exterior shell shall be 16 gauge ASTM A90 and A653 G90 galvanized steel.

2. Exterior shell shall be a galv-annealed finish.

2.7 ROOF CONSTRUCTION

A. Interior Liner:

1. Interior liner shall be bright ASTM A90 and A653 G60, 22 gauge galvanized steel andshall remain unpainted.

B. Exterior Shell:

1. Exterior shell shall be 16 gauge ASTM A90 and A653 G90 galvanized steel.

2. When roof seams are utilized, standing seams or ridges shall withstand 1.5 inches ofstanding water without oil canning or leaking into the insulation unit interior.

2.8 MULTI-SECTION UNITS:

A. Design and manufacture units to facilitate field assembly with no field redesign or re-drilling of holes.

B. Provide non-permeable gasketing at all split joints. Caulking is not permitted at shippingsplits.

C. Flanged perimeter metal and gasket shall be drilled with assembly holes.

D. Gaskets shall be high quality weather resistant closed cell non-permeable neoprene rubber.

2.9 DOORS

A. Comply with the same thermal resistance performance as walls and Roofs.

B. Unit doors shall be double wall and insulated with the same materials used in thesurrounding unit walls.

C. Door frames shall be continuously welded and formed of the same materials as thesurrounding wall.

D. Doors shall contain a continuous neoprene bulb type gasket.

E. Each door shall have minimum of two (2), 6 butt hinges.

F. Each door shall have a minimum of two (2) high compression type latches, operable fromboth sides. All exterior doors shall have a securable padlock fitting.

G. Each door shall contain a double pane tempered, reinforced or safety glass window.

H. Doors shall be a minimum of 24 wide and 60 high, unless noted otherwise. Door(s) at eachfan section shall be sufficient to allow motor replacement.

2.10 INTERIOR WALL PANEL CONSTRUCTION SINGLE WALL

A. Where there is no temperature difference across an interior partition at any season, wherelow differential pressures exist still meeting leakage criteria and where shown on thedrawings, panels may be single wall.

B. Wall panels shall be bright ASTM A90 and A653 G60, 22 gauge galvanized steel and shallremain unpainted.

C. Panel corners shall be caulked with sealant.



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D. Panels shall form a water and airtight seal with adjacent panels. Fasteners used to attachthe panel shall not penetrate into the air tunnel.

2.11 INTERIOR WALL PANEL CONSTRUCTION DOUBLE WALL

A. Where there is a temperature difference across an interior partition, where large differentialpressures exist (such as across fan sections) and where shown on the drawings, panelsshall be double wall.

B. Liners shall be bright ASTM A90 and A653 G60, 22 gauge galvanized steel and shallremain unpainted.

C. Interior wall panels shall be the same thickness and insulated with the same insulation asspecified for exterior wall panels.

D. Internal walls shall be completely sealed with EPDM foam gasket to the exterior wall or airtunnel pressure barrier surface.

2.12 INTERNAL COMPONENTS [Note to AE: AE shall edit, adding details for internalcomponents as required.]

A. Motors

1. Provided and installed by unit manufacturer. [See Section 26 60 00 Common MotorRequirements for requirements.]

2. Provided permanent frame & hoist assembly for replacement of motor. Each Motor inexcess of 10 hp shall include a permanently mounted frame integral structure and hoistassembly to allow removal of existing motor and replace with new motor withoutremoval of any unit panel or roof section. Fan section access door shall be sized toallow mechanical assist for motor exchange. Hoist shall be sized and operable inaccordance with Maximum motor frame size.

B. Internal Vibration Isolation:

1. Provided and installed by unit manufacturer.

2. [Note to AE: See also Section 23 73 23 - Custom AHU Fans, for Factory and Fieldbalance requirements. Do not submit until resolution is obtained from the Engineer ifthis Section is absent or specific requirements are not provided.]

C. Hydronic Piping and Valves

1. Provided and installed by unit manufacturer where designated on drawings. Seedrawings for division of work between contractor and manufacturer. See relatedSpecifications for requirements.

D. Air Coils:

1. [See Section 23 82 16 Heating and Cooling Coils for requirements.]

2. Provide drain pan and drain connection for all cooling coils. Drain pan shall be 20gauge stainless steel (min. 304L). Install drain pans under each cooling coil per

ASHRAE 62. [Note to AE: Ensure drain pan design takes into consideration adequatepitch for draining (1/8 per foot).] Pipe drain pans individually to floor drain.

3. Coil Headers and their connections shall allow full drainage back through the respectiveheader connections.

4. Coordinate with Section 23 82 16and with drawings to provide Vents and Drains foreach coil to allow quick and complete draining of respective coil.

5. Structure shall be arranged such that any individual coil may be removed through theface of the coil support structure without affecting the other coils or cutting/removal ofhousing panels.



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6. Field level unit to ensure all coils are level as measured at each coil casing or framingso as to enable full draining by gravity of coil circuitry.

7. Except those drain pans integral with the floor and associated insulation of floor,Manufacturer shall insulate the underside of all drain pans with a minimum of cellular flexible elastomeric foam sheet (Type E).

E. Fans:

[Note to AE: Fan Specification, typically Section 23 34 16, must address dynamicbalancing. Imbalance limits shall not exceed University Standards which require specific

factory balancing of 0.150 in/sec or less 3 planes filter out and a slightly more stringentfinal field balancing of 0.0785 in/sec 3 planes filter out.]

[Note to AE: Special applications desiring to use FAN Arrays (Fan arrays usuallyinclude VFDs) must be fully predesigned in accordance with the Owner for the project

parameters. Manufacturer assistance and pre-engineering is required to be accepted bythe Owner before finalizing Project specific specifications. Fan Arrays shall not be solesourced.]

1. [See Section 23 34 16 for additional requirements.]

F. Filters:

1. Provided and installed by unit manufacturer. [Note to AE: Include a referenced Section23 40 00 HVAC Air Cleaning Devices or include requirements here.]

2. Install differential pressure gauge at each filter bank viewable on the exterior of the unit.

3. Building purge (per LEED 2009 EQ C3.2) will occur following construction and prior tooccupancy. Building purge shall be performed with minimum Type D and minimum typeH filters.

4. Following building purge, provide LEED compliant filter sets [as per Section 23 40 00and Schedule, typically Type D and H filters.]

G. Control Dampers and Actuators:

1. Control dampers and actuators internal to the unit shall be provided and installed by unitmanufacturer. [See Sections 23 09 13.43 - Control Dampers, 23 09 13 - Instrumentation

and Control Devices, and 23 33 00 Air Duct Accessories for requirements.]2. Dampers shall be installed to allow the mounting and future maintenance of damper

actuators. One direct coupled actuator shall be used per damper section. Refer to theDamper Specification for additional criteria. The more restrictive criteria shall prevailshould any conflict(s) arise with other Specifications. Jack shafting is not acceptable.

3. Coordinate with TC for integrating all points real and virtual with BAS.

4. Local control for Energy Recovery components / systems shall be Factory provided(installed and calibrated) and shall be compliant with Project BAS. All points shall bemade available via non-proprietary communication (BACnet etc.) to the BAS Contractorfor trending purposes.

5. [Note to AE: Add a requirement to coordinate with BAS Contractor for integrating allpoints real and virtual with BAS.]

H. Electrical Power:

1. Internal power distribution, lighting, and associated wiring in conduit devices shall befactory provided and installed. Project power and field conduit wiring and connectionswith single point connection on exterior of casing shall be provided and properly air andwater leak proof by the Contractor.



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I. Energy Recovery Wheel(s) General:

1. Provide documentation including, but not limited to, Credentials, Certifications, testingprocedures and templates, etc., for items in this section to the AE and Owner for bothpre-approval as being able to bid and include as part of the subsequent shop drawingdocumentation process.

2. The Contractor responsible for this Specification shall coordinate all requirements withthe Acceptable Manufacturer ensuring all necessary controls, programming, interfacingrelated to their components / System to be provided and fully interconnected to andproperly functioning with the BAS for the Project. The Manufacturer shall clearly define

what products and work the Contractor must seek from the other Trades to fulfill theProject Intent.

3. Energy Recovery Wheel(s) ERW Acceptable Manufacturers / Assembly Providers: Allshall provide certifications and meet or exceed Project criteria and intent.

a. Equipment type in parentheses ( ) indicates only those specific components.

b. General Listing does not automatically pre-approve / approve components.

1) SEMCO Inc.

(a) no exclusions or limitations,

(b) This Manufacturer has successfully met this requirement on previous Projectsbut shall continue to provide Certified Independent LAB credentials and

certified testing from same for any claims of 3 angstrom applications to AEand Owner prior to bids for preview.

2) Thermotech Enterprises Inc.

(a) Limited to Office applications and (Energy Recovery Wheel section(s): 4Angstrom Total Enthalpy; Sensible only, related control)

(b) This Manufacturer shall provide Certified Independent LAB credentials andcertified testing from same for any claims of 3 angstrom applications to AEand Owner prior to bids for preview and consideration to be allowed to bid.

3) Seibu Giken-US

(a) (Ion-Exchange Resin) (Energy Recovery Wheel section(s): 4 Angstrom TotalEnthalpy; Sensible only, related control)

(b) This Manufacturer shall provide Certified Independent LAB credentials andcertified testing from same for any claims of (Ion-Exchange Resin) 3 angstromapplications to AE and Owner prior to bids for preview and consideration to beallowed to bid.

4) DESSICANT ROTORS INTERNATIONAL (driamerica)

(a) (Energy Recovery Wheel section(s): 4 Angstrom Total Enthalpy; Sensibleonly, related control).

(b) This Manufacturer shall provide Certified Independent LAB credentials andcertified testing from same for any claims of 3 angstrom applications to AEand Owner prior to bids for preview and consideration to be allowed to bid.

4. Sensible Only Wheel (When Scheduled):

a. The rotor media shall be made of aluminum that is coated to prohibit corrosion. Themedia shall have a flame spread of less than 25 and a smoke developed of less than50 when rated in accordance with ASTM E-87. Cleaning, purge sector, seals, rotorhousing/support and drive system shall be the same as the Enthalpy Wheel.



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b. Acceptable Manufacturers, construction and quality with regard to the specificsensible only intent shall be the same as listed for the Total Enthalpy EnergyRecovery Wheel Manufacturers: All must provide certifications and meet or exceedProject criteria and intent.

c. Media Cleaning: The media shall be cleanable with low pressure steam (less than 5psi), hot water or light detergent, without degrading the latent recovery. Dry particlesup to 800 microns shall freely pass through the media. Enthalpy wheel shall be self-cleaning by two counter flow air streams.

5. Total Enthalpy Energy Recovery Wheel(s) and assembly:

a. [As a part of the shop drawing, provide documentation for items in this section to theOwner]:

b. Certification that wheel shall provide both sensible and latent heat recovery with atleast 50% of the total as latent recovery and be designed to ensure laminar flow.

c. Verification in writing from the desiccant manufacturer confirming that the internalpore diameter distribution inherent in the molecular sieve desiccant being providedlimits absorption to materials having a kinetic diameter of 4 angstrom or less for thenon-lab application and be specifically developed for the selective transfer of watervapor. All media surfaces shall be coated with a non-migrating solid absorbent layerprior to being formed into the honeycomb media structure.

1) Acknowledge that surfaces sprayed, dip coated, or desiccants that must be

reapplied over time are not acceptable. Silica gel, oxidized aluminum, and othernon-molecular desiccants are not acceptable. Impregnated desiccants in non-metallic substrates such as paper, plastic, synthetic or glass fiber are notacceptable.

d. Confirm the media shall be cleanable with low temperature steam, hot water or lightdetergent, without degrading the latent recovery.

e. Confirm each wheel face, and all desiccant surfaces shall exhibit effectiveantimicrobial action on and within the transfer media to protect against the spread ofmost microbial contaminants. Provide the name of antimicrobial agent being usedwith each Submittal for approval.

f. Confirm enthalpy wheel cassette shall be complete with face seal and perimeter sealto prevent cross leakage between the two air streams. Both/all seals shall be non-

wearable to minimize leakage from occurring at the seal(s).

g. Certify that equal sensible and latent efficiency tests were conducted in accordancewith ASHRAE 84-78P and with results submitted in accordance with ARI 1060standards.

h. Provide an independent wheel test from a credible test laboratory that shalldocument that the desiccant material utilized does not transfer pollutantsencountered in the indoor air environment.

i. The performance certification reports shall be provided as part of the shop drawingsubmittal. No claims regarding (4 angstrom for non-lab and 3 angstrom for Lab)performance will be considered without the required independent test datasupporting such claims.

j. All materials within the airstream shall have a flame spread index of not more than25 and a smoke-developed index of not more than 50 when tested in accordancewith ASTM 384 or UL 723.

k. Provide an independent test report documenting the ability of the wheel faces andtransfer media to actively limit microbial growth.



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l. Casing: Rotor casing shall be provided with structural framework that limits thedeflection of the rotor due to air pressure differential to less than 1/32 inch. Framingshall be galvanized or finished with a corrosion resistant paint. Casing shall begalvanized steel with an epoxy coating for non-lab and lab applications. Supportrotor from two pillow block bearings which can be maintained or replaced withoutremoval of the rotor from its casing or the media from its spoke system. A clutchbearing and extended shaft shall ensure that the wheel can only rotate in the properdirection for effective purging. [Note to AE in regard to special warranty: See Part 1of this Section for the warranty required for bearings.]

m. Frame: The rotor frame shall be industrial spoke system made of aluminum / (epoxycoated aluminum for Lab applications) providing the structural integrity required atdesign pressure differentials. Recovery wheels larger than 12 feet that require fieldassembly shall require that assembly be completed by trained factory servicepersonnel that are employed by the manufacturer of the transfer media. Assemblyby employees of the contractor or other fabricators/assemblers causing or riskcausing voiding or reducing warranty or Media Manufacturers performance will notbe acceptable.

n. Rotor Seals - The rotor shall be supplied with labyrinth seals only, which at no timeshall make contact with any rotating surface of the exchanger rotor face. Thesemulti-pass seals shall utilize (4) four labyrinth stages for optimum performance.

o. Rotor Support System - The rotor media shall be provided in segmented fashion toallow for field erection or replacement of one section at a time without requiring side

access. The media shall be rigidly held in place by a structural spoke system madeof extruded aluminum.

p. Drive: Rotor shall be driven from belt system and electric motor. Wheel shall beperimeter driven with speed reduction by pulley adjustment. Rotor belt shall have noneed for a take-up pulley and no field adjustments required (0% stretch after initialtension). Provide motor with internal overload protection.

q. Inline Gear-Reduction Motor Shall include hardened steel, ground Helical gearingfor quiet operation and shock load resistance. The motor bearings shall be premiumball type. Lubricant shall be high-grade synthetic grease without necessity ofexpansion bladder. Shaft seals shall be quality NBR rubber, spring set lip type.Housing seals shall be machine slip fit O ring type. Housing shall be die castaluminum, coated with electro coat process for harsh environment resistance.

r. Purge Sector: The unit shall be provided with a factory set, field adjustable purgesector designed to limit cross contamination to less than .04 percent of that of theexhaust air stream concentration when operated under appropriate conditions.

s. Wheel Speed Control- Variable speed control of the Enthalpy wheel for capacity andfor frost control and shall be accomplished by the use of an A/C inverter. Theinverter shall include all digital programming with a manual speed adjustment on thefront of the inverter. The drive system shall allow for a turndown ratio of 80:1 (20rpm to 1/4 rpm). Control of the inverter shall be as described in the sequence ofoperation.

t. Wheel Variable Frequency Drive - The drive shall provide low motor noise and highstarting torque. The inverter shall be rated for constant torque applications, withcurrent overload rating of 150% for 60 seconds. Acceptable Manufacturers: [See

Section 26 29 23 Variable Frequency Motor Controllers.]1) Display and Program Features - The digital operator shall provide a minimum 4-

digit LED status display with a built-in analog speed potentiometer, as well asdigital programming for up to 200 parameters. Up to (5) five standard multi-function inputs shall be programmed to allow for preset speeds. The drive shall



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also have an analog input, a multi-function output, two multi-function opencollector outputs, and an analog output as standard.

2) Integral Software The drive shall have on-board software that enables upload,download, and monitoring of parameters. Software on board shall reconfiguredrive defaults, establish presets and eliminate peripheral controls.

3) Communications - A RS-485 serial communication port shall be integral with 32nodes on a single network, interface option boards enable the drive tocommunicate with campus networks. The acceptable protocols are: Apogee P2and BACnet MS\TP.

4) Enclosure - The inverter shall be provided in a NEMA 1 enclosure from 1/8 to 10HP at 230 VAC and 1/2 to 10 HP at 460 VAC. The unit shall maintain acceptableenvironment conditions for the operation of the drive.

u. A combined rotation counter rotation detector module shall be provided tosimultaneously confirm that (1) the recovery wheel is rotating and that (2) it isrotating in the correct direction, allowing for effective purge operation. Magneticproximity sensors shall be provided that detect motion at the outer rim of therecovery wheel and are field wired back to the EM panel.

v. Factory provided pressure tubing and probes shall be factory installed (unlessassembly is direct shipped to the site for field installation) in accordance with factoryrecommendations, and connected to the pressure transducers located within the EMpanel.

w. Factory programming of the DDC control panel shall allow and provide for thefollowing:

1) Conversion of temperature and relative humidity readings into grains, dew pointand enthalpy

2) Conversion of pressure readings across the wheel into supply and return airflowestimates

3) Calculation and reporting of real time unit effectiveness

4) Calculation and reporting of accumulation of energy (BTUs) recovered over time

5) With user input of energy costs, calculation and accumulation of dollars savedover time

6) Startup mode to monitor system pressures and calculate an initial purge anglesetting

7) Automatic wheel speed adjustment to ensure effective purge operation (


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the EM shall be provided by a Factory Employed Service Technician in conjunctionwith the wheel/system startup/commissioning.

y. Field acceptance shall depend on successful field test results meeting designintent/conditions after field installation but prior to Occupancy from an independentwheel/assembly test from an independent test laboratory/Agency and shall providedocumented results that the desiccant material utilized does not transfer pollutantsencountered in the indoor air environment beyond this projects limits and meeting orexceeding the scheduled capacities and energy recovery effectiveness values testedin accordance with ASHRAE 84 and ARI Standard 1061 at design and part load

conditions. Products with ratings/field results that fail field testing will not beaccepted. Contractor shall be responsible making necessary corrections/replacements.

6. Temperature Control Panel - Variable speed control shall be accomplished by the useof an A/C inverter. The inverter shall include all digital programming with a manualspeed adjustment on the front of the inverter. The drive system shall allow for aturndown ratio of 80:1 (20 rpm to 1/4 rpm). The control system shall include fourlinearized thermistor (If wheel manufacturer provides controls) or four 1000 ohmplatinum RTD (If Building Automation Systems (BAS) Contractor provides controls) asfollows:

a. Proportional temperature controller mounted in the supply air stream.

b. Differential summer/winter changeover sensors mounted in the outdoor and return

airstreams.c. Frost prevention sensor located in the exhaust air stream.

d. Digital readout of the temperature readings recorded by these sensors and controlset points is displayed by the control panel.

7. Digital Performance Display Module - In addition to the above Temperature ControlPanel and four linearized thermistor sensors, the following sensors are required formonitoring, trending and control: temperature and humidity sensors location in theoutside, supply, and return air streams. A temperature sensor only shall be located inthe exhaust air stream. Airflow sensors shall be located in the supply and exhaust airstreams. All of the listed sensors shall have digital capabilities to send readable signalsto the control panel and also be interfaced with the BAS. Provide all naming andmapping of sensors, their inputs and outputs to the BAS Contractor. Variable speed

control shall be accomplished by the use of an A/C inverter. The inverter shall includedigital programming with manual speed adjustment on the front of the inverter. Theinverter shall allow for a turndown ratio of 80:1 (20 rpm to rpm). Refer to relatedSpecifications for instrumentation requirements.

8. Media Cleaning:

a. The media shall be cleanable with low pressure steam (less than 5 psi), hot water orlight detergent, without degrading the latent recovery. Dry particles up to 800microns shall freely pass through the media. Enthalpy wheel shall be self-cleaningby two counter flow air streams.

J. BAS Contractor Controls / Coordination:

1. This Contractor shall coordinate with BAS Contractor, who shall provide all necessaryand remaining controls not provided by Unit Manufacturer and interconnect BAS withUnit controller(s) and VFD(s), coordinating all control, monitoring or trend points andcalculated values available from the Unit(s), Units controller(s) and VFD(s) and providefor remote trending/control and functions described in the BAS specifications.

a. Provided and installed by the BAS Contractor in the field.



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K. Provide drain pan and drain connection for all cooling coils. Fabricate drain pan from 20gauge stainless steel. Install a drain pan under each cooling coil per ASHRAE 62. Extenddrain pans the entire width of each coil, including piping and header if in the air stream, andfrom the upstream face of each coil to a distance 1/2 of the vertical coil height downstreamfrom the downstream face. Pitch the drain pans in two directions towards the outlet, with aslope of at least 1/8 per foot. Pipe the drain pans individually to floor drain.

L. Manufacturer shall insulate the underside of all drain pans, except those integral with thefloor, with a minimum of 3/4 cellular flexible elastomeric foam sheet (Type E).

PART 3 - EXECUTION

3.1 FACTORY REPRESENTATION

A. The manufacturer shall provide a qualified representative at the project site during rigging,hoisting and installation of unit. Representative shall ensure proper installation and sectionconnection methods are employed.

B. [Note to AE: When / if Project is in an existing building. New units must be installedthrough areaways and existing door and/or window openings. Require appropriate Factorytesting, disassembly of unit prior to shipment. Coordinate component sizes with Contractor

prior to shipment.]

C. Manufacturer shall ensure that seals have been applied around all Factory installed piping

and conduit penetrations. Penetrations shall be air tight meeting leakage criteria.

D. Manufacturer shall inspect unit installation and assist in start-up and dynamic balancing ofunit. Manufacturers start-up engineer shall assist in commissioning of all unit functionsand submit report containing all data recorded and a certification that the unit is operatingproperly.

3.2 CONTRACTOR SHALL:

A. Allow space to receive work and opening dimensions are as indicated on shop drawingsand illustrated by the manufacturer.

B. Provide proper power supply.

C. Field assemble all units per manufacturers instructions/supervision. Coordinate withmanufacturer.

D. Support unit from building structure as indicated on the drawings. Coordinate all work withthe General Contractor prior to installation.

E. Locate ducts with sufficient space around equipment for normal operation andmaintenance/replacement in accordance with the Project documents, SMACNA. And

ASHRAE.

F. Install all additional reinforcing, columns and beams as detailed by the manufacturer.

G. Provide properly finished openings in panels for thermometers and controllers. Providepitot tube openings for testing systems. Seal all openings and around all appurtenanceswith proper SMACNA closures conforming to pressure class of the housing prior tocleaning.

H. During construction provide temporary closures of metal or taped polyethylene over

openings into housing ducts to prevent dust from entering ductwork.

I. Seal all contractor installed penetrations airtight. Seal all openings prior to cleaning. Sealholes with proper SMACNA closures conforming to pressure class of the housing prior tocleaning.



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J. Complete all (pre-startup) Commissioning Requirements in accordance with relatedSections.

K. Complete all Startup Commissioning Requirements in accordance with related Sections.

L. Coordinate with TC and TAB to complete all debugging prior to Witnessing by Owner ofFunctional Testing.

M. Perform Using Agency training as required.

N. Install clean filters in unit just prior to Owner Witnessing of Functional Testing.

3.3 TESTING OF EACH UNIT/SYSTEMA. Quality Assurance

1. Failure to pass (in part or whole) quality assurance verification/testing in the presenceof the AE and/or Owner may incur prompt remedies at no additional cost to theProject or Owner.

B. Manufacturer and/or Contractor Conducted Field Testing:

1. Housing Leak Testing:

a. Once unit is installed and the fans are operational, test housing for leakage.

b. Test housing at pressures specified under Leakage Rate/Pressure Rating in Part 2of this specification.

c. Perform air flow measurements in compliance with ASHRAE/ANSI standard 111.

C. Energy Recovery Section(s) Testing:

1. Factory Startup and Field Commissioning - After the units are installed, a final factorycheckout and startup will be completed to ensure proper purge adjustment, sealadjustment, control settings and other key operational functions. This service shall becompleted by trained factory service personnel that are employed by the manufacturerof the transfer media. Final commissioning by employees of the contractor or wheelcasing fabricators that purchase the transfer media from others will not be acceptable.

2. Once the final factory checkout is completed, and before final occupancy, wheelinstallation will be commissioned using a SF-6 Tracer Gas Testing Procedure similarto that outlined by ASHRAE Standard 84. This testing must be performed by anexperienced Qualified Factory Approved Independent Contractor (at no additional cost

to the Project or Owner) to determine quantitative verification of the following:

a. Cross contamination of exhaust air contaminates to the outdoor air stream due tothe energy recovery wheel media, seals, and purge, is below .045% limit.

b. If Cross-Contamination of exhaust air contaminants to the outdoor air streamexists due to leakage within the energy recovery systems housing.

c. If Cross-Contamination of exhaust air contaminants to the outdoor air stream existdue to entrainment of air exhausted from the facility to the outdoor air intakehood.

D. Final Contaminant Carry-over TVOC Commissioning After Occupancy

1. To confirm that the recovery wheel is functioning at the factory specified limit for cross-contamination, air samples will be collected from the outdoor, supply and the return air

streams around the total energy wheel on adsorbent filled adsorption tubes during an8 hour time period while the facility is operated at full occupancy and activity. Thesetubes will be analyzed using a high end mass spectrometer by an experienced andrecognized independent research laboratory. A report documenting the total volatileorganic compound spectrum and total concentration associated with each air stream



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will be presented in a final report to confirm that any cross-contamination is within thefactory specifications.

E. Document and Provide all field testing (and via System BAS) of units including but notlimited to:

1. Performance Total and Sensible capacities,

a. Sensible and latent efficiency tests in accordance with ASHRAE 84-78P and withresults submitted in accordance with ARI 1060 standards.

b. All Data specified per above temperature and humidity levels at each air stream

around the recovery wheel. Temperature and relative humidity readings alsoprovide related grains, dew point and enthalpy

c. Conversion of pressure readings across the wheel into supply and return airflowestimates

d. (Calculation and reporting of) real time unit effectiveness

e. (Calculation and reporting of) accumulation of energy (BTUs) recovered over time

f. With user input of energy costs, (calculation and accumulation of) dollars savedover time

g. Startup mode to monitor system pressures and calculate an initial purge anglesetting

h. Automatic wheel speed adjustment to ensure effective purge operation (


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END OF SECTION

This section of the U of I Facilities Standards establishes minimum requirements only.It should not be used as a complete specification.



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Custom AHU

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