Addendum 2 2026-081.pdf

Invitation for Bid No. 2026-081

Judicial Center Cooling Tower Project

ADDENDUM No. 2

ISSUE DATE: September 18, 2026

Responding Offerors on this project are hereby notified that this Addendum shall be made a part of the above named IFB document.

The following items add to, modify, and/or clarify the IFB documents and shall have the full force and effect of the original Documents. This Addendum shall be acknowledged by the Offeror in the IFB document.

An additional site visit will be at 10:00 AM on Wednesday, September 23, 2026, at 400 N. Main

Street, Monroe, NC for anyone who would like to attend.

Union County, North Carolina Addendum No. 2 IFB 2026-081 Judicial Center Cooling Tower Project

For equipment substitutions, please refer to Section 3.3, Substitutions of the A701 Instructions.

Bidders must submit a specific product with supporting information through Procurement by the reopened question deadline.

New specifications sections for the Hydronic Pump and the Cooling tower.

Question/Answer Section

1. Question: Which controls contractor is currently monitoring the building for Union County and what is their contact info?

Answer: Union County Facilities Monitors their equipment.

2. Question: Which chemical treatment provider is currently providing chemical treatment service for the Judicial Center and what is their contact info?

Answer: Green Way Chemicals.

3. Question: We anticipate this work to commence toward the end of the year after the cooling tower is procured. Because of anticipated low demand for cooling during the winter months, will temporary conditioning be required by the Owner during the shutdown period needed to remove/replace the equipment?

Answer: Temporary cooling will not be required as the other cooling tower on the system can handle the cooling load during the off season.

4. Question: No pump or cooling tower product specifications were supplied with the bid documents. The equipment schedule on M101 replaces the existing Evapco cooling tower with a new cooling tower by American Cooling Tower, Inc. and replaces the existing Taco condenser water pump with a new pump by B&G. Are these two pieces of equipment to be provided only as scheduled as basis of design or is there a list of approved equal manufacturers available?

Answer: Approved equals for the cooling tower are:

1. Evapco

2. Baltimore Aircoil Company (BAC)

3. SPX Cooling Technologies (Marley)

4. American Cooling Tower

5. Or Approved Equal.

Approved equals for the pumps are:

1. Bell and Gossett

2. Taco

3. Armstrong Fluid Technology

4. Or Approved Equal.

5. Question: Please confirm whether the cooling tower fan and new pump require VFDs

Answer: Both the new cooling tower fan and the new pump will be required for VFD’s.

6. Question: Please confirm whether the new cooling tower controls are required to tie into the existing building automation system or is this excluded from pricing. If required, please provide incumbent controls contractor.

Answer: The intent is for the new cooling tower controls to be integrated with the existing

Building Automation System (BAS). Trane is our existing/incumbent controls contractor.

7. Question: Please clarify whether any special requirements apply to crane access, street closures, equipment delivery, rigging, site access, security, parking, or staging.

• Answer: Any crane access, equipment delivery, rigging, staging, parking, site access, or security requirements will need to be coordinated with the County prior to performing the work.

The contractor shall be responsible for developing its proposed crane, rigging, delivery, and staging plan based on field conditions and submitting it to the County for review and coordination. Any required street or access closures shall also be coordinated and approved in advance.

8. Question: Please confirm the allowable shutdown time for the cooling tower and condenser-water pump replacement. Please also confirm whether after-hours, weekend work, or temporary cooling is required.

• Answer: Shutdown time restrictions will be coordinated based on the construction schedule. The demolition and installation of the cooling tower shall be performed on a weekend due to pedestrian traffic and safety concerns associated with crane operations, rigging, equipment removal, and installation.

Other after-hours or weekend work is not required or approved at this time but may be discussed and coordinated with the County if needed.

A temporary cooling tower is not required.

9. Question: Please clarify whether chemical cleaning, passivation, initial water treatment, and water testing are required, or if the contractor is only responsible for reconnecting the existing chemical-feed line.

Answer: Contractor is only required for reconnecting the lines.

10. Question: Please confirm whether equivalent cooling tower and pump manufacturers are acceptable. If equivalent manufacturers are acceptable, please identify approved manufacturers.

Answer: Approved equals for the cooling tower are:

1. Evapco

2. Baltimore Aircoil Company (BAC)

3. SPX Cooling Technologies (Marley)

4. American Cooling Tower

5. Or Approved Equal

Approved equals for the pumps are:

1. Bell and Gossett

2. Taco

3. Armstrong Fluid Technology

4. Or Approved Equal

End of Addendum No. 2

SECTION 236500

COOLNG TOWERS

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 SUMMARY

A. This Section includes factory assembled and tested, open circuit mechanical induced-draft vertical discharge cooling tower.

1.3 SUBMITTALS

A. Product Data: For each type of product indicated. Include rated capacities, pressure drop, performance curves with selected points indicated, furnished specialties, and accessories.

B. Shop Drawings: Complete set of manufacturer's prints of equipment assemblies, control panels, sections and elevations, and unit isolation. Include the following:

1. Assembled unit dimensions.

2. Weight and load distribution.

3. Required clearances for maintenance and operation.

4. Sizes and locations of piping and wiring connections.

5. Wiring Diagrams: For power, signal, and control wiring. Differentiate between manufacturer installed and field installed wiring.

6. Submit documentation verifying that the existing supporting structure and framing are adequate to support the new cooling tower, including operating weight, equipment loads, seismic loads, wind loads, vibration, and concentrated loads. Submit manufacturer’s operating weight and load distribution information for review prior to installation.

C. Operation and Maintenance Data: Each unit to include operation and maintenance manual.

1.4 QUALITY ASSURANCE

A. Verification of Performance:

1. The thermal performance shall be certified by the Cooling Technology Institute in accordance with CTI Certification Standard STD-201. Lacking such certification, a field acceptance test shall be conducted within the warranty period in accordance with CTI Acceptance Test Code ATC-105, by a Licensed CTI Thermal Testing Agency.

2. Unit Sound Performance ratings shall be tested according to CTI ATC-128 standard.

Sound ratings shall not exceed specified ratings.

3. Unit shall meet or exceed energy efficiency per ASHRAE 90.1-2019.

1.5 WARRANTY

A. Submit a written warranty executed by the manufacturer, agreeing to repair or replace components of the unit that fail in materials and workmanship within the specified warranty period.

1. Fan Motor/Drive System: Warranty Period shall be Five (5) years from date of unit shipment from Factory (fan motor(s), fan(s), fan shaft(s), bearings, mechanical support, sheaves, bushings and belt(s)).

2. The Entire Unit shall have a comprehensive one (1) year warranty against defects in materials and workmanship from startup, not to exceed eighteen (18) months from shipment of the unit.

PART 2 - PRODUCTS

2.1 MANUFACTURERS

A. Manufacturers: Subject to compliance with requirements, provide cooling towers manufactured by one of the following:

1. EVAPCO Model AT

2. Baltimore Aircoil Company (BAC)

3. SPX Cooling Technologies (Marley)

4. American Cooling Tower

5. Approved Substitute

2.2 THERMAL PERFORMANCE

A. Each unit shall be capable of cooling 900 GPM of water entering at 95° F leaving at 85° F at a design entering wet bulb of 78° F.

2.3 IBC COMPLIANCE

A. The structure of this product shall be designed, analyzed, and constructed in accordance with the wind and seismic load requirements of the following:

2018 IBC, ASCE/SEI 7-05, ASCE/SEI 7-10, ASCE/SEI 7-16, NFPA 5000. For Importance Factor (IP) = 1.0, SDS = .25g, design wind pressure P = 40 psf.

2.4 COMPONENTS

A. Description: Factory assembled and tested, induced draft counter flow cooling tower complete with fan, fill, louvers, accessories and rigging supports

B. Materials of Construction

1. Cooling tower basin shall be fabricated of Type 304 stainless steel.

2. All fasteners, hardware, and components exposed to circulating water or routinely wetted shall be stainless steel.

3. Structural framing and exterior panels shall be galvanized steel unless otherwise indicated.

4. Upper Casing, channels and angle supports shall be constructed of heavy gauge mill hot-dip galvanized steel. Fan cowl and guard shall be constructed of galvanized steel.

All galvanized steel shall be coated with a minimum of 2.35 ounces of zinc per square foot of area (G-235 Hot-Dip Galvanized Steel designation). During fabrication, all galvanized steel panel edges shall be coated with a 95% pure zinc-rich compound.

”All evaporative cooling equipment utilizing galvanized construction require initial passivation to maximize the service life of the equipment. The site's water treatment vendor should be contacted several weeks prior to adding any water to the system to provide a passivation plan along with associated passivation plan costs.

C. Fan(s):

1. Fan(s) shall be high efficiency axial propeller type with aluminum wide chord blade construction. Each fan shall be dynamically balanced and installed in a closely fitted cowl with venturi air inlet for maximum fan efficiency.

D. Drift Eliminators

1. Drift eliminators shall be constructed entirely of Polyvinyl Chloride (PVC) in easily handled sections. Design shall incorporate three changes in air direction and limit the water carryover to a maximum of 0.001% of the recirculating water rate. Drift eliminators shall be self-extinguishing, have a flame spread of less than 25 under ASTM E84, and shall be resistant to rot, decay and biological attack.

E. Water Distribution System

1. Spray nozzles shall be precision molded ABS, large orifice nozzles utilizing fluidic technology for superior water distribution over the fill media. Nozzles shall be designed to minimize water distribution system maintenance. Spray header and branches shall be Schedule 40 Polyvinyl Chloride (PVC) for corrosion resistance with a steel connection to attach external piping.

F. Heat Transfer Media

1. Fill media shall be constructed of Polyvinyl Chloride (PVC) of cross-fluted design and suitable for inlet water temperatures up to 130° F. The bonded block fill shall be bottom supported and suitable as an internal working platform. Fill shall be self-extinguishing, have a flame spread of less than 25 under ASTM E84, and shall be resistant to rot, decay and biological attack.

G. Air Inlet Louvers

1. The air inlet louvers shall be constructed from UV inhibited Polyvinyl Chloride (PVC) and incorporate a framed interlocking design that allows for easy removal of air inlet louvers for access to the entire basin area for maintenance. The air inlet louvers shall have a minimum of two changes in air direction and shall be of a non-planar design to prevent splash-out and block direct sunlight & debris from entering the basin. Air inlet louvers shall be self-extinguishing, have a flame spread of less than 25 under ASTM E84, and shall be resistant to rot, decay and biological attack.

H. Make up Float Valve Assembly

1. Make up float assembly shall be a mechanical brass valve with an adjustable plastic float.

I. Pan Strainer

1. Pan Strainer(s) shall be all Type 304 Stainless Steel construction with large area removable perforated screens.

J. Pipe Connection Type

1. Any connections provided with a Groove (GVD) or Beveled for Welding/Grooved (BFW/GVD) shall conform to standard groove specification (SGS).

2.5 MOTORS AND DRIVES

A. Fan Motor

1. Fan motor(s) shall be totally enclosed, ball bearing type electric motor(s) suitable for moist air service. Motor(s) are Premium Efficient, Class F insulated, 1.15 service factor design. Motor shall be inverter rated per NEMA MG1 Part 31.4.4.2 and suitable for variable torque applications. Fan motor shall be provided with a variable frequency drive (VFD) for fan speed control. Fan motor(s) shall include strip-type space heaters with separate leads brought to the motor conduit box.

2. Variable Frequency Drive: Provide factory or field mounted VFD for each cooling tower fan motor. VFD shall be sized for the motor horsepower and shall be suitable for cooling tower applications. VFD shall provide adjustable fan speed from minimum to maximum operating speed and shall include all required motor protection, overload protection, and control interfaces.

B. Fan Drive

1. The fan drive shall be multigroove, solid back V-belt type with QD tapered bushings designed for 150% of the motor nameplate power. The belt material shall be neoprene reinforced with polyester cord and specifically designed for evaporative equipment service. Fan sheave shall be aluminum alloy construction. Belt adjustment shall be accomplished from the exterior of the unit.

C. Fan Shaft

1. Fan shaft shall be solid, ground and polished steel. Exposed surface shall be coated with rust preventative.

D. Fan Shaft BeaHngs

1. Fan Shaft Bearings shall be heavy-duty, self-aligning ball type bearings with extended lubrication lines to grease fittings located on access door frame. Bearings shall be designed for a minimum L-10 life of 100,000 hours.

2.6 MAINTENANCE ACCESS

A. Fan Section

1. Access door shall be hinged and located in the fan section for fan drive and water distribution system access.

B. Basin Section

1. Framed removable louver panels shall be on all four (4) sides of the unit for pan and sump access.

C. Internal Working Platform

1. Internal working platform shall provide easy access to the fans, belts, motors, sheaves, bearings, all mechanical equipment and complete water distribution system.

The fill shall be an acceptable means of accessing these components.

Copyright 2018 AIA Union County Judicial Center Cooling Tower 12/18

HYDRONIC PUMPS 232123 - 1

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SECTION 232123 - HYDRONIC PUMPS

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 SUMMARY

A. Section Includes:

1. Separately coupled, base-mounted, end-suction centrifugal pumps.

1.3 ACTION SUBMITTALS

A. Product Data: For each type of pump.

1. Include certified performance curves and rated capacities, operating characteristics, furnished specialties, final impeller dimensions, and accessories for each type of product indicated.

2. Indicate pump's operating point on curves.

1.4 CLOSEOUT SUBMITTALS

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

PART 2 - PRODUCTS

2.1 PERFORMANCE REQUIREMENTS

A. 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.

2.2 MANUFACTURERS

A. BASIS OF DESIGN:

1. Bell and Gossett; Series 1510

2. Taco Comfort; FI Series

3. Armstrong Fluid Technology; 4300 Series

4. Or Approved Equal.

HYDRONIC PUMPS 232123 - 2

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2.3 SEPARATELY COUPLED, BASE-MOUNTED, END-SUCTION CENTRIFUGAL PUMPS

A. Source Limitations: Obtain pumps from single source from single manufacturer.

B. Description: Factory-assembled and -tested, centrifugal, overhung-impeller, separately coupled, end-suction pump with flexible shaft coupling as defined in HI 1.1-1.2 and HI 1.3; designed for base mounting, with pump and motor shafts horizontal.

C. Pump Construction:

1. Casing: Radially split, cast iron, with threaded gauge tappings at inlet and outlet, drain plug at bottom and air vent at top of volute, and flanged connections. Provide integral mount on volute to support the casing, and provide attached piping to allow removal and replacement of impeller without disconnecting piping or requiring realignment of pump and motor shaft.

2. Impeller: ASTM B584, cast bronze; statically and dynamically balanced, keyed to shaft, and secured with a locking cap screw. For pumps that are not frequency-drive controlled, trim impeller to match specified performance.

3. Pump Shaft: Carbon steel, with copper-alloy shaft sleeve.

4. Seal, Mechanical Type: Mechanical seal consisting of carbon rotating ring against a ceramic seat held by a stainless steel spring, and NBR bellows and gasket.

5. Pump Bearings: Grease-lubricated ball bearings in cast-iron housing with grease fittings.

D. Shaft Coupling: Molded-rubber insert and interlocking spider capable of absorbing vibration.

Couplings shall be drop-out type to allow disassembly and removal without removing pump shaft or motor.

E. Coupling Guard: Dual rated; ANSI B15.1, Section 8; OSHA 1910.219 approved; steel;

removable; attached to mounting frame.

F. Mounting Frame: Welded-steel frame and cross members, factory fabricated from

ASTM A36/A36M channels and angles. Fabricate to mount pump casing, coupling guard, and motor.

G. Motor: Comply with NEMA designation, temperature rating, service factor, and efficiency requirements for motors. In "Enclosure" Subparagraph below, coordinate type availability with equipment manufacturers.

1. Enclosure: Totally enclosed, fan cooled.

2. NEMA Premium Efficient motors as defined in NEMA MG 1.

3. 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.

4. Controllers, Electrical Devices, and Wiring: Comply with requirements for electrical devices and connections specified in electrical Sections.

5. Variable-speed motor.

6. Variable Frequency Drive: Provide inverter-duty motor suitable for operation with a variable-frequency drive. Furne pump with factory-coordinated VFD.

HYDRONIC PUMPS 232123 - 3

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2.4 PUMP SPECIALTY FITTINGS

A. Suction Diffuser:

1. Angle pattern.

2. 175-psig pressure rating, cast-iron body and end cap, pump-inlet fitting.

3. Bronze 16-mesh wire startup and bronze permanent strainers with 3/16-inch.

4. Bronze straightening vanes.

5. Drain plug.

6. Factory-fabricated support.

B. Triple-Duty Valve:

1. Angle or straight pattern.

2. 175-psig pressure rating, cast-iron body, pump-discharge fitting.

3. Valve with multi-turn stem and memory stop to allow valve to be returned to its original position after shutoff.

4. Brass valve disc with EPDM rubber seat.

5. Type 304 stainless steel valve stem.

6. Drain plug and bronze-fitted shutoff, balancing, and check valve features.

7. Brass gauge ports with integral check valve and orifice for flow measurement.

PART 3 - EXECUTION

3.1 EXAMINATION

A. Examine equipment foundations and anchor-bolt locations for compliance with requirements for installation tolerances and other conditions affecting performance of the Work.

B. Examine roughing-in for piping systems to verify actual locations of piping connections before pump installation.

C. Examine foundations and inertia bases for suitable conditions where pumps will be installed.

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

3.2 PUMP INSTALLATION

A. Install pumps to provide access for periodic maintenance including removing motors, impellers, couplings, and accessories.

B. Independently support pumps and piping so weight of piping is not supported by pumps and impweight of pumps is not supported by piping.

C. Automatic Condensate Pump Units: Install units for collecting condensate and extend to open drain.

D. Equipment Mounting:

HYDRONIC PUMPS 232123 - 4

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1. Install base-mounted pumps on cast-in-place concrete equipment bases. Comply with requirements for equipment bases and foundations specified in Section 033000 "Cast-in-

Place Concrete."

2. Comply with requirements for vibration isolation devices specified in Section 230548.13

"Vibration Controls for HVAC."

E. Equipment Mounting: Install in-line pumps with continuous-thread hanger rods and spring hangers of size required to support weight of in-line pumps.

1. Comply with requirements for hangers and supports specified in Section 230529

"Hangers and Supports for HVAC Piping and Equipment."

3.3 ALIGNMENT

A. Perform alignment service. When required by manufacturer to maintain warranty coverage, engage a factory-authorized service representative to perform it.

B. Comply with pump and coupling manufacturers' written instructions.

C. After alignment is correct, tighten foundation bolts evenly but not too firmly. Completely fill baseplate with nonshrink, nonmetallic grout while metal blocks and shims or wedges are in place. After grout has cured, fully tighten foundation bolts.

3.4 PIPING CONNECTIONS

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

B. Connect piping to pumps. Install valves that are same size as piping connected to pumps.

C. Install suction and discharge pipe sizes equal to or greater than diameter of pump nozzles.

D. Install check, shutoff, and throttling valves or triple-duty valve on discharge side of pumps.

E. Install suction diffuser and shutoff valve on suction side of pumps.

1. Use startup strainer for initial system startup. Install permanent strainer element before turnover of system to Owner.

F. Install flexible connectors on suction and discharge sides of base-mounted pumps between pump casing and valves.

G. Install pressure gauges on pump suction and discharge or at integral pressure-gauge tapping, or install single gauge with multiple-input selector valve.

H. Install check valve on each condensate pump unit discharge unless unit has a factory-installed check valve.

3.5 STARTUP SERVICE

A. Perform startup service.

HYDRONIC PUMPS 232123 - 5

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1. Complete installation and startup checks in accordance with manufacturer's written instructions.

2. Check piping connections for tightness.

3. Clean strainers on suction piping. Use startup strainer for initial startup.

4. Perform the following startup checks for each pump before starting:

a. Verify bearing lubrication.

b. Verify that pump is free to rotate by hand and that pump for handling hot liquid is free to rotate with pump hot and cold. If pump is bound or drags, do not operate until cause of trouble is determined and corrected.

c. Verify that pump is rotating in correct direction.

5. Prime pump by opening suction valves and closing drains, and prepare pump for operation.

6. Start motor.

7. Open discharge valve slowly.

3.6 FIELD QUALITY CONTROL

A. Perform tests and inspections.

B. Hydronic pumps will be considered defective if they do not pass tests and inspections.

C. Prepare test and inspection reports.

END OF SECTION 232123