Section 236500
Cooling Towers
	PART 1 GENERAL
1.01	SECTION INCLUDES
A.	Closed circuit, forced draft, counterflow cooling towers.
1.02	REFERENCE STANDARDS
A.	ASHRAE 90.1-2019 – Energy Standard for Buildings Except Low-Rise Residential Buildings.
B.	ASME B31.5 - Refrigeration Piping and Heat Transfer Components 2016.
C.	ASME Section VIII Boiler and Pressure Vessel Code.
D.	ASTM A123/A123M - Standard Specification for Zinc (Hot-Dip Galvanized) Coatings on Iron and Steel Products 2017.
E.	ASTM A653/A653M - Standard Specification for Steel Sheet, Zinc-Coated (Galvanized) or Zinc-Iron Alloy-Coated (Galvannealed) by the Hot-Dip Process 2018.
F.	ASTM B117 - Standard Practice for Operating Salt Spray (Fog) Apparatus 2018.
G.	ASTM E84 - Standard Test Method for Surface Burning Characteristics of Building Materials 2018b.
H.	ASTM D2794 - Standard Test Method for Resistance of Organic Coatings to the Effects of Rapid Deformation (Impact).
I.	ABMA STD 9 - Load Ratings and Fatigue Life for Ball Bearings 2015.
J.	ABMA STD 11 - Load Ratings and Fatigue Life for Roller Bearings 2014.
K.	CTI STD-201 OM - Operations Manual for Thermal Performance Certification of Evaporative Heat Rejection Equipment 2017.
L.	CTI STD-201 RS - Performance Rating of Evaporative Heat Rejection Equipment 2017.
M.	ISO 9001 - Quality management systems -- Requirements 2015.
N.	NEMA MG 1 - Motors and Generators 2017.
O.	ASCE/SEI 7 - Minimum Design Loads and Associated Criteria for Buildings and Other Structures.
1.03	SUBMITTALS
A.	Product Data: Provide rated capacities, dimensions, weights and point loadings, accessories, electrical requirements and wiring diagrams, and location and size of field connections. 
B.	Shop Drawings: Indicate suggested structural steel supports including dimensions, sizes, and locations for mounting bolt holes.
C.	Manufacturer's Certificate: Certify that cooling tower performance, based on CTI STD-201 meets or exceeds specified requirements and submit performance curve plotting leaving water temperature against wet bulb temperature.
D.	Manufacturer's Instructions: Submit manufacturer's complete installation instructions.
E.	Operation and Maintenance Data: Include start-up instructions, maintenance data, parts lists, controls, and accessories.
F.	Warranty: Submit manufacturer's warranty and ensure forms have been filled out in Owner's name and registered with manufacturer.
1.04	QUALITY ASSURANCE
A.	Manufacturer Qualifications:  Company specializing in manufacturing the type of products specified in this section, with minimum 20 years of documented experience and ISO 9001 certification.  
B.	Installer Qualifications: Company specializing in performing the type of work specified in this section with minimum 20 years of experience and approved by manufacturer.
C.	Product Performance: 
1.	Cooling tower must have a minimum energy rating of [_____] per ASHRAE 90.1, 189 and CA Title 24.
1.05	DELIVERY, STORAGE, AND HANDLING
A.	Equipment will be factory-assembled, including cold water basin, heat transfer section, water distribution, fan drive system, and casing panels. For shipping, disassemble into as large as practical sub-assemblies so that minimum amount of field work is required for re-assembly. 
B.	Comply with manufacturer's installation instructions for rigging, unloading, and transporting units.
1.06	WARRANTY
A.	One-year warranty after start-up, or eighteen months from date of shipment, whichever occurs first. Warranty to include coverage for defects in material and workmanship.
B.	Fans, fan shafts, bearings, sheaves, gearboxes, drive shafts, couplings, and mechanical equipment support must be warranted against defects in materials and workmanship for a period of five (5) years; or seven (7) if motor space heater is properly wired.
	PART 2 PRODUCTS
2.01	MANUFACTURERS
A.	Closed Circuit, Induced Draft, Crossflow Cooling Towers:
1.	Basis of Design: Baltimore Aircoil Company; VF1 or VFL: www.baltimoreaircoil.com #BAC
2.02	MANUFACTURED UNITS
A.	Provide units for indoor or outdoor use, factory-assembled, vertical discharge, forced blow through design, with fan assemblies built into or beside casing.
2.03	COMPONENTS
A.	Cold Water Basin:
1.	Heavy-gage G-235 (Z700) galvanized steel with all edges given a protective coating of zinc-rich compound. Basin will include large area lift out strainers with perforated openings sized smaller than the water distribution system nozzles and an anti-votexing device to prevent air entrainment. The strainer and anti-vortexing device will be constructed of the same material as the basin to prevent dissimilar metal corrosion. Provide drain/clean-out connection.
----- Alternate for 304 Stainless Steel -----
2.	Heavy-gage 304 stainless steel with all edges given a protective coating of zinc-rich compound. Basin will include large area lift out strainers with perforated openings sized smaller than the water distribution system nozzles and an anti-votexing device to prevent air entrainment. The strainer and anti-vortexing device will be constructed of the same material as the basin to prevent dissimilar metal corrosion. Provide drain/clean-out connection. Basins constructed of 301 stainless steel are not acceptable.
----- Alternate for 316 Stainless Steel -----
3.	Heavy-gage 316 stainless steel with all edges given a protective coating of zinc-rich compound. Basin will include large area lift out strainers with perforated openings sized smaller than the water distribution system nozzles and an anti-votexing device to prevent air entrainment. The strainer and anti-vortexing device will be constructed of the same material as the basin to prevent dissimilar metal corrosion. Provide drain/clean-out connection. Basins constructed of 301 or 304 stainless steel are not acceptable.
B.	Casing Panels and Framework:
----- Thermosetting Hybrid Polymer Coated Steel-----
1.	Casing panels: Galvanized steel protected by a thermosetting hybrid polymer. The polymer to consist of G-235 (Z700 metric) hot-dip galvanized steel prepared in a four-step (clean, pre-treat, rinse, and dry) process with an electrostatically applied, thermosetting, hybrid polymer fuse-bonded to the substrate during a thermally activated curing stage and monitored by a 23-step quality assurance program. Other coatings must be submitted to the engineer for pre-approval. Approved equals must have undergone testing, resulting in the following results as a minimum:
a.	When X-scribed to the steel substrate, unit to withstand 6000 hours of 5 percent salt spray per ASTM B117 without blistering, chipping, or loss of adhesion.
b.	When X-scribed to the steel substrate, unit to withstand 6000 hours of exposure to acidic (pH=4.0) and alkaline (pH=11.0) water solutions at 95 degrees F (35 degrees C) without signs of chemical attack.
c.	Unit to withstand impact of 160 in-lbs per ASTM D2794 without fracture or delamination of the polymer layer.
d.	Unit to withstand 6000 hours of ultraviolet radiation equivalent to 120,000 hours of noontime sun exposure without loss of functional properties.
e.	Unit to withstand 200 thermal shock cycles between minus 25 degrees F and 180 degrees F (minus 32 degrees C and 82 degrees C) without loss of adhesion or other deterioration.
f.	Unit to withstand 6000 hours of exposure to 60 psi (42,184 kg/m^2) water jet without signs of wear or erosion.
g.	Type 304 stainless steel may be supplied as an equal to eliminate the need for passivation, minimize maintenance requirements, and prolong equipment life.
----- ALTERNATE for Galvanized Steel -----
2.	Casing panels and framework will be constructed of G235 galvanized steel. Panels will utilize double-brake flanges for maximum strength and rigidity and reliable sealing of watertight joints. The fill will be removable from the basin section to facilitate shipping and handling. The fan(s) and fan drive system, including the fan motor, will be factory mounted and aligned and located in the dry entering airstream to ensure reliable operation and ease of maintenance.
----- ALTERNATE for 304 Stainless Steel -----
3.	Casing panels and framework will be constructed of 304 stainless steel. Panels will utilize double-brake flanges for maximum strength and rigidity and reliable sealing of watertight joints. The fill will be removable from the basin section to facilitate shipping and handling. The fan(s) and fan drive system, including the fan motor, will be factory mounted and aligned and located in the dry entering airstream to ensure reliable operation and ease of maintenance. Type 301 stainless steel is not an acceptable alternative.
C.	Fans:  Forward curved centrifugal type mounted on steel shaft, with belt drive, bearings with ABMA STD 9 or ABMA STD 11 L-10 life at 40,000 hours, with extended grease fittings.
D.	Motors and Drives:
1.	Motor: Single speed (1800 rpm), totally enclosed fan cooled (TEFC), cooling tower duty, inverter-duty type designed per NEMA Standard MG1, Section IV, Part 31. Motor will be located on a heavy-duty motor base, adjustable by a single threaded bolt-and-nut arrangement. 
2.	Fan Drive System: Belt Drive designed for minimum 150 percent motor nameplate power. Removable steel screens or panels protect the fan drive and all moving parts.
E.	Distribution Section: 
1.	Polyvinyl chloride piping header and branches with non-clog ABS plastic spray nozzles. The branches and spray nozzles will be held in place by snap-in rubber grommets, allowing quick removal of individual nozzles or complete branches for cleaning or flushing.
2.	Spray Water Pump(s): The closed circuit cooling tower will include an appropriate number of close coupled, bronze-fitted centrifugal pump and motor assemblies equipped with mechanical seal, and piped from the suction connection to the water distribution system. The pump motor(s) will be the totally enclosed fan cooled (TEFC) type, premium efficiency suitable for _____ volts, ___ phase, and ____ hertz electrical service. The system will include a metering valve and bleed line to control the bleed rate from the pump discharge to the overflow connection.
F.	Heat Transfer Coils:
1.	Galvanized Steel: The coil will be constructed of continuous serpentine all prime surface steel, be pneumatically tested at 375 psig (2,685 kPa), and be hot-dip galvanized after fabrication. The coil will be designed for free drainage of fluid and will be ASME B31.5 compliant. Maximum allowable working pressure will be 300 psig (280 psig for coils supplied with a CRN).
----- Alternate for Half Coil Finning -----
2.	Extended Surface Coil for Half the Rows: The coil will be constructed of continuous serpentine all prime surface steel with half the rows finned at 5 fins per inch for seasonal wet/dry operation. The coils will be pneumatically tested at 375 psig (2,685 kPa) and be hot-dip galvanized after fabrication. ASME B31.5 compliant and sloped for complete draining. Maximum allowable working pressure will be 300 psig (280 psig for coils supplied with a CRN).
----- Alternate for Full Coil Finning -----
3.	Extended Surface Coil for All the Rows: The coil will be constructed of continuous serpentine all prime surface steel with all the rows finned at 5 fins per inch for seasonal wet/dry operation. The coils will be pneumatically tested at 375 psig (2,685 kPa), and be hot-dip galvanized after fabrication. ASME B31.5 compliant and sloped for complete draining. Maximum allowable working pressure will be 300 psig (280 psig for coils supplied with a CRN).
----- Alternate for 304 Stainless Steel Coil -----
4.	304 Stainless Steel: Coil(s) will be constructed of type 304 stainless steel serpentine tube. Tubes will be sloped for free drainage and coil assembly will be pneumatically tested at 375 psig (2,685 kPa). Coil(s) will be ASME B31.5 compliant.
----- Add for ASME Coil-----
5.	ASME Coils: Coil(s) will be designed and constructed to meet the requirements of ASME Boiler and Pressure Vessel Code, Section VIII, Division 1, and bear the U stamp.
G.	Drift Eliminators: Three-pass design to minimize drift loss, made of PVC material. 
H.	Basin Water Level Control: 
1.	PVC, balanced piston type make-up valve with plastic float.
----- ALTERNATE for Electric Water Level Controller-----
2.	Electric water level control with NEMA 4 enclosure, solid state controls, LED status light, and stainless steel water level sensing electrodes. Number and position of probes provided to sense the following: high water level, low water level, high water alarm level, low water alarm level, heater safety cutout, and automatic solenoid valve. Include all necessary mounting hardware. 
2.04	ACCESSORIES
A.	Circular access doors will be provided for easy access to the make-up water assembly and suction strainer for routine maintenance.
B.	(Optional) Electric Immersion Heaters: In pan suitable to maintain temperature of water in pan at 40 degrees F (4.4 degrees C) when outside temperature is 0 degrees F (-17.7 degrees C) [OR -20 degrees F (-28.9 degrees C)] and wind velocity is 15 mph (25 kph); immersion thermostat and float control operate heaters on low temperature when the pan is filled. Heaters will be constructed of copper.
C.	 (Optional) Basin Sweeper Piping: The cold water basin of the cooling tower will be equipped with PVC sump sweeper piping with plastic eductor nozzles. The piping must be designed specifically for the size and shape of the basin to ensure full agitation. 
D.	(Optional) Vibration Switch:  
1.	Provide a mechanical local reset vibration switch. The mechanical vibration cutout switch will be guaranteed to trip at a point so as not to cause damage to the cooling tower. To ensure this, the trip point will be set in a frequency range of 0 to 3,600 RPM and a trip point of 0.2 to 2.0 g’s.
----- ALTERNATE for Electronic Vibration Switch-----
2.	Provide an electronic remote reset vibration switch with contact for BAS monitoring. Wiring will be by the installing contractor. The electronic vibration cutout switch will be set to trip at a point so as not to cause damage to the cooling tower. To ensure this, the trip point will be set in a frequency range of 2 to 1000 Hertz and a trip point of 0.45 in/sec (0.0114 m/sec).
E.	(Optional) Access Packages: See submittal documents for access package requirements. Platforms and ladders must ship assembled from cooling tower manufacturer.
1.	Exterior Ladder with Handrails: An aluminum ladder with galvanized steel safety cage and safety gate will be provided for access to the top of the unit. 1-1/4 inch (32 mm) galvanized steel pipe handrail will be provided around the perimeter of the cooling tower cells. The handrails will be provided with knee and toe rails and will conform to OSHA requirements applicable at the time of shipment. Galvanized steel drift eliminators will be supplied to provide dependable walking surface.
F.	Sound Attenuation: 
1.	(Optional) Intake Sound Attenuation: The unit will be equipped with intake sound attenuators consisting of fiberglass acoustical baffles encased in steel to further reduce sound levels.
2.	(Optional) Discharge Options: The unit will be equipped with a tapered hood lined with sound absorbing fiberglass acoustical baffles to reduce sound levels from the top of the unit.
G.	(Optional) (Alternate without sound attenuation) Tapered Discharge Hood: The unit will be equipped with a tapered hood to increase discharge velocity or to raise the discharge to the top of an enclosure.
	PART 3 EXECUTION
3.01	INSTALLATION
A.	Install in accordance with manufacturer's instructions.
B.	Provide the services of the manufacturer's field representative to supervise rigging, hoisting, and installation, allowing for minimum of one eight-hour day per tower.
C.	Install tower on structural steel beams as instructed by manufacturer.
D.	Connect condenser water piping to tower. Pitch condenser water supply to tower and condenser water suction away from tower. 
E.	Connect make-up water piping to tower. Pitch to tower. 
F.	Connect overflow and drain to acceptable discharge point as required by jurisdiction.
3.02	FIELD QUALITY CONTROL
A.	See Quality Requirements, for additional requirements.
B.	Provide the services of the manufacturer's field representative to inspect tower after installation and submit report prior to start-up, verifying installation is in accordance with specifications and manufacturer's recommendations.
3.03	SYSTEM START-UP
A.	Start-up tower in presence of and instruct Owner 's operating personnel.
3.04	SCHEDULES
A.	Cooling Towers
1.	Drawing Code:
2.	Location:
3.	Manufacturer:
4.	Model Number:
5.	Cooling Capacity
a.	Water Flow Rate:
b.	Entering Water Temperature:
c.	Leaving Water Temperature:
6.	Entering Air WB Temperature:
7.	External Static Pressure (For Indoor Applications):
8.	Number of Fan Motors:
9.	Motor Size:
10.	Fan Motor Electrical Characteristics: [_____] Volts, Three-Phase, 60 Hz.
11.	Pump Motor Electrical Characteristics: [_____] Volts, Three-Phase, 60 Hz.
12.	Basin Heaters No. and Type:
a.	END OF SECTION