Section 236500
Cooling Towers
	PART 1 GENERAL
1.01	SECTION INCLUDES
A.	Open-circuit, induced-draft, cross-flow cooling towers.
1.02	REFERENCE STANDARDS
A.	ASME B31.5 - Refrigeration Piping and Heat Transfer Components 2016.
B.	ASME Section VIII Boiler and Pressure Vessel Code
C.	ASTM A123/A123M - Standard Specification for Zinc (Hot-Dip Galvanized) Coatings on Iron and Steel Products 2017.
D.	ASTM A653/A653M - Standard Specification for Steel Sheet, Zinc-Coated (Galvanized) or Zinc-Iron Alloy-Coated (Galvannealed) by the Hot-Dip Process 2018.
E.	ASTM B117 - Standard Practice for Operating Salt Spray (Fog) Apparatus 2018.
F.	ASTM E84 - Standard Test Method for Surface Burning Characteristics of Building Materials 2018b.
G.	CTI STD-201 OM - Operations Manual for Thermal Performance Certification of Evaporative Heat Rejection Equipment 2017.
H.	CTI STD-201 RS - Performance Rating of Evaporative Heat Rejection Equipment 2017.
I.	CTI STD-111 - Gear Speed Reducers for Application on Industrial Water Cooling Towers; 2009.
J.	ISO 9001 - Quality management systems -- Requirements 2015.
K.	NEMA MG 1 - Motors and Generators 2017.
L.	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, required clearances, 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, 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 twenty 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 [_____] years of experience and approved by manufacturer.
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.
C.	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 seven (7) with direct drive fan system from date of shipment. Included VFD will have 5 year warranty. 
	PART 2 PRODUCTS
2.01	MANUFACTURERS
A.	Open-Circuit, Induced-Draft, Cross-Flow Cooling Towers:
1.	Baltimore Aircoil Company; Series 3000: www.baltimoreaircoil.com
2.02	MANUFACTURED UNITS
A.	Provide units for outdoor use, factory-assembled, sectional, induced draft with vertical discharge, and fan assemblies built into casing.
2.03	COMPONENTS
A.	Cold Water Basin:
1.	Heavy-gage galvanized steel with access doors at both ends of tower to air plenum. Provide sloped basin with drain/clean-out connection.
----- ALTERNATE for TriArmor Basin -----
2.	Tri-layer protection system consisting of G-235 galvanized steel, a thermosetting hybrid polymer, and a polyurethane liner factory applied to all submerged surfaces. A welded Type 316 stainless steel basin is an acceptable alternative.
----- ALTERNATE for 304 Stainless Steel -----
3.	Sloped with depressed section with drain/clean-out connection. Type 304 welded stainless steel panels and structural members. Basins with bolted seams or constructed of 301 stainless steel are not acceptable.
----- ALTERNATE for 316 Stainless Steel-----
4.	Sloped with depressed section with drain/clean-out connection. Type 316 welded stainless steel panels and structural members. Basins with bolted seams are not acceptable.
-----ALTERNATE for Basinless Unit-----
5.	The unit shall be provided without an integral cold water basin. The unit shall be mounted on a separate concrete cold water basin provided by others, to allow cooling water to pass directly from the fill into the basin.
B.	Water Distribution System
1.	The hot water distribution basins will be gravity-fed and accessible from the outside of the unit for service or inspection while unit is in operation. Included weir dams will accommodate a flow range of 50% to 100% of the design flow rate. Lift-off distribution covers shall be constructed of steel and designed to withstand a 50 psf (244 kg/m2) live load or 200 pound (90.7 kg) concentrated load. 
----- ALTERNATE for EVERTOUGH Construction-----
2.	The hot water distribution basins will be gravity-fed and accessible from the outside of the unit for service or inspection while unit is in operation. Basins must be constructed of corrosion-resistant pultruded fiberglass reinforced polyester (PFRP) or type 316 stainless steel. Included weir dams will accommodate a flow range of 50% to 100% of the design flow rate. Lift-off distribution covers shall be constructed of Type 304 stainless steel and designed to withstand a 50 psf (244 kg/m2) live load or 200 pound (90.7 kg) concentrated load. 
C.	Casing Panels and Framework:
1.	Casing panels will be constructed of corrosion and UV-resistant fiberglass reinforced polyester (FRP) or Type 304 stainless steel to minimize maintenance requirements and prolong equipment life.
----- ALTERNATE for Thermosetting Hybrid Polymer Panels-----
2.	Casing panels will be constructed of 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 panels-----
3.	Casing panels and framework will be constructed of G235 galvanized steel.
----- ALTERNATE for 304 stainless steel panels-----
4.	Casing panels, framework, and fasteners will be constructed of Type 304 stainless steel. Type 301 stainless steel is not an acceptable alternative.
----- ALTERNATE for 316 stainless steel panels-----
5.	Casing panels, framework, and fasteners will be constructed of Type 316 stainless steel. Type 301 or 304 stainless steel is not an acceptable alternative.
D.	Air Inlet Louvers
1.	Fiberglass Reinforced Polyester (FRP): Air Inlet louvers shall be separate from the fill and removable to provide easy access for inspection of the air/water interface at the louver face. Louvers shall prevent water splash out during fan cycling and be constructed of maintenance free, corrosion and UV resistant FRP.
----- ALTERNATE for steel louvers-----
2.	Steel Louvers: Air Inlet louvers shall be separate from the fill and removable to provide easy access for inspection of the air/water interface at the louver face. Louvers shall prevent water splash out during fan cycling. Material of construction must match steel grade of casing panels. 
----- ALTERNATE for Combined inlet shields (PVC)----
3.	PVC Inlet Shields: Louver sections shall be individually removable sections, The combined inlet shields shall be UV resistant PVC, installed on the air inlet face to minimize air resistance, prevent water splash out, and minimize sunlight exposure to reduce the potential for algae growth in the cold water basin.  
E.	Fans:  Multi blade, axial type, with belt drive, bearings with ABMA STD 9 or ABMA STD 11 L-10 life at 80,000 hours, with extended grease fittings. Fans must factory test-mounted, balanced, and aligned to ensure reliable operation and ease of maintenance. Fan type will be selected to meet sound ratings published on equipment schedule. 
F.	Motors:
1.	Single speed (1800 rpm) premium efficiency cooling tower duty motor mounted on adjustable steel base. 
----- ALTERNATE ENDURADRIVE Fan System -----
2.	Direct Drive Motor: See Direct Drive Fan System (2.03 G)
G.	Fan Drive System:
1.	Direct Drive Fan System: The motor will be directly connected to the fan shaft within the airstream, eliminating the need for couplings, right-angle gears, belts, or sheaves.  
a.	Quality Assurance 
1)	Tower thermal performance must be certified per CTI STD-201 
2)	Manufactured under ISO 9001 approved quality assurance program 
3)	Vibration tested per ICC-ES AC 156; must meet local Sds requirement but not less than 0.50 
4)	Analyzed for structural resonance per CTI STD-163; maximum resonance must not exceed 0.36 in/sec. 
5)	Tested and certified to operate continuously at 104°F ambient wet bulb temperature 
6)	Minimum 7-year warranty 
7)	Compatible VFD supplied by tower manufacturer; see VFD specification for details 
8)	(OPTIONAL) Factory Test: The motor will be wired and tested prior to shipping. Factory test will include:
(a)	Installation of unit on a test stand for a visual/audible inspection to confirm no excess movement or unusual noises exist
(b)	Wiring of motor to a VFD
(c)	Running the motor to a specified speed/frequency and taking measurements of power draw to ensure appropriate loading is being achieved
(d)	Documentation of testing results supplied in the customer’s documents 
b.	General  
1)	CSA Label and CE mark for safety compliance 
2)	Totally Enclosed Air Over (TEAO) IP56 rating 
3)	Interior permanent magnet rotor construction; synchronous design; magnets enclosed inside the rotor lamination; magnets with high temperature grade capable of 200°C conditions without loss of magnetization 
4)	Compliance with NEMA MG 1 part 31 standards for definite-purpose inverter-fed motors suitable for 2000 volt peak at 10,000 volt per microsecond 
c.	Components 
1)	Salient pole permanent magnet design rotor resulting in no I²R losses 
2)	Stator consisting of low-loss C5a coated electrical steel 
3)	Integral stator cooling fins, not a shaft mounted fan, for controlling rotor and stator temperatures during operation 
4)	Class H insulation system rated at 1850 Volts peak, and thermally-rated wire when tested per ASTM D-2307 for 600,000 hours extrapolated life at 155°C minimum 
5)	Bearing isolator (seal) on motor shaft provided with shaft grounding device, utilizing two carbon grounding brushes to eliminate bearing currents 
6)	Shaft sealed by three O-rings, with two conductive O-rings to properly ground the bearing, eliminating damaging currents in the bearings 
7)	Oversized conduit box with provisions for grounding inside 
8)	Integral condensate drain system 
9)	Three normally closed thermostats, one per phase 
10)	Open ball bearings with a minimum L10 life of 100,000 hours 
11)	Bearings sized to handle unbalanced loads based on an ISO Balance Grade of 6.3  
12)	Re-greaseable bearing system including stainless steel inlet fitting and grease drain provided with square stainless-steel square head pipe plugs 
13)	E-coat primer on cast iron parts prior to application of top coat  
14)	Enhanced cooling tower duty paint that withstands 1000 hour salt fog test 

----- ALTERNATE Belt Drive -----
2.	Belt Drive: Designed for minimum 150 percent motor nameplate power. Fan and motor sheave(s) shall be fabricated from corrosion-resistant materials to minimize maintenance and ensure maximum drive and powerband operating life. Belt tension must be adjusted
----- ALTERNATE Internal Gear Drive -----
3.	Gear Drive with Internal Motor: Industrial duty, right angle gear designed in accordance with CTI STD-111. Gear must be rated for service factor of 2.0 with forward and reverse operation. Oil level fill port and sight glass located on the gear. Connected to motor by flexible coupling.
----- ALTERNATE External Gear Drive -----
4.	Gear Drive with External Motor: Industrial duty, right angle gear designed in accordance with CTI STD-111. Gear must be rated for service factor of 2.0 with forward and reverse operation. Oil level fill port and sight glass located on the gear. Connected to motor with a drive shaft.
H.	Fan Guard: 
1.	Welded steel rod and wire guard, hot dipped galvanized after fabrication. Installed over fan discharge. 
-----ALTERNATE for stainless steel fan guard-----
2.	Welded stainless steel rod and wire guard, placed over fan discharge. 
I.	(Optional) Mechanical Equipment Removal Davit: The unit will be equipped with a mechanical equipment removal davit. The motor will lower from the mechanical equipment supports down to grade. Davit will attach to the unit without the need for tools. If tools are required for davit installation or removal, provide (1) davit for each motor provided.
J.	Gravity-fed Distribution: Hot water basins will be have removable covers for inspection while unit is in operation, weir dams and metering nozzles for at least 50 percent turndown capability. Gravity flow nozzles shall be snap-in type for easy removal.
K.	Balancing Valves: Heavy-duty butterfly valves shall be provided at the hot water inlet connections. These valves shall include cast iron bodies, elastomer seat and steel operating 
-----ALTERNATE for Easy Connect Option-----
L.	Single Inlet Connection: Each tower cell shall be furnished with a single water inlet connection complete with the means to automatically balance flow rates to the hot water basins.
M.	Fill: 
1.	The fill and integral drift eliminators will be formed from self-extinguishing (per ASTM-568) polyvinyl chloride (PVC) having a flame spread rating of 25 per ASTM E84 and shall be impervious to rot, decay, fungus and biological attack. The fill is suitable for entering water temperatures up to and including 130°F (54.4°C). The fill must be manufactured, tested and rated by the cooling tower manufacturer and are elevated above the cold water basin floor to facilitate cleaning.  If louvers are attached to fill, a spare set of fill sheets are required in case of premature icing and scaling. 
----ALTERNATE for High-Temp Fill----
2.	The fill and integral drift eliminators will be formed from self-extinguishing (per ASTM-568) polyvinyl chloride (PVC) having a flame spread rating of 25 per ASTM E84 and shall be impervious to rot, decay, fungus and biological attack. The fill is suitable for entering water temperatures up to and including 140°F (60.0°C). The fill must be manufactured, tested and rated by the cooling tower manufacturer and are elevated above the cold water basin floor to facilitate cleaning.  If louvers are attached to fill, a spare set of fill sheets are required in case of premature icing and scaling. 
N.	Drift Eliminators: Three pass PVC, drift loss limited to 0.005 percent of total water circulated.
O.	Basin Water Level Control: 
1.	Corrosion resistant PVC make-up valve with plastic float for easy adjustment of operating water level.
----- ALTERNATE for Electric Water Level Controller-----
2.	Electronic 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, and heater safety cutout. Include all necessary mounting hardware. 
2.04	PERFORMANCE REQUIREMENTS
A.	This section is based on specific selections of equipment, and these selections relate to selection of related equipment, Section 232123 - Hydronic Pumps and Section 236433 - Modular Water Chillers. In substituting equipment, ensure that performance selection criteria matches that specified or that the selection of related equipment is acceptable or is revised to suit.
B.	Capacity:
1.	Water Flow: [_____] gpm ([_____] L/sec).
2.	Entering Water Temperature: [_____] degrees F ([_____] degrees C).
3.	Leaving Water Temperature: [_____] degrees F ([_____] degrees C).
4.	Entering Air WB Temperature: [_____] degrees F (______ degrees C).
5.	Ambient Air DB Temperature/Switchpoint: [_____] degrees F (______ degrees C).
C.	Electrical Characteristics:
1.	[____] hp ([____] kW).
2.	[____] volts, single phase, 60 Hz.
2.05	ACCESSORIES
A.	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 degress 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.
B.	Basin Sweeper Piping: The cold water basin of the cooling tower shall 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 reach the 
C.	Fan Cylinder Extension: To extend the height of the tower equal to the surrounding enclosure, the cooling tower shall be provided with _____ft (mm) of fan cylinder extension. The fan cylinder extension shall match the construction of the fan deck.
D.	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.
2.	(ALTERNATE) Provide an electronic remote reset vibration switch with contact for BAS monitoring. Wiring shall be by the installing contractor. The electronic vibration cutout switch shall 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.	Access Packages: See submittal documents for access package requirements. Platforms and ladders must ship assembled from cooling tower manufacturer.
1.	Plenum Access: Two hinged access doors must be provided for access into the plenum section. Include an internal walkway for inspection and maintenance. All working surfaces shall be able to withstand 50 psf (244 kg/m²) live load or 200 pound (90.7 kg) concentrated load. Other components of the cooling tower, i.e. basin and fill/drift eliminators, shall not be considered an internal working surface. Cooling tower manufacturers that promote these surfaces to be used as a working platform shall provide a two-year extended warranty to the Owner to repair any damage to these surfaces caused during routine maintenance.
2.	Fan Deck Ladder with Handrails: An aluminum ladder with galvanized steel safety cage and safety gate will be provided for access to the fan deck. Access door or service platforms are not acceptable. 1-1/4 inch (32 mm) galvanized steel pipe handrail shall be provided around the perimeter of the cooling tower cells. The handrails shall be provided with knee and toe rails and shall conform to OSHA requirements applicable at the time of shipment.
3.	External Platforms: Easy access to the hot water basins for inspection of spray water distribution, even during tower operation, will be provided by external platforms at the louver face. Fan deck ladders and handrails, which add to the overall height of the tower, are not acceptable. Platforms and ladders must ship assembled from cooling tower manufacturer.
4.	Internal Platform: An internal platform shall be provided in the plenum section to provide for inspection and maintenance. All working surfaces shall be able to withstand 50 psf (244 kg/m^2) live load or 200 pound (90.7 kg) concentrated load. Platforms and ladders must ship assembled from cooling tower manufacturer.
5.	Access Door Platform: An external galvanized steel access platform at the access door of the unit(s) provides access to the spray distribution system or internal plenum. An aluminum ladder and 1-1/4 inch (32 mm) galvanized steel pipe safety railing is included with the platform. This option meets pertinent OSHA standards. Platforms and ladders must ship assembled from cooling tower manufacturer.
	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. Refer to Section 232113.
E.	Connect make-up water piping to tower. Pitch to tower. Refer to Section 221005.
F.	Connect overflow, bleed, and drain, to acceptable discharge point as required by jurisdiction.
3.02	FIELD QUALITY CONTROL
A.	See Section 014000 - 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 STARTUP
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.	Number of Fan Motors:
8.	Motor Size:
9.	Heaters No. and Type:
a.	END OF SECTION