Cooling TowersME- Building Group

SECTION 236500 – COOLING TOWERS

PART 1 - GENERAL

1.1RELATED DOCUMENTS

  1. Drawings and general provisions of the Contract, including General and Supplementary Conditions and Division01 Specification Sections, apply to this Section.

1.2SUMMARY

  1. This Section includes factory-fabricated, induced-draft, crossflow cooling towers.

1.3SUBMITTALS

  1. Product data including rated capacities, pressure drop, fan performance data, weights (shipping, installed, and operating), installation instructions, start-up instructions, and rating curves with selected points clearly indicated.
  2. Shop drawings indicating dimensions, weight loadings, weight distribution, and clearances required around and between construction elements such as beams, columns, and walls.
  3. Coordination drawings indicating structural supports, piping rough-in requirements, wiring rough-in requirements (determine spaces reserved for electrical equipment), and access requirements around other work (including working clearances to mechanical controls and electrical equipment).
  4. Wiring diagrams for power supply wiring to cooling towers and ladder-type wiring diagrams for interlock and control wiring. Clearly differentiate between factory-installed and field-installed wiring. Provide voltage and amperage requirements for each circuit.
  5. Maintenance data for each cooling tower. Include parts lists for tower fill, water distribution system, fans, bearings, controls, basin heaters, and all accessories.
  6. Certified performance curves plotting leaving-water temperature (LWT) against wet-bulb temperature (WBT).

1.4QUALITY ASSURANCE

  1. Manufacturer's Certification: The performance of the cooling tower shall be independently certified by the Cooling Technology Institute (CTI) in accordance with CTI Standard 201.
  2. NEMA Compliance: Provide electric motors and electrical components required as part of factory-fabricated cooling towers that comply with applicable NEMA Standards.
  3. NEC Compliance: Provide cooling towers according to NFPA 70 "National Electrical Code."

Retain "ASHRAE/IESNA90.1 Compliance" Paragraph below to require compliance with ASHRAE/IESNA90.1. LEEDPrerequisiteEA2 requires compliance with ASHRAE/IESNA90.1. LEEDCreditEA1 requires efficiency in excess of minimum efficiency required by ASHRAE/IESNA90.1.

  1. ASHRAE/IESNA90.1 Compliance: Applicable requirements in ASHRAE/IESNA90.1, Section6 - "Heating, Ventilating, and Air-Conditioning."
  2. FM Approval: Cooling towers to be Factory Mutual approved without a sprinkler.
  3. Noise:
  4. Sound pressure level, resulting from tower operation, shall not exceed 80 DBA at 100 feet from towers, not to exceed local noise ordinances, when measured in accordance with ARI standard 575 and the National Machine Tool Builders Association NMTBA Noise Measurement Techniques latest edition. Data shall comply with the requirements of Chrysler’s sound level specification for industrial machinery and equipment.
  5. Manufacturer shall clearly state exceptions regarding the ability of the proposed vendor in complying with this requirement.
  6. If manufacturer cannot meet the specified noise level and the manufacturer of the proposed equipment is capable of demonstrating that he has fully explored engineering solutions without positive results, the manufacturer shall submit complete octave-band analysis, together with his identification of probable noise sources. Data shall include readings at each test point from each load condition in sufficient detail to permit calculation of associated noise exposure. Submit manufacturer’s information as to nature, construction type, and expected noise reduction for corrective schemes such as enclosures and include cost of such corrective schemes in bid.

1.5DELIVERY, STORAGE, AND HANDLING

  1. The manufacturer is to deliver equipment to the jobsite. Delivery is to be coordinated and controlled with the Owner and Installing Contractor. Off loading, storage, and handling is to be by the Installing Contractor.
  2. Delivery of units shall be in accordance with the project requirements. Units shall not be stored on site. All warehousing costs if required to meet the project schedule are to be included in this Contract.
  3. Shipments shall be clearly identified as follows:
  4. Installing Contractor’s name.
  5. Owner’s name and address.
  6. Manufacturer’s identifying code as agreed upon by manufacturer and Owner, for example, contract number, shop order number, and bid package number.
  7. Mark numbers or tag numbers to facilitate cataloging, storage, and retrieval of materials.
  8. Crates, boxes, or other containers used for shipment of materials shall have packing lists attached in protective cover in a conspicuous location. An additional packing list shall be placed inside container. Packing lists shall clearly identify contents of container.
  9. Shipments shall be delivered to project site. Manufacturer shall notify the Owner at least 1 week in advance of exact shipping and receiving dates for equipment.
  10. Securely close component connections to protect mating surfaces and keep out foreign matter.
  11. Protect units to ensure against damage from improper handling or exposure to natural elements. Instrument, electrical, and control components shall be wrapped in waterproof material and boxed or crated. Fragile assemblies shall be crated. Ungalvanized or nonstainless steel exposed steel parts shall be coated with protective compounds.
  12. Materials, regardless of the method of shipment, shall be the responsibility of the manufacturer until such time as agreed upon by Owner.

1.6SCHEDULING AND SEQUENCING

  1. Notify Owner and construction Manager one week in advance of each shipping date.

1.7WARRANTY

  1. Warranty on Parts and Labor: Provide written warranty, agreeing to replace/repair, within warranty period, at no cost to the Owner, all parts with inadequate and defective materials and workmanship, including leakage, breakage, improper assembly, or failure to perform as required.
  2. Warranty Period: Five years from date of project VI date as defined in Section 17 of the “Supplementary Conditions”.

1.8OWNER’S INSTRUCTIONS

  1. Operation And Maintenance Manuals
  2. Ninety days prior to start-up of equipment, submit to the Owner, 5 copies of operating and maintenance instruction manuals bound in durable stiff covers.
  3. Instruction manuals shall contain the following:
  4. Index on book form of all component and diagram data sheets.
  5. Description and assembly drawings of each item of equipment.
  6. Parts nomenclature.
  7. Wiring and piping diagrams.
  8. Procedures for start-up and operation of unit.
  9. Instructions for disassembly and reassembly of all items of equipment furnished as required for normal operation and maintenance.
  10. Sequence of operation for the equipment.
  11. Normal set points and limits for all controls.
  12. Final settings and adjustments established for start-up tests.
  13. In addition to the folded insert drawings and data sheets incorporated in the 5 copies of the manual, all large diagrams and schematics shall be furnished in as-built condition on mylar reproducible sheets.
  14. Training
  15. Instruction of Owner’s Personnel: Furnish technically qualified personnel, who are fully familiar with this equipment, for the purpose of instructing selected personnel employed by the Owner during start-up in the proper techniques for operation and maintenance of the equipment.
  16. The instruction includes “hands on” training of Owner’s personnel in operation and maintenance of the equipment.
  17. Include 40 hours training in 4 hour segments.

1.9COMMISSIONING

  1. Equipment start-up include costs required to furnish technically qualified personnel, who are fully familiar with his equipment and control systems, for the purpose of equipment start-up, including adjustments of all equipment furnished, initial running and testing of systems for proper operation and performance.

1.10MAINTENANCE

  1. Service Organization:
  2. Submit the name, address, and telephone number of nearest field service headquarters actually staffed with Engineers engaged in such work.
  3. Proposals will be allowed to include factual engineering information of special design features which are intended to increase efficiency, reduce maintenance costs, and improve reliability.
  4. Spare Parts Lists: Submit a list of parts recommended to maintain units in full operation under normal operating conditions, including long lead time items in excess of 1 week delivery. List should include expected life and recommended replacement schedule for furnished equipment. Selection shall take into account vulnerability to normal wear, availability and excepted shelf life. Also advise special devices and tools required for maintenance and calibration of all equipment furnished. Lists shall indicate current total prices of recommended and optional parts and materials.

PART 2 - PRODUCTS

2.1MANUFACTURERS

  1. Manufacturers: Subject to compliance with requirements, provide cooling towers manufactured by one of the following:
  2. Baltimore Aircoil Company.
  3. Marley Cooling Tower Company.
  4. Owner approved substitute.

2.2INDUCED-DRAFT, CROSSFLOW COOLING TOWERS

  1. Description: Induced-draft, crossflow cooling tower that is factory fabricated and factory assembled using manufacturer's standard design, materials, and construction according to published product information and these specifications. The cooling tower systems are defined as follows:
  2. Chilled Water.
  3. Compressed Air.
  4. The cooling towers are to be grouped in five cell sections with maintenance access available between the sections. The fan deck shall be extended between each group to provide one continuous fan deck. One of the five cells will be for redundant service.
  5. Fan Description: Propeller fan.
  6. Fan Blade: Cast aluminum with adjustable pitch.
  7. Fan Drive: Gear drive speed reducer with remote lube level indication. Belt drives are not acceptable.
  8. Fan Bearings: Self-aligning ball bearings or bronze sleeve bearings. Provide external, extended grease lines and fittings.
  9. Fan Motor: Totally enclosed, fan-cooled, cooling tower duty, premium efficiency, T-frame motor in accordance with Chrysler NPEM 105 Standards, water proofed for inside tower service.
  10. Manufacturers:

1)Reliance.

2)U.S. Motors.

3)Westinghouse.

  1. Motor Speed: Two speed, double winding.
  2. Vibration Cut-out Switch: Metrix Vibralert, Marley M-1 or equal, double pole, double throw switch to de-energize fan motors if excessive vibration occurs due to fan imbalance. Switch outputs will be wired directly to PLC input cards for alarm and to the fan motor starters for shutdown. Provide one per tower cell. The fan/motor/drive assembly shall have adequate vibration isolation to prevent transmission of vibration to the tower support steel. PMC Beta vibration switches are not acceptable.
  3. Drives are to be laser aligned by the tower manufacturer to plus or minus .004 in. after installation.
  1. Hot Water Basins: Hot water distribution basins shall be the open gravity type and constructed of heavy-gauge, G235 hot-dip galvanized steel. Plastic metering orifices shall be provided to assure even distribution of the water over the wet deck surface. Lift-off distribution covers shall be constructed of heavy gauge G-235 hot-dip galvanized steel and designed to withstand a 50 psf live load or 200 pound concentrated load. Internal inlet piping shall be of non-metallic construction.
  2. All piping connections shall be bottom inlet through bottom of cooling tower cells.
  3. Casing: Galvanized steel conforming to ASTMA653 with Coating Designation G210. Tower to withstand 100 MPH wind load.
  4. Collecting Basins: Each cold water basin shall be welded and constructed of 304 stainless steel with the following accessories:
  5. Removable basin strainer with openings smaller than nozzle orifices.
  6. Overflow connection. Minimum size 3 inches in each cell.
  7. Bottom drain connection. Minimum size 4 inches in each cell.
  8. Bottom connection (bolt hole pattern) for use with external equalizer lines.
  9. Fill Material: Formed PVC, resistant to rot, decay, and biological attack with a maximum flame-spread rating of 5 per ASTME84 and fabricated, formed, and installed by the manufacturer to ensure that water breaks up into droplets. Fill is to be protected by screen covers.
  10. Drift Eliminator Material: Formed PVC resistant to rot, decay, and biological attack with a maximum flame spread rating of 5 per ASTME84. Drift losses shall not exceed 0.002 percent.
  11. Louver Material: Formed PVC resistant to rot, decay, and biological attack with a maximum flame spread rating of 5 per ASTME84. Provide galvanized steel air inlet screens.
  12. Water Level Control: Level probe with outputs direct to chiller control panel, to provide high level alarm, make-up valve off, make-up valve on, and low level alarm. Locate probe in center cell. Output (contact closures) from level probe to be wired direct to Facility Management System.
  13. Basin Heaters: Sufficient size to maintain basin water temperature at 40 degF when ambient temperature is minus5degF and wind velocity is 10 mph.
  14. Heater Type: Stainless steel electric immersion heaters, 480 Volt.
  15. Provide basin heater control panels in weatherproof enclosures. Panels will ship loose for field mounting and wiring to the respective devices by the electrical contractor. One panel shall provide service to the basin heaters of each cooling tower cell. Each control panel shall include a disconnect switch, contactor of suitable capacity to serve the basin heaters, fusing, control transformer, low level heater protection, and thermostatic control of the basin heaters.
  16. Access Doors: Provide on both endwalls of each cell. Provide lockout and continued space entry placards at each door.
  17. Plenum Walkway: Galvanized bar grating walkway extending from one endwall access door to the other.
  18. Handrails: Galvanized-steel pipe rails and kickplates that comply with requirements of 29 CFR 1910.23 (OSHA). Provide around each Tower System.
  19. Ladders: Galvanized steel pipe rails that comply with requirements of 29 CFR 1910.27 (OSHA). Provide two end-mounted ladders for each tower.
  20. Safety Cage: Galvanized steel pipe rails that comply with requirements of 29 CFR 1910.27 (OSHA). Provide with each ladder.
  21. Fire Protection: The towers shall be constructed of fireproof material throughout. It is the Owner’s intent not to sprinkler these towers for fire protection. Manufacturer is to ensure that units offered have or are capable of obtaining FM approval for materials at no cost to the Owner.
  22. Hardware: Regular bolting and fasteners shall be galvanized steel, except cold water basin which shall be stainless steel. Furnish anchor bolts of AISI 300 Series stainless steel. For weldments, use malleable iron in preference to cast iron.
  23. Equipment Performance Schedule

Service / Cooling Tower Water
Quantity / 1
Nominal Tonnage / 375 tons/cell
Cells per Tower / 5
Tower Flow Rate (GPM) / 600 gpm/cell
Ent. Water Temp. (F) / 100
Lvg. Water Temp. (F) / 85
Design Wet Bulb / 77
Fan Motor HP (per cell)* / 10
Voltage/Phase/Hertz / 480/3/60
Number of water level controls / 1 in center cell

*HP is estimated, manufacturer shall provide actual HP required with bid.

* 1 cell is standby.

2.3SIDE STREAM FILTRATION SYSTEM

  1. Manufacturer:
  2. Vortisand.
  3. Approved substitute.
  4. Operation:
  5. The filtration system shall be designed to filter water in cooling towers and open recirculation loop systems. Contaminants removal down to .45 micron nominal. Water entering the vessel structure creates a centrifugal force to thrust contaminants against the perimeter of the vessel and above the swirl of water, holding the contaminants in inventory until expelled to waste during backwash.
  6. The filtration capacity of the system shall be 200 gpm. Backwash cycle shall be automatically operated and shall not exceed an 8 minute period. A separate source of clean chlorinated water (< 1 NTU) is required for backwashing. Maximum working pressure of system will be 100 psig, maximum temperature of system will be 105 deg. F.
  7. Filter System: The filter system will consist of 2 vertical stainless steel pressure vessels. Spacing around and above the filtering system will be a minimum of 3 feet.
  8. Filter Vessels: Filter vessels shall be constructed of #304 stainless steel with 100% weld penetration. Each vessel will be built and certified to the ASME code standards. Section VIII, Division 1 for 125 psig.
  9. Filter Media: The sand portion of the filter media shall be suitable for a cooling tower application.
  10. Automatic Control Panel:
  11. The system shall be equipped with a Programmable Logic Controller (PLC) to control valve sequence and timing of the backwash and will be SONITEC or equal. Filtration/backwash cycles are started and ended by a differential pressure sensor, timing device or a push button sending a signal to the stager which operates the valve sequence. The filter pump will be stopped and the filter system will be isolated from service and each vessel will be individually backwashed before returning to service. If the system has not stored enough contaminants to activate the pressure sensor, the 24 hour timer will force the system into backwash cycle minimizing the possibility of bacteria and algae build-up within the vessels.
  12. The control system will be composed of the following items:
  13. Backwash and filter pump motor indicating light.
  14. Pump motor starter and main disconnect switch.
  15. Programmable Logic Controller.
  16. Non-resettable backwash counter mounted on the panel door to indicate the number of times the filter has backwashed.
  17. Step-down transformer for 115 VAC controls.
  18. Audible alarm with reset silencer for pump failure and stager failure to execute the backwash sequence.
  19. Push button for manual backwash (override).
  20. Dry contact for Building Automation System.
  21. Differential pressure switch.
  22. Control panel shall be UL or CDA certified.
  23. Control box shall be NEMA 12.
  24. Valves: Stainless ball valves with pneumatic actuator, 125 psig working pressure, Aquamatic type, with cast iron body, stainless steel trim and pneumatic controls. Each valve will have a pressure indicator to visualize the position of the diaphragm.
  25. Piping and Fittings: Galvanized material with a pressure rating of not less than 100 pounds per square inch (gauge). A flow controller shall be supplied to limit the flow during backwash.
  26. Filter Accessories:
  27. The filtration system shall be provided with all of the necessary trim for complete operating filter arrangements including the following:
  28. Pressure gages to indicate when filter media backwash is necessary, a total of 2 per system. One gage will be stationed before the filter inlet and will be marked "influent" and the other gage will be stationed at the filter outlet and will be marked "effluent." Gage dial size will be no less than 2-1/2 inches with indicated measurements from 0 to 100 psi. Gages will be Ashcroft or equal.
  29. A transparent tube which shows filter media containment removal during backwash cycle will by Hayward SP72 or equal.
  30. Pump/Motor:
  31. Pump shall be centrifugal type, Goulds or equal, capable of delivering 200 gpm.
  32. Pump shall be connected to a 5 HP, 460 volts, 3 phase, 60 cycle motor. Pump and motor will conform to the above characteristics without overloading along the full length of pump curve.

PART 3 - EXECUTION