Engineering Specifications for CXVB Evaporative Condensers 
Part 1: General 
A. General: Furnish and install, ________ factory assembled evaporative condenser(s) of induced draft design with vertical discharge, conforming in all aspects to the specifications and schedules as shown on the plans. 
B. Capacity: The evaporative condenser(s) shall be warranted by the manufacturer to have condensing capacity of _____ BTUH (kW) heat rejection, operating with _____ refrigerant at ___ °F(ºC) condensing temperature and ___°F(ºC) entering wet-bulb temperature. 
C. Warranty: The manufacturer shall provide a five-year mechanical drive warranty covering the fans, fan shafts, bearings, sheaves, supports, and fan motors. An additional two years of warranty, for a total of seven (7) years, shall be provided for fan motor(s) when space heaters are field-wired at time of initial installation. The manufacturer’s standard equipment warranty for the balance of the components shall be for a period of one year from the date of startup or eighteen months from the date of shipment, whichever ends first. 
D. Factory Testing: The manufacturer shall be capable of testing the operation of the condenser in the manufacturer’s own test facility. Test facilities shall be capable of simulating design conditions, including but not limited to design wet-bulb, airflow, refrigerant mass flow rate, refrigerant condensing temperature, and total heat rejection. 
E. Quality Assurance: The manufacturer shall have a Management System certified by an accredited registrar as complying with the requirements of ISO-9001:2008 to ensure consistent quality of products and services. Manufacturers that are not ISO-9001:2008 certified shall provide an additional one-year warranty to the customer at no additional cost. 
F.  The evaporative condenser shall be designed, and certified for earthquake loads in accordance with the 2009 IBC and ASCE/SEI 7-05.  The unit shall be suitable for applications with Design Spectral Acceleration at Short Period (SDS) for z/h = 1.0 up to _____g with a Component Importance Factor (Ip) of 1.0 and 1.5.  The unit shall be certified by the manufacturer as maintaining refrigerant containment following an earthquake.  The certification shall be based on analysis and verified by full-scale, shake table testing, and shall be reviewed and approved by a licensed professional engineer independent of the manufacturer.  Units not provided with evidence of compliance shall not be an acceptable alternative.

G.  The evaporative condenser shall be designed for wind loads in accordance with the 2009 IBC and ASCE/SEI 7-05.  The unit shall be suitable for applications with a design horizontal wind pressure up to _____psf.  Design wind pressure shall be calculated in accordance with Sections 6.5.15 and 6.5.15.1, as applicable, of ASCE/SEI 7-05.  A concurrent uplift pressure equivalent to the horizontal pressure shall be considered in the unit design.  Unit resistance shall be determined in accordance with the material design specifications referenced in the 2009 IBC, and shall be reviewed and approved by a licensed professional engineer independent of the manufacturer.
Part 2: Products 
2.01 Evaporative Condenser Materials and Components 
A. General: All steel panels and structural elements shall be constructed from heavy-gauge, G-235 (Z700 metric) hot-dip galvanized steel, with cut edges given a protective coating of zinc-rich compound. 
2.02 Coil Casing Assembly 
A. The evaporative condenser shall include a coil casing section consisting of refrigerant condensing coil, spray water distribution system, drift eliminators, and air plenum with fan assemblies as indicated by the manufacturer. 
1. The refrigerant condensing coil shall be fabricated of continuous lengths of all prime surface steel at the manufacturer’s own facility, and hot-dip galvanized after fabrication. 
a. The refrigerant condensing coil shall be pneumatically tested at 375 psig (2,687 kPa). 
b. The refrigerant condensing coil shall be designed for low pressure drop with sloping tubes for free drainage of liquid refrigerant. 
c. The refrigerant condensing coil shall be ASME B31.5 compliant and coils shipping into Canada shall be supplied with a CRN. 
2. Water shall be distributed evenly over the coil to ensure complete wetting of the coil at all times. Large-diameter, non-clog, 360° plastic distribution nozzles shall be spaced across the coil face area in Schedule 40 PVC spray branches. Nozzles shall utilize a two-stage diffusion pattern to provide overlapping, umbrella spray patterns that create multiple intersection points with adjacent nozzles. 
a. Nozzles and spray branches shall be observable and accessible for cleaning from the outside of the evaporative condenser during condenser operation without the removal of other components. 
b. Spray branches and nozzles shall be held in place by snap-in rubber grommets, allowing quick removal of individual nozzles or complete branches for cleaning or flushing. 
3. Removable PVC drift eliminators shall be positioned to prevent moisture from entering the air plenum and incorporate a minimum of three (3) changes in air direction. 
4. Fan(s) shall be heavy-duty, axial type with aluminum alloy blades driven by a one-piece, multi-groove neoprene/ polyester belt designed for a minimum of 150% of the motor nameplate horsepower. 
a. Fan(s) and shafts shall be supported by heavy-duty, self aligning, grease-packed ball bearings with moisture-proof seals and integral sealer rings, designed for a minimum L10 life of 80,000 hours.
b. Fan and motor sheaves shall be fabricated from corrosion resistant materials. 
c. Fan motor(s) shall be totally enclosed fan cooled (TEAO) type, premium efficiency/VFD ready with a 1.0 service factor, suitable for _____ V, ____ phase, ______ Hz electrical service and shall be mounted on an easily adjusted, heavy-duty motor base. Fan motors shall comply with NEMA Standard MG 31, Section IV, Part 31.

d. The motor shall be furnished with double-sealed, permanently lubricated bearings and special moisture protection on windings, shafts and bearings. 
e. Air plenum shall provide a minimum of 48˝ (1220 mm) clearance under the motor base to provide comfortable working space for service personnel.
f. The evaporative condenser shall be provided with extended lubrication lines with standard grease fittings for lubricating the fan shaft bearings from the outside base of the condenser. 
2.03 Basin Assembly 
A. The evaporative condenser shall include a basin assembly consisting of cold water basin with pump assembly, heat transfer section for spray water cooling with integral drift eliminators, and wide spaced air inlet louvers. 
1. The cold water basin shall be constructed of heavy-gauge steel panels and structural members. Basin shall include a depressed section with drain/cleanout connection. The basin area under the fill surface shall be sloped toward the depressed section to facilitate cleaning. 
OR
1. Unless otherwise noted in this specification, all steel panels and structural members shall be protected with a thermosetting hybrid polymer.  The process shall consist of G-235 (Z700 metric) hot-dip galvanized steel prepared in a four-step (clean, pre-treat, rinse, dry) process with an electrostatically sprayed, thermosetting, hybrid polymer fuse-bonded to the substrate during a thermally activated curing stage and monitored by a 23-step quality assurance program. Coatings other than the thermosetting hybrid polymer must be submitted to the engineer for pre-approval. Approved equals must have undergone testing, resulting in the following results as a minimum:

1. When X-scribed to the steel substrate it shall be able to withstand 6000 hours of 5% salt spray per ASTM B117 without blistering, chipping, or loss of adhesion;

2. When X-scribed to the steel substrate it shall be able to withstand 6000 hours of exposure to acidic (pH=4.0) and alkaline (pH=11.0) water solutions at 95ºF (35˚C) without signs of chemical attack;

3. Shall withstand impact of 160 in-lbs per ASTM D2794 without fracture or delamination of the polymer layer;

4. Shall withstand 6000 hours of ultraviolet radiation equivalent to 120,000 hours of noontime sun exposure without loss of functional properties;

5. Shall withstand 200 thermal shock cycles between - 25ºF and +180ºF (-32˚C and 82˚C) without loss of adhesion or other deterioration; 

6. Shall withstand 6000 hours of exposure to 60 psi (42,184 kg/m2) water jet without signs of wear or erosion.

The cold water basin shall be protected with the TriArmor® Corrosion Protection System. The system shall consist of G-235 galvanized steel encapsulated with a thermosetting hybrid polymer further protected by a polyurethane liner factory applied to all submerged surfaces. The polyurethane barrier shall seal all factory seams in the cold water basin to ensure a corrosion resistant and water tight construction, and shall be warranted against leaks and corrosion for five (5) years. Field applied polyurethane or polyurethane applied directly to galvanized steel is not an acceptable alternative. A welded type 316 stainless steel basin shall be an acceptable alternative; provided the basin is warranted against leaks and corrosion for a period of at least 5 years. A bolted type 304 stainless steel basin shall not be an acceptable alternative. 
OR
1. The cold water basin shall be constructed of heavy-gauge type 304 stainless steel panels and structural members, with all welded seams. The welded stainless steel basin shall be leak tested at the factory. Basin shall include a depressed section with drain/cleanout connection. The basin area under the fill surface shall be sloped toward the depressed section to facilitate cleaning. 
2. The cold water basin shall include: a drain/clean-out connection; a steel strainer; a corrosion resistant make-up valve; overflow connection; and a water recirculation pump assembly. 
a. Cold water basin shall be designed so that the strainer, makeup valve and float, and pump assembly are easily accessible without removing any of the unit panels or other components. 
b. Lift-out steel strainer shall be supplied with perforated openings sized smaller than the water distribution nozzle orifices and an integral anti-vortexing hood to prevent air entrainment. 
c. Water recirculation pump shall be a close-coupled, bronze fitted centrifugal pump equipped with a mechanical seal, mounted on the basin and piped from the suction strainer to the water distribution system.
i. The pump shall be installed with adequate drains so that it may drain freely when the basin is drained.
ii. The pump assembly shall include an integral metering valve and bleed line to control the bleed rate from the pump discharge to the overflow connection. 
iii. The pump motor shall be totally enclosed fan cooled (TEFC) type suitable for _____ volt, ____ phase, ______ Hz electrical service. 
d. On installations requiring a remote sump, the evaporative condenser shall be modified to accommodate the use of an independent sump and pump for recirculating water (by others).
i. The recirculating water pump, steel strainer, make-up valve, and integral bleed line assemblies shall be omitted from the evaporative condenser scope of supply.
ii. The evaporative condenser shall be supplied with a cold water basin outlet sized and located as indicated on the drawings for gravity drain to the remote sump. 
iii. The water distribution system shall have a design operating pressure of 1 psig (108.25 kPa) at the evaporative condenser spray water inlet connection. 
3. The heat transfer section shall consist of fill with integral drift eliminators for cooling the spray water leaving the coil to optimize the thermal performance of the evaporative condenser. 
a. The fill and integral drift eliminators shall be formed from self-extinguishing (per ASTM-568) polyvinyl chloride (PVC) having a flame spread rating of 5 per ASTM E84. 
b. The fill and integral drift eliminators shall be impervious to rot, decay, fungus, and biological attack. 
4.  As standard, the evaporative condenser shall be provided with a moveable ladder with fixed ladder supports to provide access to the fan drive system and coil assembly. 
5.  As standard, the evaporative condenser shall be provided with an internal walk way at the access door to facilitate servicing the unit. 
4.  The combined inlet shields shall be UV resistant PVC, installed on the air inlet face to minimize air resistance, prevent water splash out, minimized sunlight exposure to reduce the potential for algae growth in the cold water basin.  
2.04 Optional Equipment Specifications 
A. Evaporative condenser shall be provided with basin heaters to prevent freezing of the recirculating water when the evaporative condenser is idle. 
1. The basin heaters shall be selected to maintain +40°F (4.4°C) basin water temperature at a 0°F
(-17.8°C) ambient temperature and 10 mph (16.1 km/hr) wind speed.
2. Basin heaters shall be electric immersion type controlled by a remote thermostat with the sensing bulb located in the basin water. 
3. Basin heaters shall be provided with a low water level cutout switch to prevent heater operation unless the heater elements are adequately submerged. 
C. Evaporative condenser shall be supplied with dedicated motors and drives so that each fan can be cycled independently. 
D. The evaporative condenser shall be provided with a factory assembled, field-installed external platform with an access ladder and handrails to provide access to the top of the evaporative condenser. 
1. External platform shall have a 24˝ (610 mm) wide non-skid walking surface and 42˝ (1,220 mm) high safety railings. 
2. Optional ladder safety cage shall be available as necessary. 
E.  The unit shall be equipped with a mechanical equipment removal davit. The motor shall be lowered from the mechanical equipment supports down to grade. Davit shall 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. 

F.  The evaporative condenser shall ship from the factory with the fan motor(s) (and vibration cutout switch) wired to terminal blocks encased in a 304 stainless steel NEMA 3R enclosure, mounted on the outside of the tower. No casing penetrations shall be permitted in the field.

G.  The air inlet on the top of the unit shall be supplied with combined inlet shields.  These blockers shall be UV resistant PVC and shall minimize sunlight exposure on the coil to reduce the potential for algae growth.