Engineering Specifications for Vertex™ Evaporative Condensers
Part 1 – GENERAL
1.1	SUMMARY
A.	This Section includes factory-assembled evaporative condenser(s) of counterflow blow-through design with single side forced-draft air intake.
B.	Furnish and install, factory assembled evaporative condenser(s) of counterflow blow-through design, with single side air inlet, conforming in all aspects to the specifications and schedule as shown on the plans. 

1.2	SUBMITTALS
A.	Product Data: Include rated capacities, refrigerant charge, fan performance data, sound power characteristics, weights, electrical data, installation instructions, furnished specialties, water piping sizes, drain line piping sizes, and accessories. 
B.	Wiring diagrams.
C.	Operation and maintenance data. 
1.3	QUALITY ASSURANCE
A.	The manufacture will have a Management System certified by an accredited registrar as complying with the requirements of ISO-9001 to ensure consistent quality of products and services. Manufacturers that are not ISO-9001 will not be accepted. 
B.	Factory Testing: Equipment manufacturer will be capable of testing the operation of the condenser in the manufacturer’s own test facility. Test facilities will 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.
C.	Wind and Seismic Forces: The unit will be designed in accordance with ASCE/SEI 7-16.  

1.4	COORDINATION
A.	Coordinate size and location of mechanical, electrical, and structural connections.
B.	Coordinate installation of roof curbs, equipment supports, and roof penetrations.  
C.	Coordinate installation of discharge air ductwork. Those items are specified in Division 23. 
D.	Coordinate installation of main water inlet line and drainage/overflow piping. These items are specified in Division 22.

1.5	WARRANTY 
A.	The manufacturer’s standard equipment warranty will be for a period of one year from the date of startup or eighteen months from the date of shipment, whichever ends first. The manufacturer will, in addition, provide a 5-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, will be provided for fan motor(s) when space heaters are field-wired at time of initial installation.
Part 2 – PRODUCTS
2.1	MANUFACTURERS
A.	Available Manufacturers: Subject to compliance with requirements, manufacturers offering products that may be incorporated into the Work include the following: 
1.	BAC – Baltimore Aircoil Company
2.2	MANUFACTURED UNITS
A.	Description: 
1.	Coil Casing Section: Evaporative condenser coil section will consist of a refrigerant condensing coil, a spray water distribution system, and drift eliminators as indicated by the manufacturer. 
2.	Fan and Basin Section: Section will consist of spray water collection basin, integral air intake plenum, and fans with drive components. Units must have self-aligning pan and casing sections. Provide built-in alignment pins to guide upper section into place, allowing for faster rigging and assembly. 
3.	Accessibility: As standard, unit will be provided with:
a.	Access door(s) at least 68” in height. This may exempt the condenser from being considered a confined space. Check your local code for confirmation.
b.	Integral step and grab bar at access door for safe ingress and egress.
c.	Internal walkway allowing easy access to basin, drive components, and underside of coil. 
B.	Counterflow Condenser Characteristics and Capacities:
1.	Characteristics: Refer to latest refrigeration plans and schedules. 
2.	Capacity: The evaporative condenser(s) will be warranted by the manufacturer to have condensing capacity of __________ BTUH (kW) heat rejection, operating with _________ refrigerant and _______ºF (ºC) condensing temperature and ________ºF(ºC) entering wet-bulb temperature. 
2.3	MATERIALS
A.	Fan and Casing Panels: 
1.	Galvanized Corrosion Resistant Construction: Unless otherwise noted in this specification, all steel panels and structural members must be constructed from heavy-gauge, G-235 (Z700 metric) mill galvanized steel, with cut edges given a protective coating of zinc-rich compound. 
2.	(Alternate) Thermosetting Hybrid Polymer: Unless otherwise noted in this specification, all steel panels and structural members will be protected with the thermosetting hybrid polymer. The corrosion resistance system will consist of G-235 (Z700 metric) mill 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. Any 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 it will be able to withstand 6000 hours of 5% salt spray per ASTM B117 without blistering, chipping, or loss of adhesion.
b.	When X-scribed to the steel substrate it will 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
c.	Will withstand impact of 160 in-lbs per ASTM D2794 without fracture or delamination of the polymer layer.
d.	Will withstand 6000 hours of ultraviolet radiation equivalent to 120,000 hours of noontime sun exposure without loss of functional properties.
e.	Will withstand 200 thermal shock cycles between -25ºF and +180ºF (-32˚C and 82˚C) without loss of adhesion or other deterioration.
f.	Will withstand 6000 hours of exposure to 60 psi (42,184 kg/m2) water jet without signs of wear or erosion. 

3.	 (Alternate) Type 304 Stainless Steel: Unless otherwise noted in this specification, all steel panels and structural members must be constructed of type 304 stainless steel and assembled with type 304 stainless steel nut and bolt fasteners.
4.	(Alternate) Water Contact Areas Constructed of Type 304 Stainless Steel: Unless otherwise noted in this specification, the basin and the adjacent panels which may come in contact with spray water will be constructed from type 304 stainless steel. The rest of the unit will be constructed from G-235 hot-dip galvanized steel.
B.	Basin: 
1.	The basin will be constructed of heavy-gauge G-235 (Z700 metric) mill galvanized steel panels and structural members. The basin will have single side air inlet and integral air plenum. The basin will be sloped towards the pump inlet and will include: a drain/clean-out connection; a steel strainer; a corrosion resistant make-up valve; overflow connection; and a water recirculation pump assembly. 
2.	(Alternate) Type 304 Stainless Steel Basin: The basin will be constructed out of type 304 stainless steel with seams welded at the factory. A bolted stainless steel basin is not an acceptable alternative. The basin will have single side air inlet and integral air plenum. The basin will be sloped towards the pump inlet. The basin will have a 5 year leak proof warranty on all factory welded seams.
3.	(Alternate) TriArmor™ Corrosion Protection System on the Basin: The basin will be protected with the TriArmor™ Corrosion Protection System. The system will 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 will seal all factory seams in the cold water basin to ensure a corrosion resistant and water tight construction, and will be warranted against leaks and corrosion for ten (10) years from date of shipment. Field applied polyurethane or polyurethane applied directly to galvanized steel is not an acceptable alternative. A welded type 304 or 316 stainless steel basin will be an acceptable alternative, provided the basin is warranted against leaks and corrosion for a period of at least 10 years. A bolted type 304 stainless steel basin is not be an acceptable alternative.
4.	Drain/cleanout connection will be located in the basin to allow draining of recirculating water. Connection material to match basin.
5.	Lift-out steel strainer will be supplied with perforated openings sized smaller than the water distribution nozzle orifices and an integral anti-vortexing hood to prevent air entrainment. Strainer material to match basin.
6.	Overflow connection will be provided in the basin to protect against recirculating water spillage. Connection material to match basin

C.	Evaporative Condensing Coil:
1.	Hot Dipped Galvanized Coil: The refrigerant condensing coil will be fabricated of continuous lengths of all prime surface steel at the manufacturer’s own facility, and hot-dip galvanized after fabrication (HDGAF). The maximum allowable working pressure will be 300 psig (280 psig for coils supplied with a CRN). The refrigerant condensing coil will be designed for low pressure drop with sloping tubes for free drainage of liquid refrigerant. The refrigerant condensing coil will be ASME B31.5 compliant.
2.	(Alternate) Stainless Steel Coil: The refrigerant condensing coil will be fabricated of corrosion resistant 304 stainless steel.
3.	(Alternate) Galvanized steel coil with additional circuit: The condensing coil will be fabricated of continuous lengths of all prime surface steel at the manufacturer’s own facility, and hot-dip galvanized after fabrication. The condensing coil will be designed for low pressure drop with sloping tubes for free drainage of fluid. The maximum allowable working pressure will be 300 psig (280 psig for coils supplied with a CRN). The coil header will be partitioned. Each coil segment will include an inlet and outlet connection to allow independent operation of each segment.
4.	(Alternate) ASME coil: The condensing coil will be fabricated of continuous lengths of all prime surface steel at the manufacturer’s own facility, and hot-dip galvanized after fabrication. The condensing coil will be pneumatically tested at 375 psig (2,865 kPa). The condensing coil will be designed for low pressure drop with sloping tubes for free drainage of fluid. The maximum allowable working pressure will be 300 psig (280 psig for coils supplied with a CRN). The condensing coil will be designed, built, tested and stamped in accordance with Section VIII, Division 1, of the ASME Boiler and Pressure Vessel Code. 
 
2.4	COMPONENTS
A.	 Water recirculation pump: 
1.	Pump will 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. The pump will have a bronze impeller.  The pump will be installed so that it may drain freely when the basin is drained. The pump assembly will include an integral metering valve and bleed line to control the bleed rate from the pump discharge to the overflow connection. The pump motor will be totally enclosed fan cooled (TEFC) type suitable for _____ V, ____ phase, ______ Hz electrical service.
2.	Remote sump option: On installations requiring a remote sump, the evaporative condenser will be constructed to accommodate the use of an independent sump and pump for recirculating water (by others). The recirculating water pump, steel strainer, make-up valve, and integral bleed line assemblies will be omitted from the evaporative condenser scope of supply. The evaporative condenser will be supplied with a cold water basin outlet sized and located as indicated on the drawings for gravity drain to the remote sump.
B.	Make-up Valve 
1.	Valve must be corrosion resistant and supplied with a large diameter, foam-filled plastic float arranged for easy adjustment.
2.	(Alternate) The evaporative condenser manufacturer will provide an electric water level control (EWLC) system. The system will consist of water level sensing and control units in quantities and locations as indicated on the drawings. Each water level sensing and control unit will consist of the following: 
a.	NEMA 4 enclosure with gasketed access cover; solid state controls including all necessary relays and contacts to achieve the specified sequence of operation.
b.	Stainless steel water level sensing electrodes with brass holder. 
c.	Provide PVC union directly below the control enclosure to facilitate the removal and access of electrodes and control enclosure. 
d.	(Optional) The number and position of water level sensing electrodes will be provided to sense the following: high water level, low water level, high water alarm level, low water alarm level, and heater safety cutout.
C.	Fan(s): 
1.	Air will enter the evaporative condenser through the axial fan assemblies and integral air plenum. Each fan assembly will be a single-stage design with fan mounted on a shaft with discharge guide vanes for increased fan efficiency. 
a.	Fans will be heavy-duty, axial flow type with an aluminum alloy hub, corrosion resistant stainless steel hardware, and glass reinforced polypropylene blades. 
b.	Fans are driven by a one-piece, multi-groove neoprene/polyester belt designed for a minimum of 150% of the motor nameplate horsepower.
c.	Fan cylinders will have curved inlets for efficient air entry. 
d.	Internal fan partitions must be included to isolate each fan. This allows the unit to continue operating with limited performance loss in the case of a fan or motor failure.
e.	Bearings: Fan shafts will be mounted in heavy-duty, self-aligning, grease-packed, re-lubricatable ball bearings with eccentric locking collars, designed for a minimum L10 life of 95,000 hours (1,000,000 hours average life). Bearing lubrication lines will be extended to the exterior of the unit. Bearings will be easily accessible from inside the unit. 
2.	(Alternate - included with EC Motors 2.4 D3) Fans are integrated into the motor assembly outlined in Section 2.4 D3. Assembly includes motor, fan, fan guard, and mounting plate. All exposed materials must be nylon, aluminum, powder coated steel, or stainless steel. Fan guard must be in compliance with OSHA standard 1910 for machine guarding. 

D.	Fan Motors:
1.	Comply with requirements in Division 23 Section "Common Motor Requirements for HVAC Equipment."
2.	Fan motors and drives will be located at the front base of the unit to facilitate access without requiring access to the inside of the unit. Fans and motors will be located in the dry entering airstream to provide greater reliability and ease of maintenance. Fan motor bases will be adjustable for belt tensioning by adjusting a single nut. Fan motor(s) will be totally enclosed fan cooled (TEFC) type, premium efficiency/VFD ready with a 1.15 service factor, suitable for _____ V, ____ phase, ______ Hz electrical service and will be mounted on an easily adjusted, heavy-duty motor base. Fan motors will comply with NEMA Standard MG 31, Section IV, Part 31.
3.	(Alternate) - Motors must be electronically commutated (EC) with UL and CE markings. Fan motor(s) must be factory installed and wired to a common terminal box
a.	Fan motor(s) will have a minimum ingress protection of IP55 or better.
b.	Fan motor(s) will have maintenance-free, permanently-lubricated, sealed ball bearings. 
c.	Fan motor(s) will operate with integrated commutation electronics offering high efficiency across the entire speed range and optimal acoustic performance at minimal installation expenditure. 
d.	Fan Motor(s) will have an integrated variable speed control (VSC).
e.	Fan motor(s) will be thermal overload protected (TOP).
f.	Fan motor(s) will have integrated phase loss protection.
g.	Fan motor(s) are to be UL listed to UL1004 and/or UL2111, CSA C22.2 No. 77 and/or No.100. 9. 
h.	Fan Motor Speed Controller:  The fan controller must allow the user to control the fan speed the following ways:
i.	Analog Input (0-10VDC, 10-0VDC or 4-20mA)
ii.	Modbus TCP/IP, BACnet IP
i.	Fan System Protection: Provide factory-wired integral electronics within the motors that will detect upset conditions, prompting the factory-provided controls to shut down the fan motor(s) in that specific module and issue an alarm warning to alert the Operator to check the fan.
j.	For applications with 575 Volt electrical supply, a transformer must be provided by others. 
E.	Spray Water Distribution System: 
1.	Water will be distributed evenly over the coil at a minimum flow rate of 4.5 gpm/ft2 (3.1 lps/m2) to ensure complete wetting of the coil at all times. The water distribution system will have an operating pressure of 2 psig (115 kPa) at the evaporative condenser spray water inlet connection.
2.	Spray branches: Spray branches will be held in place by snap-in rubber grommets, allowing quick removal of complete branches for cleaning or flushing. Spray branches will be removable without the use of any tools and constructed out of Schedule 40 PVC.
3.	Nozzles: Large-diameter, non-clog, 360° plastic distribution nozzles spaced across the coil face area, will utilize a two-stage diffusion pattern to provide overlapping, umbrella spray patterns. Nozzles will have a minimum of 0.25” (6.35 mm) protrusion inside the spray branches to ensure unimpeded water flow between regular cleanings of the water distribution system. Nozzles will be removable without any tools for cleaning. Directional nozzles are not acceptable.
F.	Drift Eliminators:
1.	Removable PVC drift eliminators must be positioned to prevent moisture from leaving the evaporative condenser and incorporate a minimum of three (3) changes in air direction.
2.	(Alternate) Removable steel drift eliminators must be positioned to prevent moisture from leaving the evaporative condenser and incorporate a minimum of three (3) changes in air direction.

OPTIONAL COMPONENTS
G.	External Access:
1.	The unit will be provided with a factory assembled, field-installed external platform with an access ladder and handrails complying with OSHA standards and regulations to provide access to the top of the evaporative condenser. Platforms not completely assembled are not acceptable.  External platform will have a 24” (610 mm) wide non-skid walking surface and 42” (1,220 mm) high safety railings. Optional safety cage will be available to meet OSHA requirements as necessary. See project drawings for additional external platform requirements. 
H.	Basin Sweeper Piping: 
1.	The basin of the unit will be equipped with PVC sump sweeper piping for a separator (supplied by others).
I.	Basin Heaters: 
1.	Evaporative condenser will be provided with basin heaters to prevent freezing of the water in the cold water basin when the evaporative condenser is idle. The basin heaters will be selected to maintain +40° F (4.4° C) basin water temperature at a _____ambient temperature and 10 mph (16.1 km/hr) wind speed. Basin heaters will be electric immersion type controlled by a remote thermostat with the sensing bulb located in the basin water. Basin heaters will be provided with a factory-installed low water level cutout switch to prevent heater operation unless the heater elements are fully submerged.
J.	Vibration Cutout Switch: 
1.	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 unit. To ensure this, the trip point will be set in a frequency range of ___ to ___ Hertz and a trip point of ____ in/sec (____m/sec).
K.	Redundant Pump System: 
1.	The unit will be supplied with a fully redundant spray pump. The pump system will be designed to allow for complete isolation of one pump while the other pump is in operation. This will allow for servicing or replacement of a pump without downtime. Factory supplied valves can be operated manually or with customer-supplied actuators.