Engineering Specifications for Series V Evaporative Condensers

Part 1: General

A. General: Furnish and install, _____ factory assembled evaporative condenser(s) of counterflow blow-through design, with single side entry, conforming in all aspects to the specifications and schedule 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 and _______ºF (ºC) condensing temperature and ________ºF(ºC) entering wet-bulb temperature.

C. Warranty: The manufacturer’s standard equipment warranty shall 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 shall, in addition, provide a 5-year mechanical drive warranty covering the fans, fan shafts, bearings, sheaves, supports, and fan motors.

D. Factory Testing: Equipment 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 manufacture shall 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 certified shall provide an additional one-year warranty to the customer at no additional cost.

Part 2: Parts

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 a refrigerant condensing coil, a spray water distribution system, and drift eliminators as indicated by the manufacturer.

1. The refrigerant condensing coil shall be fabricated of all prime surface steel at the manufacturer’s own facility, and hot-dip galvanized after fabrication.

a. The refrigerant condensing coil shall be tested at 375 psig (2,687 kPa) air pressure under water.

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 at a minimum flow rate of 4.5 gpm/ft2 (3.1 lps/m2) to ensure complete wetting of the coil at all times by large-diameter, non-clog, 360° plastic distribution nozzles 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. Directional nozzles shall not be acceptable.

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.

c. Nozzles shall 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.

3. Removable PVC drift eliminators shall be positioned to prevent moisture from leaving the evaporative condenser and incorporate a minimum of three (3) changes in air direction.

2.03 Basin Assembly

A. The evaporative condenser shall include a basin assembly consisting of cold water basin with pump assembly and fan assemblies with single side air inlet and integral air plenum.

1. 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. Drain/cleanout connection shall be located in the cold water basin to allow removal of recirculating water.

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. Corrosion resistant make-up valve shall be supplied with a large diameter plastic float arranged for easy adjustment.

d. Overflow connection shall be provided in the cold water basin to protect against recirculating water spillage.

e. 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 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 _____ V, ____ phase, ______ Hz electrical service.

f. 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 an operating pressure of 2 psig (115 kPa) at the evaporative condenser spray water inlet connection.

VC2 and VXMC Models

2. Air shall enter the evaporative condenser through the axial fan assemblies and integral air plenum.

a. Fans and motors shall be located in the dry entering airstream to provide greater reliability and ease of maintenance.

b. Fan motors and drives shall be located at the front base of the unit to facilitate access without requiring access to the inside of the unit.

c. Fan cylinders shall have curved inlets for efficient air entry.

d. Each fan assembly shall contain two axial-flow fans mounted in series on a common shaft with discharge guide vanes between the fans for increased fan efficiency.

e. Fans shall be heavy-duty, axial flow 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.

i. Fan shafts shall be mounted in heavy-duty, self aligning, grease-packed relubricatable ball bearings with eccentric locking collars, designed for a minimum L10 life of 40,000 hours (280,000 hours average life).

ii. Bearing lubrication lines shall be extended to the exterior of the unit.

iii. Fan and motor sheaves shall be fabricated from corrosion-resistant materials.

f. Fan motor(s) shall be totally enclosed fan cooled (TEFC) type with a 1.15 service factor, suitable for _____ V, ____ phase, ______ Hz electrical service and shall be mounted on an easily adjusted, heavy-duty motor base. g. Integral air plenum shall contain additional guide vanes to ensure uniform airflow into the coil casing section.

VC1 Models

2. Air shall enter the evaporative condenser through the centrifugal fan assemblies and integral air plenum.

a. Fans and motors shall be located in the dry entering air stream to provide greater reliability and ease of maintenance.

b. Fan housings shall have curved inlet rings for efficient air entry and rectangular discharge cowls that extend into the pan to increase fan efficiency and prevent water from entering the fans.

c. Fan housings on units more than 8’ wide shall be split to facilitate the removal of the fan shaft.

d. Fan(s) shall be heavy-duty, centrifugal flow type mounted on a steel shaft with heavy-duty, self-aligning, relubricatable bearings with cast iron housings, designed for a minimum L10 life of 40,000 hours (280,000 hours average life).

e. Fan motor(s) shall be totally enclosed fan cooled (TEFC) type with a 1.15 service factor, suitable for _____ V, ____ phase, ______ Hz electrical service and shall be mounted on an easily adjusted, heavy-duty motor base. Special moisture protection shall be furnished on the windings, shafts, and bearings.

VCL Models

2. Air shall enter the evaporative condenser through the centrifugal fan assemblies and integral air plenum.

a. Centrifugal fan assemblies shall be located adjacent to the casing and the cold water basin to minimize overall unit height.

b. Fan housings shall have curved inlet rings for efficient air entry and rectangular discharge cowls which extend into the pan to increase fan efficiency and prevent water from entering the fans.

c. Fan housings shall be split to facilitate the removal of the fan shaft.

d. Fan(s) shall be heavy-duty, centrifugal flow type mounted on a steel shaft with heavy-duty, self-aligning, relubricatable bearings with cast iron housings, designed for a minimum L10 life of 40,000 hours (280,000 hours average life).

e. Fan motor(s) shall be totally enclosed fan cooled (TEFC) type with a 1.15 service factor, suitable for _____ V, ____ phase, ______ Hz electrical service and shall be mounted on an easily adjusted, heavy-duty motor base. Special moisture protection shall be provided on the windings, shafts and bearings.

2.04 Optional Equipment Specifications

A. Evaporative condenser shall be provided with basin heaters to prevent freezing of the water in the cold water basin 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 factory-installed low water level cutout switch to prevent heater operation unless the heater elements are fully submerged.

B. Evaporative condenser shall be supplied with dedicated motors and drives so that each fan can be cycled independently, and an internal baffle shall be supplied to deter air bypass within the unit.

C. Evaporative condenser shall 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.

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 to meet OSHA requirements as necessary.

D. Evaporative condenser shall be supplied with the ENERGYMISER ® Fan System to improve part load efficiency and provide system redundancy in case of a motor failure.

1. The ENERGY-MISER® Fan System shall include the main fan motor as listed in the manufacturer’s published literature and a pony motor sized for approximately 1/3 of design horse power and 2/3 of design fan speed to optimize energy savings during non-design load conditions.

E. BALTIGUARD PLUS™ Fan System: Two single speed fan motors, one sized for load, the other sized for 1/3 of the full load horespower shall be provided in each cell for capacity control and standby protection from drive or motor failure. The manufacturer of the equipment shall suppy controls for the larger motor, a VFD for the smaller motor and factory programmed logic controller to maximize energy saving for off peak load and wet-bulb conditions.