Evaporative Condensers


cATC Evaporative Condenser


The cATC line of evaporative condensers represents Evapco’s commitment to product development. The line is comprised of 24 models ranging in size from 128 to 357 nominal ammonia tons (551 kW to 1,538 kW). The induced draft counterflow condensers are designed especially for easy maintenance and long, trouble-free operation.

Design Features

Drive System

Unit Specifications

Design Features


The cATC Evaporative Condenser is an Advanced Technology, induced draft counterflow design condenser featuring EVAPCO’s patented THERMAL-PAK ® COIL – the most efficient in the industry. The counterflow design provides the cATC Evaporative Condenser with inherently better operational and maintenance features.

Drive System


The cATC Evaporative Condenser features the highly successful EVAPCO POWER-BAND Belt Drive System engineered for heavy-duty operation. The POWER-BAND Drive System has consistently provided trouble-free operation in the most severe duty evaporative condenser applications.

Unit Specifications


Furnish and install, as shown on the plans, an Evapco model _________ induced draft, counterflow evaporative condenser with a condensing capacity of _________ MBH total heat of rejection when operating with _________ refrigerant at ______ °F (ºC) condensing temperature with a ______ °F (ºC) design wet bulb temperature.


Basin and Casing


The basin and casing shall be constructed of G-235 (Z-600 Europe) hot-dip galvanized steel for long life and durability. Standard basin accessories shall include overflow, drain, type 304 stainless steel strainers, and brass make-up valve with plastic float.


Belt Drive

Fan Motor


_________ horsepower (kW) totally enclosed air over ball bearing fan motor(s), with 1.15 service factor shall be furnished suitable for service on _________ volts, _________ hertz, and _________ phase. Motor(s) shall be mounted on an adjustable base which allows the motor to swing to the outside of the unit for servicing.




The fan drive shall be a multigroove, solid back V-belt type with taper lock sheaves designed for 150% of the motor nameplate horsepower. The belt material shall be neoprene reinforced with polyester cord and specifically designed for evaporative condenser service. Fan and motor sheaves shall be aluminum alloy construction. The fans and fan sheaves shall be mounted on the shaft with a specially coated bushing to provide maximum corrosion protection. Belt adjustment shall be accomplished from the exterior of the unit. Bearing lube lines shall be extended to the exterior of the unit for easy maintenance.


Axial Propeller Fans



shall be heavy duty axial propeller type statically balanced. The fans shall be constructed of aluminum alloy blades, installed in a closely fitted cowl with venturi air inlet. Fan screens shall be galvanized steel mesh and frame, bolted to the fan cowl.


Fan Shaft Bearings


Fan shaft bearings shall be heavy duty self-aligning ball type with grease fittings extended to the outside of the unit. Materials shall be stainless steel balls with chrome steel races and zinc plated housing for corrosion resistance. Bearings shall be designed for a minimum L-10 life of 75,000 hours.


Water Recirculation Pump


The pump(s) shall be a close-coupled, centrifugal type with mechanical seal, installed vertically at the factory to allow free drainage on shut down. _________ horsepower (kW) totally enclosed motor(s) shall be furnished suitable for outdoor service on _________ volts, _________ hertz, and _________ phase.


Heat Transfer Coil


Condensing coil(s) shall be all prime surface steel, encased in a steel framework and hot-dip galvanized after fabrication as a complete assembly. The tubes shall be arranged in a self-spacing, staggered pattern in the direction of airflow for maximum heat transfer efficiency and minimum pressure drop, without the use of additional spacers between the coil tubes. The coil(s) shall be designed with sloping tubes for free drainage of liquid refrigerant and shall be pneumatically tested at 400 psig (2758 kPa), under water.


Water Distribution System


The system shall provide a water flow rate of not less than 6 GPM over each square foot (4 liters per second over each square meter) of unit face area to ensure proper flooding of the coil. The spray header shall be constructed of schedule 40 polyvinyl chloride pipe for corrosion resistance. All spray branches shall be removable for cleaning. The water shall be distributed over the entire coil surface by precision molded ABS spray nozzles (1-1/4” x 5/16” orifice) (3,2 by 0,8 mm) with internal sludge ring to eliminate clogging. Nozzles shall be threaded into spray header to provide easy removal for maintenance.




The eliminators shall be constructed entirely of inert polyvinyl chloride (PVC) in easily handled sections. The eliminator design shall incorporate three changes in air direction to assure complete removal of all entrained moisture from the discharge air stream. Maximum drift rate shall be less than 0.001% of the circulating water rate.




The louvers shall be constructed from polyvinyl chloride (PVC). The louvers shall be mounted in easily removable frames for access to the pan for maintenance. The louvers shall have a minimum of two changes in air direction to prevent splashout and block direct sunlight.




All basin and casing materials shall be constructed of G-235 (Z-600 Europe) heavy gauge mill hot-dip galvanized steel. During fabrication, all panel edges shall be coated with a 95% pure zinc-rich compound for superior protection against corrosion.





Clark Johnson Company, Inc.       2016