ESW4 Closed Circuit Cooler

EVAPCO's LARGEST and most ENERGY EFFICIENT single cell evaporative cooler

The new ESW4 was designed to maximize capacity and optimize energy efficiency in EVAPCO’s single largest closed circuit cooler cell available. Utilizing EVAPCO’s Crosscool Internal Tube Enhancement and the patented elliptical tube Sensi-Coil Technology, the ESW4 provides equal or greater capacity than competitive units that are larger in footprint and higher in fan motor HP. The optimized ESW4 was developed specifically for high tonnage applications such as data centers, industrial plants, and large HVAC applications, where the end user requires the lowest energy consumption on the fewest amount of units, connections and fans. The ESW4 offers the most models and box sizes in the industry and is designed with IBC Compliant Construction, FM Approved Construction and CTI Certified Performance.

ESW4 cooling tower

  • Over 130 models with a wide range of tonnages ( 270 – 670 nominal tons in a single cell)
  • Incredibly energy efficient, maximizing capacity in the smallest footprint and lowest connected horsepower
  • Unique design eliminates need for a discharge hood with dampers and reduces freezing concerns during winter months
  • Patented Sensi-Coil located outside of the airstream uses only sensible cooling, which eliminates water evaporation from the coil, thereby greatly reducing scale build-up on the coil
  • Reduced footprint, excels where space is a concern
  • Ideal for replacing older, inefficient and outdated units
  • Highest IBC (International Building Code) ratings in the industry, available with upgraded construction and 1.5 Importance Factor for critical facilities
  • Available with FM Approved Construction
  • Wide array of fan motor HP options (20 HP to 100 HP)
  • Available with FACTORY-MOUNTED water treatment and EVAPCO’s new Water Saver
  • Independently certified by the Cooling Technology Institute


EVAPCO is proud to be the first to develop a closed circuit cooler with patented Combined Indirect and Direct Cooling technology. The pump is energized, and water circulates up to the water distribution system. The large orifice EvapJet® nozzles evenly distributes water as a thin film over the extended fill surface for maximum cooling efficiency. Simultaneously, the fan system moves large volumes of air through the unit in the opposite direction of the falling water. The air and water contact directly across the fill surface, whereupon a small portion of the spray water evaporates; the warm and saturated air is then discharges from the unit, removing heat from the system. The spray water exits the fill section as a cooled fluid where it is collected by the redistribution basin for even soaking of the full footprint coil. The hot process fluid enters the coil through the bottom coil connection(s). The heat load is rejected to the circulating water that cascades over the coil surface by means of sensible heat transfer


Patented Sensi-Coil Technology
  • An innovation of the already powerful Thermal Pak II® coil
  • Increases total coil surface area by 20%
  • Features EVAPCO’s patented CrossCool™ Internal Tube Enhancement, increasing heat transfer
Drift Eliminators
  • Limits the drift rate to less than 0.001% of the recirculating water rate
  • Reduces water loss during wet operation
  • Constructed of an inert polyvinyl chloride (PVC)
Superior Air Inlet Louver and Screen Design
  • Constructed of an inert polyvinyl chloride (PVC)
  • Two pass design that minimizes splash-out and the potential for algae formation inside the tower
  • Framed in steel in easily removable sections
Pressurized Water Distribution System

EVAPCO's Evapjet® spray nozzle remains clog free while providing even and constant water distribution, providing the industry's best performing non-corrosive, maintenance-free water distribution system.

  • Enclosed and completely protected by the casing panels and drift eliminators
  • Design eliminates the problems of biological growth and clogging that can occur with other system designs
  • Mounted in corrosion-free PVC water distribution pipes that have threaded end caps
  • Provides unparalleled fill coverage
Redistribution Basin
  • Ensures even water loading of the full footprint Sensi-Coil®
  • Enclosed and completely protected by the air inlet louvers
  • Functions as an effective debris screen which block sunlight and prevent debris from entering redistribution system
  • Easily inspected with the removal of the framed air inlet louvers
Stainless Steel Water Touch Basin
  • Available in Type 304 or Type 316 Stainless Steel
  • Includes the entire basin area including the support columns and the louver frames
  • Welded basin seams for leak-free operation
Stainless Steel Casing & Fan Section
  • Available in Type 304 or Type 316 Stainless Steel
  • Includes the entire upper section including fan guard
Stainless Steel Sensi-Coil®

Stainless Steel Coils provide Superior corrosion resistance for hostile environments and is available with the standard EVAPCO lead time! The EVAPCO 304 SST coil option can be manufactured as an ASME coil and is CTI certified.

  • Available in Type 304 or Type 316 Stainless Steel
Sound Sensitive Installations

Available with multiple equipment options to reduce the overall sound generated from the side or top of the unit.

  • Super Low Sound Fan
  • Low Sound Fan
  • Water Silencers
  • Discharge Attenuation
  • Offset Sound Attenuation Walls
FACTORY-MOUNTED Water Treatment Systems

Available with FACTORY-MOUNTED water treatment systems, providing environmentally sensitive alternatives for treating water in evaporative cooled equipment.

  • SmartShield solid chemical water treatment system
  • Pulse-Pure CHEMICAL-FREE water treatment system
NEW Stainless Steel Water Touch Basins Option
  • Available in Type 304 or Type 316 Stainless Steel
  • Includes just the water touch components, the bottom cold water basin and the intermediate redistribution basin above the coil
NEW FM Approved Construction
  • Factory Mutual Approval available for jobs that require FM Global
NEW Upgraded IBC Construction
  • Designed to meet all seismic and wind loads in North America. Also available with 1.5 Importance Factor for critical facilities
Maintenance Accessories

Available with multiple equipment options to aid in the maintenance of the closed circuit cooler.

  • External service platform
  • Basin level platform
  • Sloped ladder
  • Hinged louver access door
  • Motor davit with base
Document Categories
Name File Size Type Language
Betriebs- und Wartungsanleitung Für Rückkühler für geschlossene Kreisläufe und Verdunstungsverflüssiger 13.44 MB O & M German
ESW4 Montage- und Zusammenbauanweisung 3.04 MB Rigging German
ESW4 Rigging bulletin 2.88 MB Rigging English
EVAPCO Closed Circuit Coolers product range flyer 7.5 MB Catalog English
EVAPCO ESW4 bulletin 48.47 MB Catalog English
EVAPCO ESW4 Katalog 7.32 MB Catalog German
Evapco Gamme Refroidisseurs à Circuit Fermé Bulletin 4.47 MB Catalog French
EVAPCO Global Product Catalog 12.88 MB English
EVAPCO Productübersicht Gegenstrom-Verdunstungskühler für geschlossenen Kreislauf 9.17 MB Catalog German
EVAPCO Unità di raffreddamento raffreddatori a Circuito Chiuso in controcorrente 3.82 MB Catalog Italian
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