New Towers

Series ES/ESP Cooling Tower

Series ES/ESP Cooling Tower


The FM Approved Series ES and ESP evolved from the proven EvapTech Series EC product line. These products share high quality fire-retardant fiberglass pultrusions with proven structural integrity and a design methodology confirmed by FM Approvals Standard Class 4930 for resistance to the most extreme natural hazards.

EvapTech is a participating manufacturer to CTI Standard STD-202 (Publication of Test Results). The EC, ES and ESP product lines share the same functional heat transfer and drift eliminator component designs, although the ESP component materials are customized. The use of these heat transfer and eliminator designs assures owners reliable thermal performance and low drift rates.

Series ESP

  • Unique premium product Line intended for both single and multi-cell FM Approved applications.
  • Eliminates the FM requirement for any redundant thermal capacity.
  • Provides a greater degree of protection from fire and natural hazards to reduce the recovery time and cost when compared with other approved products.
  • Franklin Fill™ and Franklin Eliminators™ are made of custom formulated PVC with a limited combustibility rating. The self-extinguishing characteristics of these materials create a charring effect to choke off airflow and inhibit the spread of fire – If a fire cannot spread; it is by definition contained.
  • ESP incorporates the hardened SafeWall™ custom fiberglass casing technology to resist natural hazards.

Series ES

  • Intended for multi-cell FM Approved applications, typically when four or more cells are required.
  • Comparable fire protection to towers previously approved by older FM protocols requiring only containment of a fire.
  • Employs FireStop™ structural concrete panel technology to contain a fire within the cell of origin by preventing the fire from spreading over, under, around or through the cell walls and partitions to adjacent cells.
  • Incorporates the hardened SafeWall™ custom fiberglass casing technology.

Key Advantages of Series ES & ESP

  • Reliability of Operations – Minimal loss of performance and interruption to operations.
  • Hardened to Survive - SafeWall™ technology resists damage and compromised thermal performance resulting from airborne debris and wind pressures created by severe storms and hurricanes. The durability that results will improve operation, maintenance, and reduce repair costs for the life of the product.
  • Cost Effective – The Series ES & ESP products are cost comparable to towers with fire protection systems.
  • Customizable Fill Components – A variety of high performance low-fouling fills with different sheet thicknesses for standard and extended service life.
  • Low Drift Rates – The best available control technology (BACT) for drift rates as low as 0.0005% is standard.
  • Air Inlet Treatments – The Series ES & ESP products can be customized for any application with a variety of air inlet treatments including no louvers, wide-spaced louvers, or cellular PVC louvers.
  • Product Quality is a Given – Quality audits of all combustible components by FM Approvals assures the same FM Approved product is provided for every project.
  • Avoid Thermal Redundancy – Extra or over-sized cells are not required.

Download the Series ES / ESP brochure here for more information. For even more personal service, especially about how we can meet your specific cooling tower requirements, contact EvapTech at

... for more information contact 


FM Approved field erected counterflow fiberglass cooling towers have historically been preferred or required by customers insured by FM Global. Many customers, including those not insured by FM Global, recognize the critical nature of their processes and the benenfits of third-party certified loss prevention products including evaporative water cooling towers.

Download our Primer and FAQ for more information on this vitally important topic. Click here.

In addition, you may want to click here and register for free on the FM Approvals, Approval Guide website. You will discover quite a lot of relevant infomation there.

Typical Series ES/ESP Comparison Cross Section

Counterflow Tower Arrangement

A variety of counterflow tower layouts are available to meet the unique plot requirements of each individual project.  An in-line tower is the standard layout for efficiency reasons, but parallel in-line and back-to-back are also options when the plot plan requires a different approach.  Click on the layouts below for more information, and contact EvapTech at for guidance on meeting the challenges of your project layout.

In-Line Arrangement

The most efficient and cost effective approach to tower design. Constructing the tower in a linear fashion provides the arrangement with the least parasitic power consumption, including reduced fan energy consumption and lowest pumping head.  By providing efficient entering air access, the tower height  and cost is minimized. 

Parallel In-line Arrangement

When  dictated by site constraints that would not allow a long single tower in-line arrangement, why not consider splitting the tower into two or more units arranged in a parallel in-line configuration. Although the overall tower footprint is wider than that made possible by utilizing a back-to-back configuration, consider the advantages:

  • Substantially reduced tower pumping head by splitting the air inlet area between two tower faces
  • Substantially reduced tower cost made possible by a reduced tower height and gained efficiency
  • Reduced fan energy by regaining lost efficiency with two air inlets
  • Reduced installed length by utilizing the area between towers for pump pits, MCC, piping, and access provisions
  • More reliable thermal capacity by cutting the air draw through the falling water in half
  • Easier maintenance and staged operation by providing the facility with easily isolated towers
Back-to-Back Arrangement

When  dictated by site constraints, a back-to-back tower configuration can fit within site limitations not possible with an in-line arrangement. However, reduced thermal efficiency and added cost result from a cooling tower arranged in a back-to-back configuration with both increased fan energy and substantially increased pumping head.

Counterflow Tower Structure

The vast majority of new counterflow towers are constructed of fire retardant fiberglass because of its high strength and fire/corrosion resistive properties.  Fire retardant fiberglass is especially appealing when high strength and resistance to flame propagation are important.

These two properties ensure that an FRP structure can meet the challenges presented by natural hazards and answer the call from FM Global to reduce interuption of operations caused by these events.

EvapTech's Newton, IL facility manufactures these pultruded parts, allowing  superior quality and lead time control.  Learn more about EvapTech manufacturing here.  Treated wood and concrete structures are also available materials.  Click on the materials below for more information and contact EvapTech for guidance on the best material for your particular application at


Series ES: Pultruded Fiberglass

The standard of the industry and the material demanded by most new cooling tower purchasers. But not all FRP frames are created equal, in design or material quality.

Pultruded FRP 's strength is unidirectional and our superior designs utilize line-of-action force distribution of wind and seismic loads.

EvapTech is the only cooling tower company to manufacture our own pultrusions in our state of the art factory in Newton, Illinois. This enables EvapTech to design component strength properties to match the requirements of our frame layout, all of which is verified by rigorous component physical testing activities.

Customers should demand quality fiberglass components that are made in the U.S.A.

Counterflow Tower Fill

The Series ES and Series ESP utilize the same proven high efficiency reduced fouling vertically offset flute fill as the EC Series product line, but with a twist. In addition to now being FM Approved in this product arrangement, EvapTech introduces Franklin Fill™ custom PVC fill products. The fill, with a flame spread rating of Zero when tested in accordance the ASTM E-84, has revolutionized the meaning of an FM Approved fiberglass cooling tower.

Franklin™ fill is at the heart of the Series ESP product line that results in the first ever PVC filled fiberglass cooling tower to achieve FM Approval in the coveted single-cell category. This breakthrough technology resists the propagation of flame and allows each cell of the tower to maintain the required 75% of design capacity in the cell of origin. Eliminating the potential need for thermal redundancy and greatly reducing the exposure to loss due to fire.

Click on the fills listed below for more information and contact EvapTech for guidance on selecting the correct fill for your application at .

Counterflow Tower Drift Eliminators

EvapTech's DriAir80 drift eliminators represent the BACT (Best Available Control Technology) in cooling tower drift eliminators, limiting drift rates to as low as 0.0005%.  

In addition to the standard PVC used in the Series ES product line, Franklin™ custom PVC drift eliminators combine with Franklin™ fill products to revolutionize FM Approved cooling towers in the Series ESP product line. No longer do you have to settle for simply containing the spread of fire, the E-84 zero flame spread rating results in a product that will continue to operate immediately following a fire event.

Click on the eliminator models below for more information on EvapTech's drift eliminators, or contact

Counterflow Tower Water Distribution

Evenly distributed water is key to a cooling tower's thermal performance.  EvapTech engineers the distribution system to meet the requirements of each application for maximum thermal performance with minimized operating pump head.  Click on the links below and contact EvapTech at for more information on the water distribution systems and custom options.


Cooling Tower Mechanical Equipment

The ability of a mechanical draft cooling tower to efficiently and reliably transfer waste heat is entirely dependent upon the reliability of the mechanical equipment package. Therefore EvapTech provides fans, gearboxes, driveshafts and motors from a select group of equipment suppliers specializing in the supply of top quality mechanical components to assure exceptional reliability of their thermal performance.  Read about EvapTech's mechanical equipment support system below and contact EvapTech at for more information on mechanical equipment.


Mechanical Equipment Support

Equally as important as the mechanical component selection,  equipment support design utilizing a properly sized round torque tube to effectively restrain rotational dynamic loads is essential to assuring the longevity of these costly and critical tower components. The devil is in the details and the design details of support bracing and its attachment to the tower structure will determine if the support effectively restrains rotational and vibration loads. 

The EvapTech Edge:

Support Sizing - EvapTech properly sizes the torque tube for the fan diameter and applied horsepower - Flexing of undersized supports is a common cause of reduced gear, motor, and driveshaft operating life.

Support Design - Equipment mounting plates braced against movement in all directions - simple bent plates welded to the tube do not provide the rigidity required by the driveshaft and will ultimately lead to failure of the shaft and gear/motor bearings.

Positive Positioning - Jack bolts are provided for ease of alignment and assure properly secured motor and gear placement - do not rely upon a simple spiral pin to maintain alignment during numerous start/stop cycles.

Structural Attachment - Torque tube loading must be applied directly to the tower's vertical column framing  with steel plates bolted directly from the support to vertical framing members - never allow horizontal framing members, plastic gromments, or hollow leg fan deck panels sandwiched between the support and tower framing to be used to transmit loads.

Vibration Bracing - Diagonal bracing immediately below the supports transmits and spreads loads into the  surrounding structure - Both pultruded fiberglass and timber are unidirectional strength materials, anticipating that vibration loading will be adequately restrained by moment loading of these members will result in a substantially reduced life cycle of mechanical components.

Counterflow Tower Upgrades

In order to meet our clients' custom needs and requirements, EvapTech offers a wide variety of tower upgrades designed to improve safety, matinenance access and aesthetics.  Click on the options below to learn more and contact EvapTech at for more information.

SafeLift™ Equipment Handling Packages

Whether you want to lift tools, oil, or mechanical equipment components from grade to the fan deck, EvapTech has an option available to meet the need safely.

SafeRoute™ Cable Tray Supports

Eliminate trip hazards and fan deck clutter with EvapTech supplied and installed externally mounted cable tray supports.


Retained landings and individual stair treads to avoid potentially hazardous winter grip conditions are just two of the features the separate EvapTech's stairway design from the rest.


Standard FRP ladders in safety yellow enhance safety for the life of the product by assuring long term durability and improved grip over less costly HDG steel. Options are available for intermediate landings and landings at the collection basin level to improve worker safety and save project costs.

Plenum Area Walkways

With this upgrade access to the mechanical equipment is quick, convenient, and without the need to remove the fan cylinder access door. When installed in combination with the EvapPad™ gear access platform this system provides exceptional mechanical access for routine inspection and maintenance.

Removable Aluminum Catwalk

Providing safe, convenient, and portable fan deck access to the mechanical equipment. The removable catwalk safely transports workers to either the OSHA tie-off location at the gear or to the optional EvapPad™ access platform to perform routine inspection and maintenance of mechanical components.

EvapPad™ Access Platform

Access via a removable aluminum catwalk or an FRP walkway, the EvapPad access platform provides unsurpassed access to the heart of the most critical mechanical draft cooling tower component, its gear reduction unit.

WST™ Cellular Inlet Louvers

EvapTech’s Water and Sight Tight cellular inlet louvers offer exceptional water containment while blocking sunlight from reaching the circulating water to help reduced chemical consumption. In addition to being easily removable without tools, WST louvers can be fitted with framed access doors to ease routine inspection. Commonly provided on HVAC projects, WST louvers offer owners a highly desirable clean aesthetic appearance.

Grade Piping, Valves, Inlet Risers, Expansion Joints, Sway Braces, and Supports

EvapTech designers can properly design and supply above grade plant piping to fit your project needs in state of the art fiberglass construction. Consider single point connection of your next cooling tower.

Grade header, risers, riser swaybraces, isolation valves, and expansion joint options shown.

Wide Spaced Louvers

Louvers constructed of wide spaced FRP panels and supported from either timber or FRP members is a common option to control water splashout and reducde basin footprint. Insist upon reinforced leading and trailing edges when gthe potential for exposure to freezing is a concern.

Collection Basin Bypass Piping

Winter operation requires direct bypass into the collection basin? Allow EvapTech to design and install the correct piping to interface with your system and the cooling tower structure.

Special Basin Requirements

Extending onto an existing basin? Steeply sloped pump pit transition? Integral mud trench? EvapTech will design the cooling tower structure to interface with your special needs to reduce project basin costs.

Enclosed Stairway

Take safety to an elevated level by upgrading to an enclosed stairway. For those in freezing climates this can be a critical maintenance upgrade.