Waterline – Spring 2018 – Materials Of Construction of Evaporative Coolers & Condensers

Published on 07/20/2018 | by Waterline Admin
As featured in waterline Spring 2018

Materials Of Construction of Evaporative Coolers & Condensers

Colin Brown,
Carter Environmental Engineers

Taking into account the many considerations prospective duty holders have when deciding on the type of evaporative cooling and condenser equipment they should purchase, most will focus on how much will it cost to buy and will it fit the space they have available to site the unit?

The next consideration will be which material of construction will be used for the cooler and how long will the unit be expected to last? This type of equipment can be obtained in galvanised steel, painted or exotic coated mild steel, various grades of stainless steel and GRP all of which will have their merits but also some potential downsides.

All of these materials then have to be matched against the environment the cooler will be sited in, frequency of use, the application they serve and also the quality of the make-up water available. All of these factors should be taken into account when deciding which material of construction should be favoured but also and equally as important is the type of water treatment to be implemented. Indeed this is a consideration that will crop up periodically as water treatment contracts will come up for review and renewal throughout the lifetime of the cooler. However new treatment suppliers may not be as vigilant as to the original materials of construction of the cooler (as well as its internals) and the system possibly focusing more on their own standard water treatment kit and chemicals?

The selection of the shell and base tank material in particular are crucial to maintaining the unit’s hydraulic integrity throughout its working life. There are accounts of coated and galvanised steel coolers where corrosion has occurred which has eventually led to water leaks. This is a critical factor when deciding the material of construction of the unit as repairs to the structure in this scenario are costly and at a cost of downtime incurred to carry out the corrective action.

The overall cocktail of the all of the above will have a direct effect on the control of corrosion, scale and bacteria within the system and the cooler. In addition, and many consider just to be as important, is the ability of the cooler to provide the benefit of its original intention, i.e. to reject heat by evaporative cooling but at the same time remaining to be a safe item of working plant equipment.

Equally as important is the type and materials used for the cooler internal components such as heat transfer pack and drift eliminators as these will be a major consideration for the ongoing efficient operation of the unit. This focuses attention on the required cleaning process to keep these parts in a maximum efficient condition and how and when they and the tower may be cleaned. There are many cases where these internal components have been swapped out without due consideration to maintaining design capacities causing reductions in cooling and drift elimination efficiency as well as becoming problematic with fouling of scale and bacteria.

The “long game” view needs to be taken when deciding on purchasing this type of plant equipment and the material of construction to be used as the initial purchase cost can be deemed a short sighted view when considering the on costs you may be leaving yourself wide open for corrective actions at a later date.

GRP induced draught cooling tower with removable access door

GRP induced draught cooling tower with removable access door

Grime Scene

Grime Scene

Click the gallery image above to view our Grime Scenes!

WMSoc. Training


Specialist training for all aspects of legionella & water treatment.


Product Spotlight

PrimeLab Photometer

The PrimeLab photometer hand-held Bluetooth® device is expandable and portable, developed for ultimate flexibility for use in a range of water systems. With only one light source and the JENCOLOR multi-spectral sensor used exclusively in the PrimeLab, it is possible to measure all water parameters where the water sample is visibly discoloured after addition of a reagent. Key Features of PrimeLab Photometer: The first and only PrimeLab photometer with just 1 LED / 1 JENCOLOR sensor, covering the 400 wavelength (380nm-780nm). More than a 100 different parameters available. Activation of add-on parameters is possible even after purchase. Powerful PC-software and app with free cloud service. Creating reports and dosage recommendations by just a click, using your individual water treatment chemicals.

HuwaSan TR50 Silver Stabilised Hydrogen Peroxide

HuwaSan TR50 is a commercial water disinfectant and biocide designed for shock disinfection or constant dosing. HuwaSan TR50 kills legionella bacteria and in addition removes biofilm. It is safer to use than chlorine as the disinfection breakdown products are oxygen and water. Independent testing shows that HuwaSan TR50 provides a very wide spectrum of biocidal activity against bacteria, viruses, spores, fungi, amoebae (such as amoeba acanthus which can act as a host to legionella bacteria) and algae. Use disinfectants safely. Always read the label and product information before use.

MC1+ Protector

Formulated to prevent wear and tear and the resulting debris, MC1+ stops magnetite and other deposits forming. As it does this, it protects the central heating, keeping the boiler working efficiently and helping to ensure the system lasts for longer.

MM2050 - PT100 Thermometer

Four/three/two wire measurement, Max/min functions, Hold function, Dual display, °C/°F/°A selectable, Simultaneous display of real time and max/min/hold measurement, Self calibrating.

MD610 Photometer

The MD610 gives you a mobile device in a modern design with the analytical features of a laboratory photometer. All important water analysis parameters from A(luminium) to Z(inc) are covered. Combined with the high precision of Lovibond® reagents, a reliable and quick analysis of water samples is guaranteed. Reagent tablets, powder reagents, liquid reagents, or cuvette tests are used depending on the method.

Armitage Shanks Markwik 21


(TB H2a) an integral thermostatic bib mixer tap, single long lever mixer. Single flow fixed horizontal nozzle, sequential operation. Sequential operation ensures both hot and cold supply are purged on each use, long lever gives precise control. Insulated technology keeps the ‘hot’ side of the mixer at a safe surface temperature.

AS Shower chrome

AS Shower chrome

Legionnaires‘ disease is usually spread by the breathing in of water vapour containing Legionella bacteria which is then deposited on the lungs. The bacteria thrives in water temperatures between 25 and 45°C and so showers by their very nature create an ideal environment for the bacteria to spread. The AS SHOWER chrome filter provides reliable and immediate protection against Legionella, removing bacteria at the point of use, allowing users to shower safely.