The Importance of Evaporative Cooler Water Quality
Evaporative cooler water quality is easily overlooked in the process of designing an installation of evaporative coolers, yet it is very important. Pure clean fresh water is best for evaporative coolers. For most applications where their water is from a mains source the water quality should not be an issue, however where water is taken from other sources such as bore holes or springs, a bit more care need to be taken.
Water held in an evaporative cooler and circulated via the pump over the media panels can build up concentration of mineral and salts. This is because although there is a constant supply of water into the cooler only pure H2O evaporates from the panels onto the cooled air, This means that trace minerals and salts over time accumulate and can damage the internal components and indeed the panels. Left untreated mineral deposits can form scale in the inside of the reservoir and on other components and can restrict the airflow through the panels.
Water inlet float valve, overflow port and purge arrangement
Met Mann coolers overcome this problem by having a system of continuous purge. The system enables not only the salts and minerals to be flushed through to the drain but also ensures that dusts and bacteria that are trapped by the water flowing through the media panels do not accumulate. The continuous purge system in Met Mann evaporative coolers ensures that the inside is kept clean and functional. When we supply a static evaporative cooler we need to know the pH of the supply water, as well as the concentration of HCO3 and Ca2 and with these values we can calculate the purge constant for the system and ensure it is correctly set on commissioning.
The added feature of the continuous drainage system is that it is adjustable, and would typically be set as part of the commissioning procedure, to a through flow rate that is suited to the water quality. This means that the lower the quality of the water supplying the evaporative cooler, the higher the required drainage rate to remove the contaminants.
UV water purification system
biocide dosing pump
The water should be biologically pure as well. Although Met Mann evaporative coolers are very safe in use and operate in a way that prevents the proliferation of legionella, it is sensible to take precautions to prevent the proliferation of other biological contaminants in the water. For this reason we offer both UV water purification systems to treat the water in the cooler and also dosing systems for administering water purification solution.