Let us first see what the working of the evaporative cooler is. The evaporative water coolers circulate the water across the pads or other things. For evaporating the water in order to reduce the sensible heat from the air, air is blown through the pads. There are many reasons for this. First is when hard water is build up on the cooling pads, it reduces the air flow inside the structure that is being cooled. It also blocks the water pump as well as water distributor and direct it towards surplus down time.
In most of the watercoolers, a cleaning supply pump is used and this will replace the water after every six to eight hours. Another working of it is it will keep the wet section of the water cooler clean but this is not always the case and one should take care of the hygiene. So, water cooler supplier recommend always cleaning the pumps and draining them by some soft bristle brush. This will keep the circulation pumps run at their top capacity.
The second reason is that the moving parts are needed to be adjusted and greased with fine oil in order to prevent premature damage. Thus this will shorten the life expectancy of the water cooler. Always do this at least twice a year.
This is the working of the evaporative water coolers and this is the reason many people prefer it on plumbed in water coolers.
