Evaporative Cooling Salinity Control

Why bleed off?

Only pure water evaporates from the filter pads leaving behind any salts, dissolved solids and particles filtered from the air. The sequence below shows how these gradually concentrate as the cooler is replenished with water.

First Fill	Evaporate	Second Fill	Evaporate

If this build-up was allowed to continue then scale would form and sediment would build up.

Water is at the heart of any evaporative cooler. Its control is vital in maintaining an efficient and hygienic cooler. The EcoCooling range of coolers has the most sophisticated process controls available based on very simple engineering.

The water control system is based on four level probes. As the water rises the water inlet valves are turned on and off to maintain the working level between the Low Level and the High Level. The process control system counts the number of times the sump is replenished between LL and HL. From this it calculates, according to the water quality, when to drain the sump as the water approaches the scaling point. The factory default bleed rate is 30% which is suitable for most mains water. This bleed rate can be changed from 18% to 46% to accommodate other water qualities.