Evaporative Water Cooling

How Evaporative Cooling Works

Evaporative Cooling is provide by Evaporative heat exchange which takes advantage of the principles of the latent heat of evaporation where tremendous heat is exchanged when water evaporates.

It makes use of the free latent energy in the atmosphere. Compared to air-conditioning which uses mechanical refrigeration, the operating cost of heat evaporative exchanging are 90% less than air conditioning.

Water is brought into the cooler from the mains water supply and is pumped up to the top of the unit using a circulation pump. The water is then dispersed over the Celdek pads using a water distribution system which allows the water to flow continually over the pad.
The pads become saturated, air is drawn through the pads and the water evaporates causing the air to cool. The cool air is then ducted round the building to provide cooling by means of an axial fan.

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Cost Effectiveness

When correctly designed, the system can give an amazing 35kW of air cooling for every 1.5kW of energy consumed.

A working model is installed in the Energy Showroom, showing inlet and outlet temperature readings.

When To Use Evaporative Cooling

Ventilation systems can provide comfort cooling for most of the year. During prolonged periods of high temperatures they are unable to maintain internal temperatures below 25°C. It is at this point that evaporative cooling is brought in. Using Evaporative cooling as an integral part of a balanced ventilation system means that the temperature of a building can be controlled even on the very hottest days.


A lab exercise that demonstrates how evaporation of water lowers the temperature. Also, how surface area affects the rate of evaporation.