Atomisers - evaporative cooling

"Evaporative Cooling" is the process in which water cools the air through evaporation. For this to happen spontaneously, without the contribution of external energy, the water must be atomised in the air as very fine water droplets which, having a lower surface tension than the surrounding air, evaporate into the air.
Why does the air cool down? 
No contribution of external energy is necessary, however, owning to its nature, the water evaporation process requires a certain amount of energy. This energy is removed from the air itself which, in order to absorb the water must release sensible heat, thus lowering its own temperature. Every kilogram of water that evaporates absorbs 0.69 kW of heat from the air. This is how the dual humidification and cooling effect of the air is obtained through the Evaporative Cooling process, which in many air handling applications represent two desired effects.

Energy Saving
The rapid development of evaporative cooling in HVAC applications is surely due to its very low energy impact. If we compare the cost for energy regarding Evaporative Cooling with that of other types of air transformations (e.g. humidification with stream emission or air cooling via chiller), it can be seen that the energy saving is considerable. The only energy required is for water pressurisation, which is sent to the atomiser nozzles by a pump. Consumption is about 4 to 8 W for every l/h of atomised water.

Comments

Popular posts from this blog

CAREL and the dreaded 'NO LINK' Screen!

The Future of HVAC Controls

1tool