How does Mist Cooling work?

Installation of a COLDMIST mist cooling system permits the atomization of water to micro droplets around 6-8 microns in size. These droplets are light in weight and are easily flash evaporated . Light droplets remain airborne for longer periods of time before succumbing to natural gravity forces and falling to the ground. When these droplets come into contact with hot air they flash evaporate and - in so doing - effectively consume/remove heat in the air. The ambient temperature is thereby reduced by 10-12 degrees.

Repeated millions of times a second, this flash evaporation process results in large amounts of heat energy consumption thus removing  heat from the air. Our system operates by removing heat from the air rather than cooling the air. Whilst the end result is the same the methodology is different to standard air conditioning. Once the flash evaporation process has completed, it is important to ensure that the evaporated water molecules are removed from the area allowing for fresh water micro droplets to be replaced thus permitting the process to be repeated. Failure to remove the evaporated molecules whilst continuing to introduce new water droplets will result in humidity build- up and wetting. The misting equipment essential to micro atomize mains water includes high pressure pumps and correctly sized misting nozzles.

In misting systems using fixed mist lines , the replacement process of evaporated molecules is achieved by ensuring that the location being misted has adequate ventilation. This can be in the form of natural breezes or artificial air flow as created by electric fans. There will always be a degree of natural air movement as hot and cool air interact with each other and as the colder air, which is heavier than hot air, moves downwards.  Generally, misting systems work best where lower humidity is present with efficiency decreasing as humidity increases. To overcome high humidity or to cater for situations where specific targeted areas need to be cooled, fitting misting rings to the front of electric fans is the solution. The advantage here is the added convective cooling ( wind chill factor ) that is created. Misting rings can easily be retro-fitted to existing fans by attaching them to the front of the fan guard using cable ties or similar fixing methods.

Guidelines:

Remember that the principle of mist cooling is the removal of heat from the air when heat comes into contact with atomized water droplets. Consequently it follows that wherever you distribute your atomized water droplets is where the heat exchange/cooling will take place. Fans need to mounted 2.5 to 3m above ground level.

The area cooled will be equal to the area reached by the air generated from the fan. This is clearly visible when the system is turned on. Setting the fan to oscillation will increase coverage by the mist. The average, approximately 700mm diameter personnel cooling fan, will be fitted with a 4 or 5 nozzle Mist ring. ColdMist's smaller  high pressure Pump/Controller can drive a maximum of 26 nozzles enabling you to operate 5 or 6 Fans. For larger installations, Pump / Controllers with increased capacities - capable of driving up to 220 nozzles - can be fitted.

The Fan and Misting Ring method is preferred when Evaporative Spot Cooling - rather than Blanket Cooling of a large area - is required.

FAQs

  • How does Mist Cooling work? +

    Installation of a COLDMIST mist cooling system permits the atomization of water to micro droplets around 6-8 microns in size. Read More
  • Will the misting system cause wetting? +

    The simple answer is NO. Correctly installed and operated a mist cooling system will not cause wetting. Read More
  • Do I have to use a pump or can I operate my mist cooling system directly from mains water? +

    A misting system without a high pressure pump is a micro IRRIGATION system—good for plants , bad for cooling !  The HIGH PRESSURE Read More
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