The traditional air cooler is technically called a Direct Evaporative Air Cooler. The device is used to cool the air since a long time and the device has been there in very old form since historical times where the Persians used to cool the air by using a device called the wind catcher and this device used to channel wind through pipes which were submerged in water which cooled the air before it was delivered to the targeted area.
The device was a subject of numerous patents in the US in 1906 when various developers and scientists used various different elements or objects to aid in the evaporation of the water and thus attain the cooling of air much faster and efficiently.
This cooler works by taking into consideration, the large amount of heat of vaporisation of water. By passing the warm or hot air through water and evaporating the water the temperature of the air can be drastically reduced and the water vapour along with it also adds on to the cooling effect.
How does an air cooler work?
The air cooler comprises of four main parts, which are:
- A water tank
- A water pump
- An exhaust
- Sides of the cooler covered with water retaining material
- The water tank is used to hold the water which would further be used in the cooling procedure. The tank is just a simple container designed to fit as per the cooler’s size and shape. The water filled inside is also just normal water at room temperature.
- The water pump which are mostly the ones which you could submerge in the tank these days, are a very important tool in cooling. These deliver water to the regions where it has to be evaporated to get the cooling done.
- The exhaust pulls in the air (basically the warm air) by the action of its blades and rotation. This warm air rushes in and this is the air which gets cooled due to losing its heat to the water and making it evaporate.
- The sides of the cooler which are covered with water retaining material are the places where water is evaporated. These are generally a type of grass as used in India or it may also be cool pads made of specially designed foam or cardboard. The pads do the work of holding the water and when the warm air reaches this water the minute droplets of water absorb the heat of the air and just evaporate thus cooling the air in return.
The complete process- much more dynamic
Above mentioned is the work of the various parts but the complete continuous process is much more dynamic. The water pump constantly delivers water from the water tank to the sides of the air cooler containing the water retaining material. This water mostly flows of but there is a little of it retained in form of tiny droplets and when the exhaust is switched on it just sucks in air from all the sides and this sucked in air is pulled from the three sides containing water retentive material where there are droplets of water. This air when it passes through the grass or the cardboard losses its heat to the water droplets which evaporate instantly and are sucked right in along with the air thus making it cool and more humid all at the same time. This air is now pushed out on the opposite side of the exhaust where there is cooling to be done.