When water transits from liquid form to air form, the process leads to a substantial drop in the dry air temperature. Evaporative Air Cooler uses the same technology, which is a phase transition or conversion of water from the liquid to the air form. Evaporative cooling uses a considerable amount of water which absorbs the dry hot air and by using the principles of vaporization, decreases the temperature and throws in cool air to the designated area. The efficiency of cooling in the evaporative cooler depends on the wet bulb depression which is nothing but the difference in the temperatures of the dry and the wet bulb. The drop in temperature is significant while a relative gain in the humidity of the air is beneficial in extremely dry atmospheric conditions.