International Journal of Engineering Research and General Science Volume 2, Issue 6, October-November, 2014 ISSN 2091-2730 995 www.ijergs.org Review of Direct Evaporative Cooling System With Its Applications Suvarna V.Mehere, Krunal P.Mudafale, Dr.Sunil.V.Prayagi MTech Scholar, Dr.Babasaheb Ambedkar College of Engineering & Research Assistant Professor, Dr.Babasaheb Ambedkar College of Engineering & Research Professor, Dr.Babasaheb Ambedkar College of Engineering & Research Nagpur-441110.India E-mail: mehere_016@rediffmail.com Abstract-- Evaporative cooling is an energy efficient and environmentally friendly air conditioning technology. Direct evaporative cooling systems is a technology which involves adiabatic humidification and cooling of air with supplementary heat exchange facilities to lower final air temperature and try to reduce relative humidity. This concept is enhanced in all engineering fields due to its characteristics of zero pollution, energy efficiency, simplicity and good indoor air quality. This cooling effect has been used on various scales from small space cooling to large industrial applications. An extensive literature review has been conducted. The review covers direct evaporative cooling design criteria, applications, advantages and disadvantages. Experimental and theoretical research works on feasibility studies, performance test and optimization as well as heat and mass transfer analysis are reviewed in detail. Keywords: Evaporative cooling, Design, Applications, Performance test, Optimization, Humidity, Air Conditioning INTRODUCTION Evaporative cooling is the process by which the temperature of a substance is reduced due to the cooling effect from the evaporation of water. The conversion of sensible heat to latent heat causes a decrease in the ambient temperature as water is evaporated providing useful cooling. Effective cooling can be accomplished by simply wetting a surface and allowing the water to evaporative. Evaporative cooling occurs when air, that is not too humid, passes over a wet surface; the faster the rate of evaporation the greater the cooling.[1]When considering water evaporating into air, the wet-bulb temperature, as compared to the air’s dry-bulb temperature, is a measure of the potential for evaporative cooling. The greater the difference between the two temperatures, greater the evaporative cooling effect. Evaporative coolers provide cool air by forcing hot dry air over a wetted pad. The water in the pad evaporates, removing heat from the air while adding moisture. When water evaporates it draws energy from its surroundings which produce a considerable cooling effect. In the extreme case of air that is totally saturated with water, no evaporation can take place and no cooling occurs [2]. Fig.1.Schematics of a drip-type DEC.[8]