HUMIDIN evaporative coolers are available with two types i.e. Single Skin and Double Skin.The corner sheet metal is of cast iron with no insulation while double skin has PVC with Puf insulation that´s CFC free. Working Principle. A natural and energy-efficient means of cooling can be provided by evaporating water into air, specially, in low-humidity areas. This very principal is used in the evaporative coolers, i.e. cooling outdoor air by passing it over water-saturated pads, causing the water to evaporate into it. The 15��40�F-cooler air is then directed into the required space, and pushes warmer air out through the given vents. While its operation, vents are opened part way to allow warm indoor air to escape as it is replaced by cooled air. I contrast to central air conditioning systems that recirculate the same air; evaporative coolers provide a steady stream of fresh air into the required space. Evaporative coolers cost about one-half as much to install as central air conditioners and use about one-quarter as much energy. DISCERNIBLE FEATURES: Panels designed by special software Standard pre-filters & proper accessibility Cellulose pads of imported origin Water tanks with anti-corrosive coatings 'AMCA' certified 'HUMIDIN' made fans Standard optional accessories APPLICATIONS All the low humidity areas can undoubtedly be served more efficiently by 'Evaporative Coolers'.