Abstract: A substantially conventional evaporative cooler assembly is provided incorporating a water sump having an overflow and with which a float valve equipped pressurized supply of cool ground water is operatively associated for admitting water into the sump to an operating level slightly below the overflow level. A pump assembly is provided for pumping water from the sump to an evaporative pad through which air flowing through the cooler passes and a mechanical refrigeration unit including a compressor, evaporator coil and condenser coil is operatively associated with the cooler assembly.

Abstract: A humidity reduction duct assembly for attachment over the air inlet of an evaporative cooler having a tray assembly insertable therewith transversely thereacross intermediate the duct inlet and the cooler inlet so that air drawn through the duct passes across and through the tray assembly. The tray assembly is formed of a pair of spaced rigid members having a plurality of foraminous cylinders disposed therebetween in spaced parallel relationship to each other and filled with an air permeable desiccant. The duct removes excessive humidity from the ambient air and enhances the efficiency of the evaporative cooler.