Abstract: An evaporative cooler according to the invention comprises a one-piece, three-layer pad wrapped around an open-sided cylindrical barrel-like structure. Water is sprayed uniformly over the interior surface of the pad while a centrifugal blower draws air in through the pad from the outside. A novel base design renders it possible to replace the standard square base coolers with the cooler of the present invention. The cooler can be used either with downward or side delivery systems and can easily be adapted to being mounted in a window. The top, base, and barrel are separately fabricated of a non-heat conducting material and are so shaped that they can be nested or stacked for economy of space in storage or shipping.