The American-made N28W evaporative window is an economical unit that provides high performance, easy installation, and low maintenance. Evaporative Coolers are intended for use in dry, arid climates. They can lower indoor temperatures by as much as 15-20° F. Evaporative coolers have low installation/maintenance costs. use 75% less electricity. no ozone-damaging refrigerants. The water-saturated pads act as a type of filter, removing dust and allergens from the air.