They are generally found in the drier climates of the western and southwestern United States. The box shaped evaporative cooler cabinets are constructed of plastic or metal and are often installed on top of house roofs. A water cooler pump such as the Dial D5500 model is located inside the cooler cabinet. The pump functions to draw supplied water from the reservoir at the bottom of the cabinet to the distribution system at the top. Water then saturates the cooling pads located vertically inside the vented cabinet.
Outside air is cooled and humidified as it is pulled through the pads by the cabinet blower.
The blower then forces the moist cool air into the house. Because of the corrosive nature of the cooler environment, economy pumps such as the D5500 reportedly last only one season. However, some of these pumps are still in service. Consumers who identify this blue cooler pump should stop using their evaporative coolers until the pump is replaced. Dial will replace any 1990 blue D5500 cooler pump free of charge with a new 1991 red and white D5500 pump or a 1992 red and white D5000 pump.