Abstract: An improved evaporative cooler is disclosed which includes a highly efficient air transfer system and an effective system for closing off the conditioned space from the ambient when the cooler is out of service. The air transfer system includes a vertically oriented shroud having an air intake region situated at the top, an air exhaust region situated at the bottom and an imperforate intermediate region continuously connecting the intake and exhaust regions. The intermediate region diverges smoothly downwardly, and a horizontally disposed fan is centrally disposed at the shroud bottom. The efficient intake of air into the shroud is promoted by a circumferential lip extending completely around the air intake region, the lip curling smoothly inwardly and arcuately. Effective seasonal sealing is achieved with an optional shroud sealing system supported on the shroud intake region.