Abstract: An air cooler for cooling air in rooms, such as walk-in storage or cooling rooms includes: a housing, with a bottom, a cover, which can be fastened directly and without spacing to a ceiling of the room to be cooled, and at least one side wall, in which at least one air outlet is arranged; at least one planar heat exchanger, arranged in the housing and laying substantially horizontal; and at least one fan arranged in the housing for sucking in air from the room to be cooled. The air sucked in flows through the planar heat exchanger at least substantially in the vertical direction and is deflected by the fan in the horizontal direction to the air outlet. The fan and the air outlet are arranged above the heat exchanger in the air cooler to avoid dripping of condensed water and accumulation of dust and dirt.