Abstract: An air supply for a device for conditioning rooms comprises a double-walled air blower (10) which extends along the lower portion of at least one outer wall (2,4,6) of the room, the inner wall (22) of the air blower defining a longitudinal duct (18) adjacent the room wall. This duct communicates with an apparatus for air conditioning and is in its upwardly turned side (22) provided with openings for exhaust of air into the room. The outer wall of the double-walled air blower, which faces the interior of the room, defines a space (20) with the inner wall of the air blower, which space is open towards the room and communicates with the exhaust openings (24). The air blower (10) is designed to form a base in the room at the lower portion of the wall and further designed to produce co-ejection of room air through the space (20) when exhausting air through the exhaust openings.