In air-conditioning systems, conditioned warm/cold air is supplied to the room depending upon winter/summer. This air should be properly distributed into the room so that there are neither draft conditions nor stagnant zones. In this investigation air circulation and temperature distribution in a room have been studied for a particular location of air inlet and outlet on opposite walls. Two-dimensional, steady, laminar, incompressible flow has been considered. Navier-Stokes equation and energy equations in two-dimensional rectangular Cartesian co-ordinates have been numerically solved using control volume method. Boussinesq's approximation has been used for buoyancy force. The cold primary air enters the room near the ceiling. The flow attaches with the ceiling due to Coanda effect. It moves along the ceiling and comes down along the opposite wall to go out for small values of Gr. For larger values of Gr, it moves along the ceiling for some distance and then stoops downwards, attaches with the floor and then goes out. As Reynolds number increases, the point of attachment on floor moves away from the inlet. As the buoyancy increases the flow attaches with floor earlier. Two circulation zones are observed due to entrainment. The intensity of circulation increases with Reynolds number and Grashof number and temperature becomes more uniform. (c) 2006 Published by Elsevier B.V.