Heat transfer in a gas-filled closed enclosure with differentially heated horizontal walls is investigated numerically. One of the side-walls vibrates with specified frequency and amplitude to induce forced convective flows in the enclosure. The vibrating and the stationary sidewalls are considered to be thermally insulated while the two horizontal walls are differentially heated. To simulate the flow field, the full compressible form of the Navier-Stokes equations is considered and solved by a highly accurate flux-corrected transport algorithm. In the numerical model, temperature dependant heat conductivity and viscosity are taken into account. The presence of acoustic streaming is found to have significant effect oil the heat transfer. Also the presence of temperature gradients in the enclosure is found to affect the formation of acoustically induced streaming flows. (c) 2007 Published by Elsevier Ltd.