Experiments were performed to investigate the effect that the presence of a gap has on the heat transfer between a heated finned surface and a saturated porous plate with an average pore radius of 200 mu m. There was evidence that the vapour generated beneath the heated surface can escape to the vapour grooves more easily when a gap distance is introduced. This seemed to decrease the vapour penetration into the porous plate. The heat transfer performance of the heated finned surface initially increased as the gap distance was increased from 0 to 500 mu m, but remained relatively unchanged for gap distances of 500-900 mu m. (c) 2006 Elsevier Ltd. All rights reserved.