A new model is proposed for furnace- and wall-side heat transfer in circulating fluidized beds. It assumes a wall layer of particles whose concentration varies with distance near the heat transfer surface and a thin gas gap adjacent to the wall. The model couples radiation, conduction and convection on the furnace-side to conduction and convection into the coolant on the wall-side. Keller's method is employed to solve the set of non-linear, partial differential equations. The model gives satisfactory predictions of the suspension-to-wall heat transfer coefficient for several sets of published experimental two-dimensional data. (C) 2003 Elsevier Science Ltd. All rights reserved.