In recent decades, more emphasis has been given to produce clean energy from wastes and other renewable sources due to the rise in crude oil price and greenhouse gas emission. Fluidized bed combustors (FBC) are becoming the core of 'clean wastes technology' for power production, owing to their efficient and clean burning of coal and other solid fuels including biomass and other wastes, in an environment friendly manner with reduced pollutants. It is important to understand the mechanism of heat transfer and the effect of operating parameters on the heat transfer process for proper design of fluidized-bed reactors and for control the temperature at desired value. The scope of this paper is reviewing the heat transfer process in different types of fluidized bed combustors as well as the important operating conditions affecting the process. This paper covers both experimental and numerical studies related to the heat transfer process in different types of fluidized bed combustors. (C) 2015 Elsevier Ltd. All rights reserved.