A mechanistic model to evaluate heat transfer rates between a bubbling fluidized bed and immersed surfaces will be analysed in this work. The model incorporates the three mechanisms contributing to heat transfer: heat conduction, radiation and gas convection. The model relies on effective parameters defined for two zones in which a dense phase packet in contact with the heat exchanging surface is divided: the layer of particles adjacent to the immersed surface wall and pseudo-homogeneous zone accounting for the rest of the dense phase packet. Comparison of model predictions with experimental data from the literature is carried out to validate model formulation and to evaluate model parameters. Model predictions agree well with most of the experimental data involving a wide range of operating conditions.