Using a numerical model, the effect of the profile of the floor on hydrodynamics and heat exchange in the melting tank of a glass furnace was investigated. The different effect of the length and depth of the tank on formation of convection currents and heat exchange in different parts of the tank was established. Quantitative dependences between the linear dimensions of the deep part of the tank (beyond the sill) and some characteristics of the hydrodynamics and heat exchange in the tank were established. © Springer Science+Business Media, Inc. 2006.