This paper discusses the drying processes of four different designs of household clothes tumbler dryer using electric power input. The relative advantages and disadvantages and the energy analyses of the dryers are presented. A parametric study was conducted to assess the effects of different variables on energy efficiency and specific moisture extraction rate. It is shown that the conventional tumbler dryer technology can be improved significantly by the use of heat-recovery heat exchangers. Copyright (C) 2001 John Wiley & Sons, Ltd.