In this study, a comprehensive discussion of energetic, exergetic and environmental aspects of drying systems is presented. Some theoretical and practical limitations on increased energy and exergy efficiencies and discussions of the relations between energy and exergy, and the environment, along with two illustrative examples are presented. A number of issues relating to energy, exergy and the environment are examined from the drying industry perspectives. It is pointed out that exergy is a suitable technique for furthering the goal of more efficient energy-resource use and it is a key tool to determine the locations, types, and true magnitudes of wastes and losses in the drying systems. It is believed that this paper will provide some guidance to drying industry people in attaining optimum system design and operation. Copyright (C) 2002 John Wiley Sons, Ltd.