Mitchell is a fellow of the American Society of Mechanical Engineers and the American Society of Heating, Refrigerating and Air Conditioning Engineers. In 1987-88 he was on leave, researching building energy management systems at Ecole des Mines, Paris, and the University of Liege, Belgium. One set of projects revolves around the use of energy management systems to monitor and control air conditioning equipment. These studies combine experiments on building equipment with modeling approaches to develop methods for optimal control and fault detection. Neural networks and mechanistic-based models are used to represent equipment performance. Another group of projects involves desiccant air conditioning and enthalpy exchangers. The desiccant is used to dry out air before it enters a building and to reduce the cooling load on the air conditioner. Solar or other heat supplies are used to regenerate the desiccant by driving off the absorbed water. Fundamental heat and mass transfer studies, as well as system analyses, have been carried out. Heat pumps for industrial and commercial applications are also under study. Other projects include heat and mass transfer in food processing, absorption air conditioning, and hot water storage tanks. Professor Mitchell is a member of the Solar Energy Laboratory. His areas of interest are heat transfer and building energy systems. He teaches courses in thermodynamics, heat transfer and HVAC at the graduate and undergraduate levels. He has received departmental and university teaching awards.