David A. Didion, D.Eng., P.E.

David Didion is a retired Fellow of the National Institute of Standards and Technology (NIST). He began the refrigeration engineering phase of his career as a project engineer in the Building and Fire Research Laboratory in 1971. By 1974, he had become the leader of the Thermal Machinery Group and began a 10 year program to develop a series of laboratory test methodologies for seasonal efficiency ratings of various vapor compression cycle machines (e.g., air conditioners and heat pumps). These procedures are in use throughout the manufacturing industry, today. In 1981, he started a research program in zeotropic refrigerant mixtures. This program's modeling and laboratory efforts focused on the interaction between the machinery and their working fluids. This work helped point the way for the world-wide industrial effort to develop the new, chlorine-free, refrigerant mixtures that are compatible with the earth's ozone layer. For this 15 year effort, he has received several honors and awards from the U.S. Department of Commerce, the DuPont Corporation, the Air Conditioning and Refrigeration Institute, the American Society of Mechanical Engineers, and the American Society of Heating, Refrigeration, and Air Conditioning Engineers, the U.K.'s Institute of Refrigeration's 2001 Gold Medal, and the International Institute of Refrigeration's highest honor: the Lorentzen Prize. Throughout this period, he has maintained a teaching career in the graduate engineering evening programs and has been with the University of Maryland ENPM since 1993.

Since his retirement from NIST, in 2002, he has remained active in his engineering practice through consulting with various industries and environmental associations on refrigerants' performance and their compatibility with the environment (i.e, global warming).

ENPM 621 Heat Pump and Refrigeration Systems Design Analysis