In recent decades, the refrigeration and air conditioning sciences have been in a state of flux primarily because of the phase-out of ozone-depleting CFC and HCFC refrigerants, and secondarily because of environmental concerns related to the direct global warming impacts of the HFC replacement refrigerants. Due to these concerns, there is significant worldwide interest in using substances that are naturally occurring in the biosphere as refrigerants, which are considered benign to the environment and are termed “natural working fluids.” Surprisingly, many of these substances were already used as refrigerants at the dawn of refrigeration technology in the late 1800s. Thus, when looking at the refrigerants of the future, it is essential to understand which substances have been used in past.
This presentation provides a detailed review of past and present refrigerants and proposes refrigerants and their respective technologies that could be used in the future. An assessment of their characteristics related to the choice of one versus another, and identification of trends set by these choices will be presented.
Dr. Eckhard A. Groll is the Reilly Professor of Mechanical Engineering and also the William E. and Florence E. Perry Head of Mechanical Engineering at Purdue University. He joined Purdue University as an Assistant Professor in 1994 and was promoted to Associate Professor in 2000, to Full Professor in 2005, and to the Reilly Professorship in 2013. He received his diploma in Mechanical Engineering from the University of the Ruhr in Bochum, Germany, in 1989 and a doctorate in Mechanical Engineering from the University of Hannover, Germany, in 1994.