He received his BS and MS at Department of Mechanical Eng., Seoul National University in 1987 and 1989, respectively, and PhD at Department of Mechanical Eng, The Ohio State University in 1994. After spending two years at the OSU as a postdoctoral researcher, he joined JST as a special researcher and TUAT, Tokyo, Japan as a visiting professor in 1997. After spending three years at JST and TUAT, he joined the faculty at Kyung Hee University, Korea in 2000, and moved to Korea University as a full professor in 2014. His research focuses on thermal energy systems including absorption heat pumps, heat exchanger design, refrigeration systems, thermal energy storage, CO2 capture using nanoabsorbents and sorption thermal battery. He published more than 200 international papers and more than 250 conference papers. He is now a member of ASHRAE (American Society of Heating, Refrigeration, and Air-Conditioning Engineers), KSME (Korean Society of Mechanical Engineers), IIR (International Institute of Refrigeration), JSHRAE (Japanese Society of Heating, Refrigeration, and Air-Conditioning Engineers) and SAREK (Society of Air-Conditioning and Refrigeration Engineers of Korea). In 2010, his lab. was designated as a National Research Lab. by the Ministry of Science and Technology. In 2015, he received the Asian Academic Award jointly from SAREK/CAR/JSRAE. In 2017, he received the best research award from Korea University. In 2018, he was elected as a fellow of The Korean Academy of Science and Technology. He was also elected as a fellow of National Academy of Engineering of Korea in 2020. He served as a director of BK21 plus center for creative research engineers of convergence mechanical systems, School of Mechanical Engineering, Korea University. He is a former president of SAREK in 2022 and now fellow of SAREK and AUTSE. Now he is a director of Research Center for Plus Energy Building Innovative Technology (ERC) sponsored by Korea Government.