William Bahnfleth is Professor of Architectural Engineering at the Pennsylvania State University, where he teaches classes in fundamentals and design of heating, ventilation and air-conditioning systems and conducts research on a variety of areas, principally energy efficient control of bioaerosols. He is the author or coauthor of nearly 200 scientific and technical publications. He has held prior positions as a senior consultant for ZBA, Inc. and as a principal investigator for the US Army Construction Engineering Research Laboratory. He holds BS, MS, and PhD degrees in Mechanical Engineering from the University of Illinois at Urbana-Champaign and is a distinguished alumnus of the Department of Mechanical Science and Engineering. Dr. Bahnfleth is a Registered Professional Engineer and a fellow of the American Society of Heating, Refrigerating, and Air-Conditioning Engineers (ASHRAE), the American Society of Mechanical Engineers (ASME), and the International Society for Indoor Air Quality and Climate (ISIAQ). He is active in ASHRAE, having served as its President in 2013-2014. From 2020-2022, he chaired the ASHRAE Epidemic Task Force in its efforts to develop guidance to reduce transmission of Covid-19, garnering an ASHRAE Presidential Certificate of Honor and a letter of commendation from the US Environmental Protection Agency. He is the recipient of numerous awards from ASHRAE, including the Bill and Louise Holladay Distinguished Fellow Award and the F. Paul Anderson Award, ASHRAE's highest honor. The Penn State Engineering Alumni Association has awarded him its World Class Engineering Faculty Award and he received an "exemplary designation" for faculty outreach for his Covid-19 related service activities. Among his other service activities, Dr. Bahnfleth has participated in multiple National Academies consensus committees, as an advisor to Alfred P. Sloan Foundation indoor air quality programs, and as a member of the Clean Air Act Advisory Committee.