John Varley, P.E., LEED AP BDC, HBDP is an associate principal at HED in Chicago and has been a professional in the building sciences industry for more than 30 years. He is a past chair of ASHRAE Technical Committee 9.10 Laboratory Systems, TC 9.11 Clean Spaces, and received the Distinguished Service Award from ASHRAE. He has been published in the ASHRAE Journal, ASHRAE Transactions, The International Journal of HVAC&R Research, and Engineered Systems. Varley is a registered professional engineer in Ohio, Michigan, Georgia, Florida, Illinois, Minnesota, and Wisconsin. He holds a B.S. in mechanical engineering from the University of Akron and an M.S. in chemical engineering from Cleveland State University.