NISTIR 6964 Results from Simulation and Laboratory Testing of Air Handling Unit and Variable Air Volume Box Diagnostic Tools Natascha S. Castro Jeffrey Schein Cheol Park Michael A. Galler Steven T. Bushby U.S. DEPARTMENT OF COMMERCE National Institute of Standards and Technology Building Environment Division Building and Fire Research Laboratory Gaithersburg, MD 20899-8631 John M. House Iowa Energy Center Ames, IA