The following paper is a translation of “Analyse und Erprobung von Verfahren zur Ermittlung der Raumluftqualität,” authored by Dipl.-Ing. Andreas Jung and Prof. Dr.-Ing M. Zeller at the “Lehrstuhl für Wärmeübertragung und Klimatechnik Rheinisch-Westfälische Technische Hochschule Aachen, Lehrgebiet Klimatechnik.” The German manuscript, completed in 1994, was originally provided to CBE in August 2005 by Richard Craig of Green Building Solutions, LLC, Denver, North Carolina. Many thanks to Richard for making this valuable information available to us. We also want to express our sincere appreciation to Dietmar Goericke of FLT (Forschungsvereinigung für Luft- und Trocknungstechnik) e.V., the sponsor of the research study, and Prof. Manfred Zeller, one of the original authors, for both agreeing to allow the public dissemination of the translated paper. The paper was primarily translated by Wolfgang Lukaschek, formerly a Research Specialist with CBE, with assistance from Lars Junghans, visiting scholar at CBE. CBE has compiled this translation with care and to the best of our abilities, but cannot warrant that the information in the publication is free of errors. We are pleased to make this report available to the U.S. building industry and other interested parties in hopes that it will improve our understanding of the ventilation performance of underfloor air distribution (UFAD) and displacement ventilation (DV) systems.