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NIST Technical Note 1735 LoopDA 3.0- Natural Ventilation Design and Analysis Software User Guide



William Dols, Steven Emmerich, Brian Polidoro


LoopDA 3.0 is an update to version 1.0 of the natural ventlation design tool developed by the Natural Institute of Standards and Technology. This software tool can be utilized to determine the size of natural ventilation openings necessary to provide a airflow rates that satisfy design requirements based on minimum ventilation and cooling load requirements. The method employed is based largely upon the Loop Equation Design Method that provides for sizing of openings to utilize driving wind and stack pressures to achieve design airflow rates. This version implements a simple thermal design calculation to assist in determining design tempertures and airflow rates and provides a more streamlined interface to more efficiently implement the design process as compared to the previous version. A simple design example is also provided.
Technical Note (NIST TN) - 1735
Report Number


airflow analysis, building energy' building technology, computer program, design tool, indoor air quality, multizone analysis, natural ventilation


Dols, W. , Emmerich, S. and Polidoro, B. (2012), NIST Technical Note 1735 LoopDA 3.0- Natural Ventilation Design and Analysis Software User Guide, Technical Note (NIST TN), National Institute of Standards and Technology, Gaithersburg, MD, [online], (Accessed May 24, 2024)


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Created February 21, 2012, Updated January 11, 2021