LoopDA 3.0


The Loop equation Design/Analysis software allows you to determine the size of natural ventilation openings necessary to provide airflow rates that satisfy design objectives 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 temperatures and airflow rates. A streamlined graphical interface assists the designer in performing the needed steps of developing the natural ventilation system design including: establishing the global geometry and topology of zones and interconnecting flow paths, establishing design conditions, setting up and solving the representative loop equations based on the “design” form of the airflow components, and analyzing operation under a variety of conditions. LoopDA 3.0 is an update to version 1.0 of the natural ventilation design tool developed by the National Institute of Standards and Technology in 2003.

External Link to Product Page:
United States
Major Capabilities:
Load Calculations, Air Flow Simulation, Other
Building Type:
Commercial, Residential, Multi Family, Industrial
Help And Support:
Last Software Update:
March 13, 2012
A simple design example is provided within the documentation to demonstrate the features of the software.
Mechanical, environmental engineers; building designers; state and Federal agency staff; university faculty; researchers; private consultants.
The GUI is used to draw a schematic representation of a vertical building section including design opening locations and design pressure loops (i.e., the desired path of the natural ventilation airflow through the building section) and input interior design temperatures, ambient design temperature and wind speed, and design airflow rates.
Interactive dialogs displaying loop equation parameters including minimum opening sizes to aid in selecting natural ventilation opening sizes. Simulation results that can be used to verify performance of design. Results are very similar to those provided by CONTAM.
Graphic interface provides means to develop building sections, define pressure/flow loops and develop loop equations.