Buildings.Airflow.Multizone.UsersGuide

The models can be used to compute the air flow between different rooms and between a room and the exterior environment. In multizone airflow models, typically each room volume is assumed to be completely mixed. The driving force for the air flow are pressure differences that can be induced, e.g., by

• flow imbalance of the HVAC system,
• density difference across large openings such as doors or open windows,
• stack effects in high rise buildings, and
• wind pressure on the building facade.

Wind pressure coefficients for different building configurations can be found in Costola et al. (2009).

The models in this package are as described in Wetter (2005), except for some changes that have been done when migrating them to Modelica 3.1, which led to a simpler implementation based on the stream functions.

Acknowledgements

We would like to thank the United Technologies Research Center for contributing this package to the Buildings library.

References

D. Costola, B. Blocken and J.L.M. Hensen. Overview of pressure coefficient data in building energy simulation and airflow network programs. Building and Environment. Vol. 44(10): 2027-2036. 2009.

Michael Wetter. Multizone Airflow Model in Modelica. Proc. of the 5th International Modelica Conference, p. 431-440. Vienna, Austria, September 2006.