Modelling of large openings.

The subtask 2 of Annex XX (Optimization of Air Flow Patterns Within Buildings) involved a research project called "Air Flows Through Large Openings In Buildings". The scope of this project was to test the range of validity of available algorithms, and where possible to develop new ones. This paper focuses on the new interzonal airflow studies which have been carried out in this frame.

The use of Hall-Effect sensors to measure the opening position of windows, doors, vents and dampers.

Accurate measurement of the positions of windows, skylights, vents, dampers, etc. has always been a problem for researchers. Often open/closed switches are used which do not indicate the degree of opening which has occurred. The use of Hall-Effect sensors to measure such positions was first proposed for monitoring residential passive air inlets.

The use of acoustic intensimetry to size air leakage cracks. Akustische Intensitatsmessung zur Grossenbestimmung von Leckageoffnungen.

The sound intensity technique and reverberant sound excitation have been used for the measurement of sound transmission loss through narrow slits in rigid walls. As predicted by theory, the dimensions of the apertures determine the magnitudes andresonant frequencies of the sound transmission loss curves. It should thus be possible in principle to size air leakage cracksusing the technique described in this paper.

Validation of the Concordia Code.


Air flow through building slits and components.

Pressure models require a good knowledge of the pressure distribution around the building and a precise description of air paths. The hydrodynamic behavior of these connections is usually reduced to an empirical power law Q = K.dP(n) with n equal to 0.5 for a turbulent flow and 1.0 for a laminar one. We present three levels of approach to improve our knowledge of the flow behavior of building components. First, we propose a new light experimental tool to determine the on site flow behavior of building elements.