The influence of air infiltration on the thermal dynamic behavior of buildings.

The thermal dynamic behaviour of buildings is solved by different methods; one of them is based on simulation by means of thermal node models. Computed results of the internal air temperature or the surface temperature are influenced by the used method, by the model for a solved problem situation, and by input values of model elements. The influence of the particular model element can be found by means of a sensitivity analysis. An example shows the calculation of the relative sensitivity for all parameters in a model describing the dependence of the interior air temperature changes on the external air temperature changes for one room of a building. Resultant values demonstrate the importance of conductivities related to the window, i.e. the thermal conductivity and the ventilation conductivity. The outcomes of this research reflect the necessity of using accurate air infiltration rate which influences the outputs obtained from a computer simulation much more than other parameters.