A method for the experimental evaluation in situ of the wall conductance

A method for the experimental determination of the in situ building's wall conductance is presented, based on the measurement of wall inside heat flux and inside and outside surface temperatures and on the use of a finite differences calculation code.By applying the method to a test wall, in different periods of time, the conductance values proved to be in agreement with values obtained by the mean progressive method suggested by the EN 12494 pre-regulation. This method has limits in its use since the thermal energy accumulated in the wall has to be negligible compared to the thermal energy passing through the wall during the testing period, whereas the method proposed by the authors can be used more generally and also allows the value of equivalent thermal capacity to be obtained.