Impact and source of uncertainties in high efficiency building simulation: Some examples

This paper deals with two examples of sources for uncertainties in the simulation of high efficiency buildings. The two sources deal with solar shading and the value of simulation parameters like albedo and initial state. To assess the two sources of uncertainties, simulation results and real measured data of an experimental passive house were used, and the two parameters, often not considered with care during simulation, were varied. The results indicate that a wrong hypothesis on the geometrical model, such as the kind of the shading used, and in the same way an inaccurate estimation of an entry parameter, such as the albedo, may considerably increase the hours of overheating. This demonstrates the large effect that the uncertainties have on the simulation and can create the differences between simulation results and real cases.