Climatic data including temperature, relative humidity, wind speed and velocity, rainfall and solar radiation have become an integral part of current hygrothermal simulation models. They are implemented mostly in the form of Test Reference Years (TRY) which are constructed by averaging real weather data over several decades. As the more severe and more favorable years are hidden behind this average, the TRYs are suitable primarily for long-term simulations of hygrothermal performance. Critical weather years, on the other hand, are used to simulate the most severe conditions in the studied locality with respect to a particular kind of damage. Therefore, they are mostly applied for short-term analyses only, as it is unlikely for more critical years to occur consecutively. The application of positive weather years is still rare in hygrothermal simulations although the global warming may lead to their more frequent applications in the future.

In this paper, the effect of climatic data selection on simulated moisture and temperature fields in several types of historical building masonries commonly used in Central Europe is analyzed. Four different climatic data sets for the city of Prague are applied, namely the official TRY from the Czech Hydrometeorological Institute, critical and positive weather years generated by a novel approach proposed by the authors, and meteorological data measured by the authors during the last three years. As a typical damage caused by the external environment in Central Europe is due to the freeze/thaw cycles in the external surface layers of building structures, the calculated moisture and temperature fields are assessed using a damage function suitable for the cold regions. The computational results show that the last three years were for all studied building envelopes very positive from the point of view of their possible damage.

DOI: https://doi.org/10.3846/enviro.2017.029