Performances of external walls with different heat capacity: experimental tests in climatic chamber

As the building energy performances must pervasively increase because of the environmental emergency, it becomes more important to correctly appreciate the effects of thermal mass on the heat transfer process actually influencing the thermal energy demand In order to analyze the effectiveness of thermal mass of the building elements in their real service situation, climatic chamber tests have been performed. Four wall types, with the same U-value and different heat capacity, have been tested. Two typical days related to the summer and the winter period have been selected from the Test Reference Year climatic data of Rome, representing the average climatic conditions of Italy. The wall types have been provided with thermocouples placed on the external surfaces and between the walls’ layers, in order to measure the temperature changes through the wall section. Experimental results have been also compared to the ones carried out by simulating the same conditions with a calculation tool based on finite difference method. The same method has been furthermore used to estimate the seasonal maximum heat flows and the results have been compared to the nominal peak loads based on the steady-state approach.