Energy performance of passive school buildings – an analysis of building properties and boundary conditions

To evaluate the requirements for passive school buildings, simplified calculation methods based on EN ISO 13790 are used. For these simplified calculations a fixed indoor temperature is used regardless the building properties, the climatic data or the building use data.  Considering the large impact of this temperature on the heating demand, an accurate estimation is important to obtain representative results. This paper analyses the accuracy of the fixed indoor temperature. Multiple dynamic simulations of a reference school building varying the thermal inertia, the insulation qualities, glazing properties and shading are performed to indicate the effect on the indoor temperature. The results show a rather limited impact of the thermal inertia. On the other hand, a more accurate definition of the fixed indoor temperatures based on the function and use of the rooms is important to obtain better results.