Determination of boundary conditions for passive schools: impact on net energy demand for heating and cooling

In Flanders (Belgium), the government decided to subsidize the additional costs of 24 pas-sive school buildings as pilot projects. Performance requirements were set, showing strong correspondence to the requirements for passive houses. However, the characteristics of school buildings differ strongly from those of residential buildings. Furthermore, they are affected by the use and typology of schools. Depending on regional customs and regulations, the boundary conditions may even differ between regions or countries. To evaluate the requirements set for passive school buildings, simplified calculation methods for assess-ment of the annual heating and cooling based on EN ISO 13790 are used. As these calculations are strongly affected by the boundary conditions, they can only offer representative results for evaluation of the perfor-mance level of the design if the boundary conditions are defined properly. Therefore, to reassure objective and unambiguous evaluation, a large variety of parameters is defined specifically for Flemish school build-ings. The paper gives an overview of these boundary conditions and clearly amplifies the effects of these properties on the energy demand for heating and cooling. Therefore, a comparison is made between the cur-rently applied boundary conditions and the newly defined properties implemented in the existing monthly cal-culation methods PHPP and EPB. In addition, a comparison is made between the results of both calculation methods. Although based on the same standard EN ISO 13790, important differences between the results for cooling and heating demand are concluded. Therefore, it is not only important to define exact boundary con-ditions, but to critically evaluate existing calculation methods used for performance evaluations and certifica-tion procedures.

ISBN:978-83-7283-367-9

Publication year:2010

BOF-keylabel:yes

IOF-keylabel:yes

Authors from:Private, Higher Education

Accessibility:Open