ARBEITSGRUPPE XX Dresden 2010 1 Determination of boundary conditions for passive schools : impact on heating and cooling demand Authors: Barbara Wauman 1,2 , Jeroen Poppe 3 , Stefan Van Loon 3 , Ralf Klein 1 , Kristien Achten 4 , Hilde Breesch 1 , Dirk Saelens 2 1. Catholic University College Ghent, Dept. of Ind. Eng., Sustainable building G. Desmetstraat 1, B-9000 Gent, Belgium 2. Division of Building Physics, Dept. of Civil Eng., K.U.Leuven, Leuven, Belgium Kasteelpark Arenberg 40, bus 2447, B-3001 Leuven (Heverlee), Belgium 3. Passiefhuis-Platform vzw Gitschotellei 138, B-2600 Berchem, Belgium 4. 3E nv Vaartstraat 61, B-1000 Brussel, Belgium 1 Introduction The Passive House standard is originally developed for dwellings in a moderate climate. This standard is extended to school buildings aiming a very low energy consumption and a high thermal comfort. In Flanders (Belgium), as of December 7, 2007, the criteria for Flemish passive school were set forward by the government: annual net heating demand ≤ 15 kWh/(m².a) annual net cooling demand ≤ 15 kWh/(m².a) n 50 ≤ 0,6 air changes per hour maximum E-level = 55 (energy performance as defined by EPB) These criteria show strong resemblances to the performance criteria as set for residential passive buildings. However, the boundary conditions for schools differ strongly from the well known characteristics of residential buildings. In comparison, schools typically have a discontinuous user profile, higher occupancy rates, higher internal heat gains and ventilation flow rates and a large percentage of glass surface. Considering the significant influence of these characteristics on the heating and cooling demand, a set of boundary conditions needs to be defined to guarantee a uniform and objective evaluation of the design of all passive schools in Flanders. Implementing this set of boundary conditions in the existing monthly calculation method PHPP, the impact of these characteristics on the energy demand for heating and cooling is studied. In addition, the results of these calculations are compared to the results of dynamic building simulations in TRNSYS. 2 Methods A list of boundary conditions is developed to evaluate the performance criteria of the Flemish passive schools based on the existing European (EN 12464, EN 13779, EN 15251, EN ISO 7730, EN ISO 13790), Belgian (NBN B 06-002), German (DIN V 18599) and Dutch