Method for Building Model Calibration to Assess Overheating Risk in a Passive House in Summer

Overheating is a major problem that may occur, especially in high-performing buildings. The insulation thickness that is currently installed in passive houses (around 30 cm) may indeed lead to severe overheating problems if this is some mitigated by adequate solar gains control and/or efficient ventilation schemes and strategies. This risk is expressed in percentage and calculated when the indoor temperature is above 25°C. For instance, the acceptable limit for a passive house is set at 5% over a year as defined by the Passive House Platform standard in Belgium(Vandenberghe & VanLoon, 2013). To assess overheating, dynamic simulation is a valuable approach that can be used to calculate the overheating risk and to assess the efficiency of overheating control measures. This paper presents an approach where a detailed simulation model of a passive house was developed (using TRNSYS Type 56), calibrated on the basis of measurements carried out in a typical house in Belgium and then used to compare different overheating mitigation strategies. The accuracy of the simulated model was assessed by calculating statistical indices. When the calibration results have shown a good match between measured and simulated data, the model was used in dynamic simulations to determine the best solution to reduce the risk of overheating in house under study.