Adaption of the passive house concept in northern Sweden - a case study of performance

This study analyzes the performance of a case study of low energy house built in Östersund (lat. 63°N), Sweden. The building is a semi detached house for two families, with each apartment having a floor space of 160 m divided on two floors. The building was constructed during 2010 according to the Swedish passive house principles with design that meet the requirements for Swedish passive houses as defined by the Forum for energy efficiency buildings (FEBY) and the Swedish center for zero energy houses (SCNH). The house is connected to the district heating network, which is the main heat source for domestic water heating, floor heating in the bathroom and water based pre‐heater coil in the ventilation system. Additionally, a wood stove is installed in the living room for thermal comfort and convenience of the residents. The two identical residential units in the building were inhabited in the end of 2010 by families with different characteristics; a family with two young children in one unit and a middle aged couple in the other. A one year energy measurement campaign started in May 2012 for both of the residential units. The measurements started after a period of adjustments of the building energy system and include space and domestic water heating (separate measurements), household electricity, the amount of fuel wood used in the stove, and indoor thermal conditions. The results show that it is possible to build passive houses in the Northern regions of Sweden. The specific final energy demand of the case study was 23% lower than the Swedish FEBY‐requirements. Differences were found between the monitored and calculated specific final energy demand. These differences depend to a large extant on the occupants’ behavior and household characteristics. The final energy demand for heating and domestic water heating found to vary significantly between the two households.