Indoor climate systems in passive houses

According to the definition, passive houses inEurope meet a target energy demand for heatingof less than 15 kWh per square meter and peryear. This low level for the heating demand isbased on heating by a small post-heater in thehygienic ventilation system at 52 C maximum,while the ventilation system can be dimensionedpurely for ventilation purposes. In theory thusthe installed heating power is less thanapproximately 10 watts/m2.But what happens in practice? The practicalrealization can be different from the definitionand user experiences with indoor climatesystems for passive houses may require furtheradaptations. Belgian example projects and theindoor climate systems in winter and in summerwere studied. The study includes inspection oftechnical details and interviews with occupantsof some passive houses in Belgium.The results illustrate the concerns ofoccupants considering winter and summercomfort in especially bedrooms, low airhumidity creating respiratory problems andcomplex control of installations includingtemperature control. The research shows thatoccupants tend to prefer new adapted types ofpost-heating. Also, a good realization of(passive) cooling techniques is a very importantissue in passive houses.The paper gives recommendations on howto improve the user friendliness of indoorclimate systems for passive houses.