Perceived and measured indoor climate conditions in high-performance residential buildings

• The indoor climate in a high-performance multifamily building was evaluated based on a user survey and measurements.
• The results support earlier findings that indicate an improved indoor air quality in mechanically ventilated residential buildings.
• A clear need for temperature zoning and a desire of lower bedroom temperatures was observed.
• The heating and ventilation system as well as the user knowledge and awareness need to be improved to achieve thermal comfort in bedrooms.

The implementation of mechanical ventilation systems with heat recovery (MVHR) in new high-performance residential buildings constitutes a fundamental change from traditional heating and ventilation strategies. A MVHR with one ventilation zone, which is commonly used in new residential buildings, will supply approximately the same temperature to all rooms and consequently contribute to balancing the room temperatures within the dwelling.This change affects air change rates, the air distribution between rooms and temperatures, and consequently calls for an evaluation of the impact on the perceived and actual indoor climate and of to what degree the desired indoor climate conditions are provided. Therefore, a post-occupancy evaluation (POE), consisting of a user survey and long-term measurements, is performed for a high-performance residential project in Norway.The results support earlier findings that indicated an improved indoor climate in high-performance residential buildings with MVHR compared with other building standards.However, the findings clearly demonstrate a need for temperature zoning in residential buildings. The preferred lower bedroom temperatures appear to be difficult to achieve in common high-performance building concepts with MVHR. An important factor that influences bedroom temperatures was found to be the control strategy for the supply air temperature, where a potential for improvement was observed.