Ventilative Cooling of Residential Buildings - Strategies, Measurement Results and Lessons Learned from Three Active Houses in Austria, Germany and Denmark

The thermal comfort of the “Home for Life” dwelling in Denmark, the “LichtAktiv Haus” in Germany and “Sunlighthouse” in Austria is investigated with a particular focus on the control strategies and the role of solar shading and natural ventilation (ventilative cooling). These houses are three of six buildings in the Model Home 2020 project (Feifer, 2013). They have generous daylight conditions, and are designed to be energy efficient and CO2 neutral with a good indoor environment. The living rooms in all three houses have high daylight levels and have been selected for detailed analysis for this reason. Also analysed in detail are the master bedrooms, to investigate the sleeping environment and the potential impact on sleep quality. The thermal environment was evaluated according to the Active House specification (based on the adaptive method of EN 15251), and it was found that for 80-90% of the hours of the investigated year, the temperature in the main rooms of all houses was within Category 1. There were more hours with temperatures below Category 1, than above. The hours with temperatures below Category 1 often occurred by occupant preferences. If temperatures below Category 1 are disregarded, all main rooms achieve Category 1. In the master bedrooms, very few episodes with temperatures above Category 1 were seen, indicating a good sleeping environment. It was found that ventilative cooling through window opening plays a particularly important role in maintaining thermal comfort in all three houses and that window opening was frequently used.