On the effectiveness of passive controls for summer thermal comfort in highly insulated dwellings

ABSTRACT

Among environmental controls, solar shading and ventilative cooling are widely considered as key passive strategies for limiting the overheating risks in buildings. While their application is encouraged through Energy Performance of Buildings Directive regulations, several studies have shown that summer thermal comfort in heating-dominate temperate climates still requires deeper investigation, particularly in low-energy residential buildings. Based on qualitative and quantitative data collected through surveys and monitoring in 147 highly insulated houses in Wallonia (Belgium), this paper gives an overview of the implemented passive strategies and discusses their effectiveness. Statistical tests are conducted to evaluate their impact on both perceived and measured indoor conditions. In general, the results highlight a limited impact of the implemented strategies, questioning their proper operation. Operational modes for environmental controls thus appear crucial, and should better respond to occupants’ needs, preferences and control opportunities. At a more general level, the study calls for a better understanding of the barriers inhibiting successful integration and operation of environmental controls, in order to effectively reduce overheating risks in residential buildings and limit future diffusion of active cooling systems with their induced environmental impacts.

KEYWORDS:

• Solar shading
• ventilative cooling
• passive strategies
• summer thermal comfort
• overheating
• highly insulated buildings

Acknowledgements

The post-occupancy measurement campaign was carried out in partnership with the Belgian Building Research Institute (BBRI) within the MEASURE project (Real performance and occupant satisfaction measures in high energy performance residential buildings (2013–2018)). Data were re-analysed as part of the SOFTSummer project (Smart Operation For Thermal Summer comfort in residential buildings (2022–2024). Both projects received the financial support from the Wallonia region. The authors also want to thank Marshal Maskarenj for his careful proofreading of the paper.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Funding

This work was supported by Service Public de Wallonie (grant numbers 1350531 and 2110179).