Effectiveness of passive climate change adaptation measures in Switzerland: A climate-based analysis on natural ventilation and overheating risks reduction in dwellings

Building energy codes have been implemented in Switzerland as well as across the world to reduce building energy consumption, however, due to the progressive effect of climate change phenomena and the precipitate change in occupancy patterns due to the global pandemic, their effectiveness and limitations must be constantly re-examined. This paper explores the effectiveness of natural ventilation as a passive cooling strategy, as well as the overheating patterns in dwellings across the Swiss territory. The work is based on a climate-based simulation model at a territorial scale, from which the building performance is further analysed considering the heating energy consumption and overheating risk hours above 26.5°C. The effectiveness of natural ventilation through the operable window operable area in reducing overheating risk was also estimated. The results show the effectiveness across the whole territory of the current regulation (SIA 380/1:2016), which is focused on the performance of the building envelope to reduce heat losses. An unattended alarming overheating pattern was spotted in locations with altitudes below 1500 meters as a direct consequence of the climate change phenomena, hence a series of recommendations are proposed to update and improve the current legal requirements.

Shading and daylighting strategies in classrooms: a comparative study in the four climate zones in Greece using Daylight Factor values

The present work focuses to the efficient use of daylight in school buildings, which has been proved that is able to create a pleasant atmosphere, increase student productivity and comfort and also contribute to energy savings if combined with a daylight-responsive control system. The architectural-bioclimatic design contributes to the creation of technical solutions that provide daylight in existing classrooms, taking into account the climatic conditions and the needs of users. The purpose is to investigate the most prevalent shading and light redirection systems in a typical Greek classroom, in every climatic zone of Greece and come up with the most efficient ones. Research takes into consideration the distribution of daylight on working level and the total heating energy consumption throughout the school year, ensuring conditions of visual comfort. After evaluating and comparing the data, the outcome of this research demonstrates the most efficient shading system for each climatic zone, in order to achieve visual comfort and energy savings.

Comfort and efficiency-based improvements to the control of residential Venetian blinds

This study focuses on the control of movable Venetian blinds. Multiple improvements to an existing on/off open-loop control strategy in a case-study apartment have been simulated in TRNSYS 18, thanks to the detailed optical and thermal modelling allowed by the Bidirectional Scattering Distribution Function (BSDF) used as input to the Type56_CFS. The control strategy improvements include the combination of rule-based, closed-loop and discrete state control, in addition to four control strategy activation methods (three use a schedule, and one measures the external temperature). Simulated control inputs include internal temperature, external temperature and vertical irradiance. The results show reductions in overheating, achieved without completely blocking natural illumination or compromising heating demand. While on/off control in winter often leads to increased heating energy consumption, the space sees regular overheating when on/off control is inactive over winter. Conversely, discrete state control is able to more precisely control solar gains in winter to maintain an adequate temperature without utilising the heating system, all the while allowing some level of natural illumination. Ultimately, it is concluded that the choice of the control strategy depends on which objective (minimisation of heating energy consumption, maximisation of daylight harvesting, reduction of overheating risk, etc.) is prioritised.