• Energy Research

Towards a carbon-neutral society, the building sector has a pivotal role with still a great potential for improvement. A new generation of buildings is rising but, to set a more ambitious shift in the paradigm and to fully justify the additional efforts (technological and economic) needed to fill the gap between net zero and plus energy performances, it is essential to consider not only the direct effects, but also all the indirect impacts. However, research conducted in the last decade solely focuses on the direct effects, mainly energy savings, while the indirect impacts neither have a clear identity nor terminology and a defined list of the impacts and methodologies for their quantification is still missing. With these premises, a systematic literature review on the current state of the art was performed in this work, with the aim of (i) investigating the heterogeneous terminology used for such indirect effects, (ii) identifying a final potential list of impacts both at the household and at the community level and (iii) their macro-categorizations, and (iv) exploring the current implemented methodologies and indicators for an economic quantification. As a final result of the analysis, the authors propose a unique terminology for addressing the indirect effects of high-performance buildings. This paper sets the needed basis and common ground for future research in this field, meant to economically quantify the indirect effects in the building sector.

In warm climates, resilient and low-energy methods for cooling building occupants are needed to ensure energy-efficient and adaptive thermal comfort. Air movement, particularly through ceiling fans, is an effective way to provide comfort in warm conditions, potentially minimizing or even avoiding the need for more energy-intensive air conditioning systems. This study aims to validate an algorithm for automatically adapting ceiling fan speed in residential settings based on room thermal conditions and focuses on subjective thermal satisfaction and perceived air quality (PAQ). An environmental chamber study was conducted with 30 participants across three different indoor air temperature conditions (27 °C, 29 °C, and 31 °C) over 2-hour sessions, testing four fan operational modes: Automatic (downward flow), Manual Direct (downward flow), Manual Reverse (upward flow), and Off. Subjective thermal satisfaction and PAQ were measured using standardized questionnaires on a 7-point Likert scale. Results showed that automatic operation maintained comparable thermal satisfaction levels to manual control, with no statistically significant differences (p > 0.3) across all temperature conditions, indicating that the automatic algorithm successfully provided comfortable environmental conditions comparable to user-controlled settings. Direct flow mode (downward) significantly outperformed reverse flow mode in thermal satisfaction, especially at higher temperatures (29 °C and 31 °C, p 0.2), while manual and off modes showed decreased satisfaction, particularly from 27 °C to 31 °C (p < 0.05). These findings demonstrate that automatic ceiling fans can achieve equivalent comfort satisfaction to manual operation while enabling a more energy-efficient alternative to traditional air conditioning. The validated automatic control system provides a practical pathway toward resilient and personalized cooling strategies in residential buildings, contributing to both climate change mitigation and the achievement of plus-energy building goals.

Despite the multifaceted nature of notion of thermal comfort, designers have embraced a very strict definition of it, which consists of very tight and static environments, were transition and stimuli are not admitted, and with very narrow ranges of microclimatic parameters required equally for all the subjects. This neglects all the potential implications related to different users. However, when it comes to thermal comfort, the long-term history of subjects and their climatic background play a pivotal role towards their own thermal sensations and preferences. In this work, to address these diversities, the authors analysed the existing database of the Smart Controls and Thermal Comfort (SCATS) project, which was built from monitoring and survey campaigns conducted in the late 90s in five different European countries. Data were studied by means of statistical techniques to grasp and define the potential combined influence of climatic location, seasonal variations, subjective variables and ventilation modes on the occupants’ thermal feeling and preference. Different scenarios recommended by standard EN 16798 were tested to address the differences in the thermal feelings of users living in different European countries. Finally, country-based operative temperatures that optimize users’ thermal feeling and preference were determined. Results highlight that users in different countries differently evaluate indoor thermal parameters both in terms of thermal feeling and thermal preferences. This results in differences among countries for acceptability levels associated with standardised indoor conditions. Furthermore, the results highlight the importance of air movement to improve acceptability at higher indoor temperatures for all the countries.

AbstractThis work presents an assessment of schools’ indoor environmental quality, based on investigations carried out in three Italian classrooms in Treviso, in the North-East of Italy. A first monitoring campaign was performed during the mid season (May-June), a second one during the heating period (January-February). At a first stage, the study was focused on two different approaches, an objective and a subjective one, in order to compare the objective responses with the occupants’ subjective sensations. The first method consisted of physical observations and field measurements of thermal environmental parameters, used to calculate Fanger's comfort indices and to apply a comfort adaptive model. The subjective approach was managed by giving students and teachers a survey about their personal judgment concerning the level of comfort perceived. Finally, a simulation model has been built-up and calibrated using the indoor values of air temperature and air humidity trends collected by data loggers. A generic optimization program has been used to calibrate the thermal model. The responses from measurements, surveys and simulations were integrated, analyzed and compared, obtaining a good agreement between the three approaches in assessing the classroom thermal comfort category.