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This paper presents a methodology for the application of electroencephalographic (EEG) Entropy measurements for indoor thermal comfort estimation. Wearables have been demonstrated to be capable of providing accurate physiological measurements to interpret individual thermal responses. Several studies demonstrated the correlation between the EEG Power Spectrum Density (PSD) variation and the subjects' responses exposed to different ambient temperatures. We present a complementary approach based on Approximate Entropy (ApEn) of EEG as a measure for the predictability of EEG series in describing the human thermal condition. We analysed the ApEn of EEG signals acquired from 24 subjects, exposed to three different temperatures (cold: 16°C; neutral: 25°C; warm: 33°C) in a controlled environment, by 4-channels wearable EEG sensors (256 Hz sampling frequency). Statistical analysis showed for both anterior frontal and temporoparietal sites significant differences between neutral, cold, and warm conditions, with a higher value of ApEn in the neutral one. In the anterior frontal area, there was a significative trend of ApEn with smaller values from the neutral to the warm condition, with the cold intermediate. The outcome opens the scenario up to innovative measurement systems, based on wearable EEG devices, for the application of personal comfort models to indoor environmental monitoring and control.

The recent energy crisis limits humans’ adaptation capability to climate change in indoors, making access to active air conditioning prohibitive. Since lighting systems are less energy-consuming then conditioning systems, this work focuses on visual stimuli to affect occupant’s thermal perception in the framework of the multi-domain comfort theory. Despite the Hue-Heat-Hypothesis has already been explored, validation is still missing. The following hypotheses were outlined: (i) different coloured lights lead to changes in thermal perception that are stronger under thermally comfortable conditions; (ii) visual and thermal domains synergistically interact on the overall comfort perception; (iii) skin temperature can be used as a proxy for thermal comfort. 24 volunteers were exposed to 9 scenarios combining 3 types of coloured light (white, blue, and red) with 3 temperature levels (cool, neutral, and warm conditions). Perceptual responses were collected through questionnaires and skin temperature was measured through wearable. Results support the hypothesis that bluish lights lead to cooler sensation especially in a thermally neutral environment. Skin temperature, mainly affected by ambient temperature, was not significantly related to expressed thermal comfort, apparently in contrast with previous literature results, which may highlight an interfering role of coloured lights on investigated thermal perception as cross-modal effect.

The perception of sound greatly impacts users' emotional states, expectations, affective relationships with products, and purchase decisions. Consequently, assessing the perceived quality of sounds through jury testing is crucial in product design. However, the subjective nature of jurors' responses may limit the accuracy and reliability of jury test outcomes. This research explores the utility of facial expression analysis in jury testing to enhance response reliability and mitigate subjectivity. Some quantitative indicators allow the research hypothesis to be validated, such as the correlation between jurors' emotional responses and valence values, the accuracy of jury tests, and the disparities between jurors' questionnaire responses and the emotions measured by FER (facial expression recognition). Specifically, analysis of attention levels during different statuses reveals a discernible decrease in attention levels, with 70 percent of jurors exhibiting reduced attention levels in the 'distracted' state and 62 percent in the 'heavy-eyed' state. On the other hand, regression analysis shows that the correlation between jurors' valence and their choices in the jury test increases when considering the data where the jurors are attentive. The correlation highlights the potential of facial expression analysis as a reliable tool for assessing juror engagement. The findings suggest that integrating facial expression recognition can enhance the accuracy of jury testing in product design by providing a more dependable assessment of user responses and deeper insights into participants' reactions to auditory stimuli. [ABSTRACT FROM AUTHOR]

Indoor environment significantly affects occupants' health and productivity. However, in smart buildings and cities, it can be improved thanks to the implementation of innovative ICT systems and services. Thermal comfort is one of the most complex aspects to be considered to enhance occupants' well-being, because of the relevant role played by subjective parameters (physiological, psychological and cultural) in its evaluation. This challenge can be tackled by integrating wearable devices into the monitoring framework. Thus, this paper presents an innovative methodology to measure metabolic rate (M) based on wearable devices, which can be used to apply Fanger's comfort model. This model makes use of both environmental and physiological quantities to calculate the PMV (Predicted Mean Vote) index. The former can be easily acquired through standard sensors, on the contrary, providing a good evaluation of the physiological variables of the model (i.e. metabolic rate and clothing insulation) is more difficult. In the proposed methodology, a wearable multi-parametric device has been adopted to measure data from occupants and calculate the metabolic rate. Different sets of physiological data have been investigated to derive the optimal set providing the most accurate metabolic rate. Results from laboratory tests are presented, considering activities ranging from sedentary (1 met) to more active ones (4 met). Finally, a virtual test bench has been developed to simulate a building where the methodology proposed is used to control the indoor air temperature by means of a PMV-based set-point calculation. The methodology has then been compared to traditional approaches with constant M. [ABSTRACT FROM AUTHOR]