Sex differences in thermal sensation and EEG responses during thermal transitions in non-neutral thermal environments within buildings

The personalized comfort model (PCM) offers a promising approach to improving building energy efficiency by integrating individual physiological differences. However, sex-based variability in thermal perception remains insufficiently understood. This study investigated subjective thermal sensation votes (TSVs) and electroencephalogram (EEG) responses of male (n = 16) and female (n = 16) participants during transitions between warm – cool (PMV +2 → −2) and cool – warm (PMV −2 → + 2) environments. Significant sex differences (p < 0.05) in TSVs were observed 3–15 min after transitioning from warm to cool conditions. Despite being in the same thermally neutral – cool environment, males (TSVm = −1.15) and females (TSVf = −2.15) reported approximately a one-unit difference on the TSV scale immediately after entry. EEG analysis revealed significant sex differences (p < 0.05) in the right lateral beta (RLB), right medial beta (RMB), and sensorimotor rhythm (SMR) bands – frequency ranges associated with subjective thermal sensation – with distinct sex-specific activation observed in the occipital region. The correlation between TSV and EEG further confirmed that EEG activity reflects subjective thermal perception. These findings demonstrate that EEG can serve as a physiological indicator of thermal comfort and underscore the importance of sex-specific approaches in developing personalized thermal comfort models. Abbreviations: PCM: personalized thermal comfort model; EEG: electroencephalogram; PMV: predicted mean vote; TSV: thermal sensation vote; TCV: thermal comfort vote; RLB: Relative Low Beta; RMB: Relative Middle Beta; SMR: Sensory MotRhythm; DOE: Design of Experiments; HVAC: Heating, Ventilation, and Air Conditioning; ECG: Electrocardiogram; ASHRAE: American Society of Heating, Refrigerating and Air-Conditioning Engineers; EOG: Electrooculogram