Inclusive comfort: A review of techniques for monitoring thermal comfort among individuals with the inability to provide accurate subjective feedback

Indoor thermal comfort plays a crucial role in human health, productivity, and energy consumption. Traditional thermal comfort surveys rely on subjective feedback from participants. However, acquiring such feedback becomes challenging when considering specific demographics, such as individuals with cognitive or physical impairments. Addressing this gap is vital, especially as global demographic shifts point towards an increasing elderly population and heightened awareness of inclusivity for individuals with disabilities. This comprehensive review explores the monitoring techniques investigating indoor thermal comfort in individuals who cannot provide accurate subjective thermal comfort feedback, examining literature spanning the past 24 years. For the purposes of this study, individuals in this group have been categorized into three distinct categories: those who are asleep, elderly and disabled individuals with impaired thermal comfort feedback ability. The review reveals that the thermal comfort preferences of these specific populations differ from those of adults with unimpaired feedback capabilities, necessitating personalized approaches in thermal comfort studies. Moreover, marked individual variances exist within these demographics, which can potentially be attributed to factors such as overall health status, specific ailments, and age. The review expounds upon four distinct research methodologies: adaptive behaviour observation, the dual questionnaire survey method, the third-party questionnaire survey method, and the intelligent identification technique. It discusses each methodology's process, advantages and disadvantages, and suitable target groups. For instance, adaptive behaviour observation is effective for individuals with some mobility, while dual questionnaire surveys are more suited for the sleeping population. Third-party surveys, which largely depend on support persons, such as caregivers, are valuable for individuals with moderate to severe disabilities. The study concludes with recommendations for future studies, emphasizing the importance of regional comparative studies, the development of ethical frameworks for intelligent systems, and the exploration of real-time adaptive environmental systems. These efforts aim to enhance understanding and improve thermal comfort for these vulnerable populations, ensuring inclusive comfort aligned with evolving technological capabilities and ethical standards.