This study aimed to investigate the thermal environment and thermal comfort of elderly occupants living in elder care facilities and to compare the quality of sleep, in all four seasons, of these elderly occupants. A total of 16 healthy participants with a mean age of 80 ± 5 years (range, 70–87 years) were recruited in two elderly facilities, of which, 13 participated in all four measurements. The sleep parameter was measured by a wrist actigraph which the participants were requested to wear and analyzed with commercial software using the Cole–Kripke algorithm, to assign scores for sleeping and waking patterns. Both ambient temperature (Ta) and relative humidity (Rh) levels were found to be lower in the winter and higher in the summer. The Ta in the summer and Rh in the winter were not within the scope of the Japanese Standard for Maintenance of Sanitation in Buildings, as the central HVAC and air conditioners were turned off due to the absence of facility managers. More than 50% of the elderly occupants used fans and increased airflow by opening windows during the summer nights as an adaptive thermal approach. The slope of the relationship between prevailing mean outdoor temperature and indoor Ta determined in this study was similar to the adaptive model and the regression line lies over the upper limits of the adaptive model. No significant difference was found in the sleep parameter among the four seasons; however, a sex difference was found in the sleep latency and length of waking period during the sleep. The sleep parameters such as sleep efficiency indexes were significantly better for elderly women than men. The adaptive approach is not enough to improve the sleep efficiency of sleeping elderly people even within the acceptable temperature range based on the thermal comfort, especially for elderly men.

A strategy for effectively utilizing occupants’ adaptive behaviors (OABs) to achieve thermal acceptability while maintaining low energy consumption is necessary. This study aims to clarify the relationship between OABs and thermal acceptability over various climate zones, as well as the change in OABs due to air conditioner (AC) ownership in Indonesian residences. An online questionnaire consisting of perceived OABs’ time intensity, thermal acceptability, and personal attributes from 3000 respondents across Indonesia was analyzed using logistic regression. The results suggested that NV occupants engage in more fan usage and window opening to enhance ventilative cooling, while AC occupants are more likely to adjust clothing and use portable fans to create cooler environments. Moreover, the effects of OABs on NV residences varied depending on the local climate conditions. In hot local climates, averages of 90% fan usage intensity and 92% window opening intensity, complemented with active clothing adjustment, were unable to effectively provide thermal acceptability. These findings imply that there is a range of indoor environmental conditions in which conventional OABs work well. This study highlights the need to promote behavioral adaptations, especially in AC mixed-mode buildings, and to consider behavioral adaptations in NV buildings based on local climates.

This study develops an add-on local sweating simulation system to upgrade existing dry thermal manikins to local and sweating thermal manikins. The performance of this system was studied using a dry thermal manikin resembling a human lying on a bed with a ventilated mattress. The system comprises water-repellent porous hollow tubes to discharge water onto a diffusive fabric, as well as a motorized gear pump, DC power supply, relay module, microcomputer, and water container. Using the developed system, we maintained a cyclic steady-state for sweat generation; further, as simulated sweat, the tubes discharge distilled water over a wide area on the surface of a manikin segment covered with fabric. The local evaporative heat loss determined using the manikin roughly agreed with that calculated using the latent heat and water discharge rate, with a difference within 5 W/m². The humidity in the bed microenvironment was increased via the add-on sweat generation system and decreased via mattress ventilation. A dry thermal manikin with an add-on system is suitable for evaluating local cooling induced by sweating. The system has high repeatability (6% standard deviation); however, the accuracy of the water discharge rate (30%) needs improvement.