Thermal comfort chamber study of Nordic elderly people with local cooling devices in warm conditions

In this study, we investigated the thermal response of Nordic elderly people before and after using local cooling devices in warm conditions. A climate chamber was used to simulate warm environments. We studied three types of local cooling devices: a table fan, an evaporative cooling device, and an air-cooled jacket. A total of 26 elderly participants were recruited for this study. During the experiments, votes of thermal and air movement perception were collected. The elderly voted for a neutral temperature of 26 °C, preferred temperature of 26.5 °C, and an acceptable temperature of 28 °C. Local thermal sensation in the torso areas of the elderly affected their overall thermal sensation more than local thermal sensation in the extremities under warm conditions. When the ambient temperature was risen to 1 °C and 4 °C higher than 26 °C, the behavior pattern of using local cooling devices for the elderly was: 1) with the small rise the use rate reached 50% with the lower speed modes mainly chosen; and 2) the higher rise caused more people to choose higher speed modes. Our findings show that the three local cooling devices can increase thermal acceptability under warm conditions. More than 80% of elderly accepted the 28 °C thermal environment, and less than 80% accepted 32 °C. The acceptance rate for air movement after using devices was decreased and less than 80% in most conditions. Moreover, all devices performed better under low-humidity conditions. •The elderly prefers a slightly warm condition.•In warm conditions, the elderly's head and trunk thermal sensations dominate.•The use rate of local cooling devices reaches 50% around 27 °C.•Local cooling devices can improve thermal comfort, but in 33 °C with higher relative humidity, acceptance rate is below 80%.•The acceptance rate of air movement declined after using local cooling devices.