Low-Energy Wearable Cooling Strategy for Thermal Comfort at a Warm Environment

The objective of this study is to assess the effectiveness of wearable cooling in improving thermal comfort for a warm environment that would become prevalent due to more frequent extreme weather events, especially when air conditioning is not accessible for many developing countries. The experiment was conducted in an environment room with air temperature maintained at 31 °C and relative humidity at 55%. The study tested 30 participants using a wearable cooling device at the upper back location, while another 30 had no local cooling as the control group. Participants’ thermal comfort, thermal sensation and other metrics were assessed three times for a test session. The clothing insulation was 0.36 clo to simulate summer attire. The results showed significantly lower average local and whole-body thermal sensation for the participants with the wearable cooling device than the control group by considering all the votes during the entire session. Compared to the baseline, in particular, the local cooling group indicated a significant reduction in local thermal sensation for all three times of self-evaluation. Nevertheless, the reduction in overall thermal sensation occurred right after the local cooling was applied. Such a significant reduction was not observed after a while and then emerged again during the test, indicating an interactive phenomenon involving thermal adaptation and comfort restoration which will be investigated in the future.