Investigation of bio-signal changes of occupants resting in buildings using local cooling and heating seats

• Published in: Energy and buildings 2021-08, Vol.245, p.111092, Article 111092
• Main Authors: Lee, Minjung, Shin, Yunchan, Lee, Hoseong, Cho, Honghyun
• Format: Article
• Language: English
• Subjects: Cold water; Comfort sensation vote (CSV); Concentration level vote (CLV); Cooling; EEG; Electric heating; Electroencephalogram (EEG); Electroencephalography; Environmental changes; Heating; Hot water heating; Indexing; Photo-plethysmography (PPG); Questionnaires; Seats; Stress index; Surface temperature; Thermal sensation vote (TSV)
• ISSN: 0378-7788; 1872-6178
• DOI: 10.1016/j.enbuild.2021.111092

•Biosignals and surface temperature of subjects were measured under resting conditions.•Subjective questionnaires and concentration was investigated experimentally.•Cold water seat ensures a stable rest environment for the subjects.•Electric heating seat provided a comfortable and high concentration environment in heating mode. The electroencephalogram (EEG), photoplethysmography (PPG), subjective questionnaires, surface temperature, and concentration of subjects for various resting conditions in the building under cooling and heating conditions were investigated to improve their quality of rest and examine the effect of environmental changes on various biosignals comprehensively. As a result, the use of a cold water seat during a rest under cooling condition activated θ wave and α wave in the subjects and decreased low frequency/high frequency (LF/HF) ratio and stress. In addition, the hot water seat used during a rest under heating conditions provided subjects with a stable rest environment because it activated the PPG and θ wave of the subjects and decreased the LF/HF ratio. However, the stress index of the subjects was slightly higher when electric heating and hot water seats were used. The subjective questionnaire showed that the use of an electric heating seat provided subjects with a comfortable environment and high concentration compared to those of other seat types.