Electroencephalography associated with thermal discomfort induced by temperature upward ramping

This study investigates the brainwaves associated with thermal discomfort induced by temperature upward ramping. This experiment was conducted on 35 university students. Participants stayed for 40 minutes in a climate chamber where the temperature gradually increased, and at the same time, EEG measurements and thermal comfort answers were performed. As a result of the temperature increasing, the participants felt uncomfortable and the relative power value of all frequency bands gradually increased. As a result of correlation analysis of individual thermal comfort change and relative power change, the alpha power at Cz, C3, the beta power at Fz, Cz, and C4 and the gamma power at C4 increased.publishedVersio

Association between physiological signal from wearable device and alertness of office workers

Through physiological signals, detecting the changes of occupants' physical and psychological aspects is possible, and wearable devices have enabled measurement in dailylife. In this study, to see whether the wearable device could be used for interpreting the state of the office workers, a field experiment was conducted.A wearable device was applied for monitoring the occupant, and productivity responses were collected inside a real office. As a result, when the productivity and alertness decreased, the room temperature was high, and the skin temperature and electrodermal activity were increased. A comparison between the group of alert and drowsy states was also made. The average and the gradient of skin temperature had a significant difference between the states. The result of skin temperature could be interpreted as suppressing the sympathetic nervous systems in the drowsy state, increasing blood flow, and increasing temperature at the terminal skin. Significant relation with the electrodermal activity can be explained through sweat secretion. The results showed the insight of understanding the occupants' alert state through wearable device measured data.publishedVersio

Adolescents’ thermal comfort and skin temperature compared to young adults

This study compared thermal comfort and skin temperature of adolescents and young adults to analyze the difference in their thermal responses. In a climate chamber with increasing air temperature from 18 ℃ to 32 ℃, skin temperature was measured at seven body parts with survey responses. As a result, the indoor environment, thermal comfort, and skin temperature have significant correlations, and there were differences between adolescents and adults in their responses. The neutral temperature of adolescents was slightly lower than that of adults. Generally, adolescents have a higher mean skin temperature than adults, and the hand skin temperature of the adult male group changed much sensitively corresponding to their thermal sensation than others. The difference in thermal comfort and related skin temperature implies the need for investigating adolescents as a separate group from adults for accurate thermal comfort prediction. The results are expected to be used for optimal environmental settings for adolescents.publishedVersio

The colours of comfort:From thermal sensation to person-centric thermal zones for adaptive building strategies

Thermal comfort research has been traditionally based on cross-sectional studies and spatial aggregation of individual surveys at building level. This research design is susceptible to compositional effects and may lead to error in identifying predictors to thermal comfort indices, in particular in relation to adaptive mechanisms. A relationship between comfort and different predictors can be true at an individual level but not evident at the building level. In addition, cross-sectional studies overlook temporal changes in individual thermal perception due to contextual factors. To address these limitations, this study applied a longitudinal research design over 8 to 21 months in eight buildings located in six countries around the world. The dataset comprises of 5,567 individual thermal comfort surveys from 258 participants. The analysis aggregated survey responses at participant level and clustered participants according to their thermal sensation votes (TSV). Four TSV clusters were introduced, representing four different thermal sensation traits. Further analysis reviewed the probability of cluster membership in relation to demographic characteristics and behavioural adaptation. Finally, the analysis at individual level enabled the introduction of a new metric, the thermal zone (Zt), which in this study ranges from 21.5°C to 26.6°C. The thermal sensation traits and person-centric thermal zone (Zt) are a first step into the development of new metrics incorporating individual perceived comfort into dynamic building controls for adaptive buildings

Evaluating assumptions of scales for subjective assessment of thermal environments – Do laypersons perceive them the way, we researchers believe?

International audienc

Association between physiological signal from wearable device and alertness of office workers

Through physiological signals, detecting the changes of occupants' physical and psychological aspects is possible, and wearable devices have enabled measurement in dailylife. In this study, to see whether the wearable device could be used for interpreting the state of the office workers, a field experiment was conducted.A wearable device was applied for monitoring the occupant, and productivity responses were collected inside a real office. As a result, when the productivity and alertness decreased, the room temperature was high, and the skin temperature and electrodermal activity were increased. A comparison between the group of alert and drowsy states was also made. The average and the gradient of skin temperature had a significant difference between the states. The result of skin temperature could be interpreted as suppressing the sympathetic nervous systems in the drowsy state, increasing blood flow, and increasing temperature at the terminal skin. Significant relation with the electrodermal activity can be explained through sweat secretion. The results showed the insight of understanding the occupants' alert state through wearable device measured data

Adolescents’ thermal comfort and skin temperature compared to young adults

This study compared thermal comfort and skin temperature of adolescents and young adults to analyze the difference in their thermal responses. In a climate chamber with increasing air temperature from 18 ℃ to 32 ℃, skin temperature was measured at seven body parts with survey responses. As a result, the indoor environment, thermal comfort, and skin temperature have significant correlations, and there were differences between adolescents and adults in their responses. The neutral temperature of adolescents was slightly lower than that of adults. Generally, adolescents have a higher mean skin temperature than adults, and the hand skin temperature of the adult male group changed much sensitively corresponding to their thermal sensation than others. The difference in thermal comfort and related skin temperature implies the need for investigating adolescents as a separate group from adults for accurate thermal comfort prediction. The results are expected to be used for optimal environmental settings for adolescents

Electroencephalography associated with thermal discomfort induced by temperature upward ramping

This study investigates the brainwaves associated with thermal discomfort induced by temperature upward ramping. This experiment was conducted on 35 university students. Participants stayed for 40 minutes in a climate chamber where the temperature gradually increased, and at the same time, EEG measurements and thermal comfort answers were performed. As a result of the temperature increasing, the participants felt uncomfortable and the relative power value of all frequency bands gradually increased. As a result of correlation analysis of individual thermal comfort change and relative power change, the alpha power at Cz, C3, the beta power at Fz, Cz, and C4 and the gamma power at C4 increased

User perspectives on outdoor noise in buildings with operable windows

Recent research suggests that buildings with operable windows in general, and mixed-mode (MM) buildings in particular can provide improved thermal comfort and control opportunities for users. Yet, there have been concerns about outdoor noise sources like traffic or construction noise when windows are opened. Concerns like these may hinder the installation of operable windows in buildings. This paper examines 23,000 office building occupants' perspectives on noise from both sealed and naturally ventilated/MM buildings. Results suggest thatoccupants near operable windows are more satisfied than those near sealed windows or those far from either window type. Among occupants dissatisfied with noise, complaints about indoor noise sources --like people talking-- are about 10 times more prevalent than outdoor noise complaints