On the other hand, a study in subtropical regions showed that the preferences for air movement largely differed between the responders, and another report from a subtropical region showed that fewer people preferred air movement when the room temperature in an air-conditioned environment increased. Some studies have investigated the preferences for airflow movement through subjective votes, showing that air movement was preferred when people felt warm or slightly warm. Satisfaction with airflow direction will improve quality of life and promote better productivity in offices and schools.ĭiscomfort under different indoor airflow velocities has long been studied, and satisfaction varies depending on temperature, climate, and individuals. When evaluating thermal comfort, air movements are regarded as unwanted because high wind velocities decrease indoor comfort. The results of this study suggest that physiological measurements can be used for the evaluation of unconscious indoor comfort, which cannot be detected by subjective evaluations alone.Īirflow movement and direction can influence the comfort level in a heating environment.

Our results suggest that indirect heating airflow causes lower mental stress and fatigue than those induced by direct flow, which is equivalent to more comfort. The amplitudes of gamma and beta waves showed significant correlations with anxiousness levels (gamma, T3: r = 0.41 beta, T3: r = 0.35). Similarly, the variability of respiration was lower under the indirect condition ( p < 0.010). The gamma and beta bands of electroencephalograms taken at the left-temporal (T3) and left-parietal (P7) sites showed significantly lower amplitudes under the indirect condition (gamma, T3: p = 0.034, P7: p = 0.030 beta, T3: p = 0.051, P7: p = 0.028). The mean speed of the air directed to the participants’ faces was 0.123 m/s and 0.225 m/s in the indirect and direct conditions, respectively. They were exposed to indirect and direct airflow toward their faces and performed four tasks under each condition: resting, counting to 10 s following time alerts, counting to 10 s in the mind, and mental calculation. Twenty participants entered a test room at 30 ☌ after staying in an acclimation room at 18 ☌ for 20 min. This study evaluated airflow and thermal comfort through physiological measurements, including skin temperature, electroencephalography, respiration, and electrocardiography, in addition to subjective evaluations. Thus, subjective evaluations should be combined with objective assessments, such as physiological measurements. Indoor airflow and thermal comfort are difficult to assess through subjective evaluations because airflow sensations can differ based on various factors, such as personal characteristics, interests, preferences, and the current state of mind.

Direct airflow technology