Thermal responses and comfortable evaluations under variable dynamic environment: A case study of MAV

¹ Key Laboratory of Green Built Environment and Energy Efficient Technology, Beijing University of Technology, Beijing, China
² Department of Architecture, Tokyo Polytechnic University, Tokyo, Japan

Abstract

With the improvement of living standards, the requirements of occupants tend to be diverse. A representative adaptive strategy of variable dynamic ventilation, Multi-vent module-based adaptive ventilation (MAV), is regarded as the research object. Previous studies have showed its advantages in contaminant diffusion control and thermal comfort improvement. One of the characteristics of dynamic variable ventilation is its temporal and spatial distribution. Little is known about its dynamic thermal comfort characteristics. To explore the change of indoor parameters under dynamic ventilation conditions and its possible influence on occupants, a MAV system which can be combined to different modes was introduced to conduct simulations and human subject experiments. In the experiment, airflow organization around the subjects was changed. In dynamic switching, physiological parameters (skin temperature) and questionnaire feedbacks (thermal sensation vote, thermal comfort vote, etc.) were collected to analyse the dynamic response of individual’s perceptions. Results show cross mode enhances human perception, reduces discomfort compared to MAV vertical mode. Skin temperature decreases by about 4.25°C from top to bottom. Temperature of the chest and back of the hand showed a significant decrease within 5 minutes of the switching operation taking place. Our next endeavor involves examining the disparities between subjective and objective evaluations using numerical transient simulation to better predict thermal sensation and comfort under variable dynamic environment. Focusing on dynamic thermal environment, these results can provide useful reference for people-oriented dynamic variable ventilation design.