Micro-environmental control for efficient local cooling: Results from manikin and human participant tests
Worked with Meng Kong, Jianshun Zhang, Thong Q. Dang, Alan Hedge, Brian Carter, Chetna Chianese, H. Ezzat Khalifa,
The project is aimed at developing a Micro-Environmental Control System to help restore the occupant's thermal comfort when the building background temperature set-point is relaxed from 70-75?F to 66-79?F to save building energy. I was acting as an experiment designer in this project to collect user data and analyze the data when I was a PhD student in the Department of Design and Environmental Analysis at Cornell University.
Abstract
The micro-environment in this study refers to the air space and environment around a person that directly impacts their thermal sensation. This study aims at evaluating the performance of a newly developed micro-environmental control system (μX) designed to cool the occupants locally for thermal comfort when the temperature in the ambient unoccupied space is raised from 23.9 °C to 26.1 °C in summer to reduce the HVAC cooling load. The μX was tested first with a 20-segment thermal manikin wearing summer clothing in a full-scale stainless-steel chamber and then with human participants in a climate chamber. Results show that the heat loss by the manikin increased with the distance between the μX air supply diffuser and the manikin and decreased with the clothing insulation. Changing the air delivery angle from 0° to 10° from the horizontal direction resulted in additional heat loss from the manikin. The heat loss from the manikin was found to be positively correlated with the supply air flow rate, but negatively correlated with the supply air temperature. However, the overall cooling efficiency dramatically increased with the supply air temperature. Overall, both the manikin test and the human participant test showed that the μX was able to cool the occupant in a room of expanded temperature set-point, and the Clothing Independent Thermal Comfort Model gave a consistent prediction with the human participant test. However, slight thermal discomfort was reported when the μX was used due to the effect of clothing, season, metabolic rate and local draught.
The paper has been published at Building and Environment, Volume 160, August 2019, 106198
Kong, M., Zhang, J., Dang, T.Q., Hedge, A., Teng, T., Carter, B., Chianese, C. and Khalifa, H.E., 2019. Micro-environmental control for efficient local cooling: Results from manikin and human participant tests. Building and Environment, 160, p.106198.
DOI: 10.1016/j.buildenv.2019.106198
