Subzone control method of stratum ventilation for thermal comfort improvement

Zhang, S; Cheng, Y; Oladokun, MO; Lin, Z

Abstract

The conventional control method of a collective ventilation (e.g., stratum ventilation) controls the averaged thermal environment in the occupied zone to satisfy the averaged thermal preference of a group of occupants. However, the averaged thermal environment in the occupied zone is not the same as the microclimates of the occupants, because the thermal environment in the occupied zone is not absolutely uniform. Moreover, the averaged thermal preference of the occupants could deviate from the individual thermal preferences, because the occupants could have different individual thermal preferences. This study proposes a subzone control method for stratum ventilation to improve thermal comfort. The proposed method divides the occupied zone into subzones, and controls the microclimates of the subzones to satisfy the thermal preferences of the respective subzones. Experiments in a stratum-ventilated classroom are conducted to model and validate the Predicted Mean Votes (PMVs) of the subzones, with a mean absolute error between 0.05 scale and 0.14 scale. Using the PMV models, the supply air parameters are optimized to minimize the deviation between the PMVs of the subzones and the respective thermal preferences. Case studies show that the proposed method can fulfill the thermal constraints of all subzones for thermal comfort, while the conventional method fails. The proposed method further improves thermal comfort by reducing the deviation of the achieved PMVs of subzones from the preferred ones by 17.6%–41.5% as compared with the conventional method. The proposed method is also promising for other collective ventilations (e.g., mixing ventilation and displacement ventilation).

Citation

Zhang, S., Cheng, Y., Oladokun, M., & Lin, Z. (2019). Subzone control method of stratum ventilation for thermal comfort improvement. Building and Environment, 149, 39-47. https://doi.org/10.1016/j.buildenv.2018.11.041

• Journal Article Type: Article
• Acceptance Date: Nov 13, 2018
• Online Publication Date: Dec 6, 2018
• Publication Date: Feb 1, 2019
• Deposit Date: Jan 30, 2020
• Publicly Available Date: Jan 30, 2020
• Journal: Building and Environment
• Print ISSN: 0360-1323
• Publisher: Elsevier
• Volume: 149
• Pages: 39-47
• DOI: https://doi.org/10.1016/j.buildenv.2018.11.041
• Publisher URL: https://doi.org/10.1016/j.buildenv.2018.11.041
• Related Public URLs: https://www.sciencedirect.com/journal/building-and-environment
• Additional Information: Funders : General Research Grant from the Research Grants Council of the Hong Kong Special Administrative Region, China;Fundamental Research Funds for the Central Universities, China; Grant Number: CityU 11210617; Grant Number: 2018CDXYCH0015