Effect of heat source conditions on vertical temperature distribution characteristics for attachment ventilated spaces

School of Building Services Science and Engineering, Xi’an University of Architecture and Technology, 710055 Xi’an, China

^* Corresponding author: liag@xauat.edu.cn

Abstract

The vertical temperature stratification in attachment ventilation systems is closely related to room cooling/heating loads, energy efficiency, and indoor thermal comfort. The vertical temperature distribution in space is intricately interconnected with the supply air parameters and heat source conditions. In this study, for attachment ventilation in cooling mode, the temperature distribution in the ventilated room with a local heat source (point heat source, plane heat source, or volumetric heat source) was studied experimentally. The variations in vertical temperature distribution and heat distribution coefficients within the space for different heat source sizes, heat source power, and supply air velocities were investigated. The results show that the air temperature at the same height is essentially uniform except for the region where the dimensionless height above the heat source h^*≤0.56. Temperature stratification phenomena exist in the vertical direction. In the attachment ventilated space with a local heat source, the thermal stratification height is significantly influenced by the supply air velocity and the form of the heat source, while the heat source power has little effect. Compared to the plane heat source, the volumetric heat source with the same projected area exhibits smaller temperature gradients and higher stratification height.