TY  - EJOU
AU  - Liu, Dong 
AU  - Zhang, Runze 
AU  - Hu, Anjie 
AU  - Liu, Na 
AU  - Tang, Liu 
AU  - Wu, Xiaozhou 
AU  - Wang, Jun 

TI  - Impact of Window-to-Wall Ratio on Thermal Comfort and Energy Performance of Hybrid Cooling Systems
T2  - Fluid Dynamics \& Materials Processing

PY  - 2025
VL  - 21
IS  - 10
SN  - 1555-2578

AB  - This study compares two end-cooling systems, convective–radiant combined cooling (FR+FC) and fan coil convection (FC), through continuous experimental investigations, focusing on the impact of window-to-wall ratio (WWR) on indoor thermal comfort, temperature distribution, humidity, and energy consumption. Results show that increasing WWR amplifies indoor temperature fluctuations. While the overall predicted mean vote (PMV) remains within the Level-II comfort range (−1.0 to +1.0), the FC system exhibits pronounced local PMV gradients near west-facing windows, especially at 80% WWR, where transient PMV reaches 1.26 close to the window, 0.89 higher than at the room center. In contrast, the FR+FC system significantly reduces spatial PMV variations, maintaining local PMV within acceptable limits for most of the day. Energy analysis reveals that FC energy consumption rises with WWR, increasing by 7.11% from 40% to 80% WWR, whereas FR+FC energy use decreases by 29.26% over the same range, demonstrating its superior handling of radiant loads. Furthermore, the convective–radiant system exhibits a high average hourly cooling performance coefficient. These findings indicate that FR+FC systems provide better thermal comfort and energy efficiency in high-WWR spaces, making them particularly suitable for summer operation in window-intensive buildings.
KW  - Window-to-wall ratio; solar radiation; thermal comfort; energy consumption

DO  - 10.32604/fdmp.2025.070407