Comparative study on the thermal characteristics under different air distribution strategies oriented to non-uniform environment: An indoor experiment

With the epidemic becoming normal and realizing carbon neutrality goals, many scholars are focusing on finding reasonable air distribution strategies to provide a healthy indoor environment effectively. Hence, this study conducted a comparative experiment on the thermal characteristics under different air distribution strategies, namely interactive cascade ventilation (ICV), displacement ventilation (DV), stratum ventilation (SV), and underfloor air distribution (UFAD). Visualized and objective experiments were introduced to investigate the airflow characteristic, energy consumption and thermal comfort. The research results demonstrate that while maintaining the same supply air volume, ICV has the fastest response rate with the shortest spread-over time. Due to the dependence on the thermal buoyancy of DV, its delivery time is up to 134s. With the visualization experiment going on for 60 s, the effective outdoor air of ICV is 25.6% and 26.6% higher than SV and UFAD, respectively. In terms of energy consumption, compared to SV and UFAD, ICV enhances temperature drop per unit cooling capacity (TDCC) by 28.5% and 36.8%, showing the most significant local control ability, which is of great significance for epidemic prevention and control as well. Although the local coefficient of cooling capacity utilization (LCU) under ICV is similar to that under DV, the ICV can reduce the sizeable vertical temperature gradients under DV and improve the temperature uniformity of the occupied zone by 77.5%. The conclusions obtained from this study can efficiently provide new insights for building a healthy indoor environment with the epidemic normalizing.