## 1 Introduction  
Energy consumption is one of the most important factors to be considered in the design of new buildings, which is also an index that the existing buildings need to improve [1]. Recent research has shown that the energy consumption of commercial and residential buildings is responsible for approximately 40% of the total energy consumption [2]. The amount of energy used in heating, ventilation, and air-conditioning (HVAC) systems accounts for almost half of the energy consumption in buildings [3]. The energy consumed is primarily used to create a healthy and comfortable indoor environment [4]. Reducing energy consumption while meeting indoor environmental requirements is important in mitigating carbon emissions. Considering that people spend more than 80% of their time indoors [5], an environment with poor indoor air quality can cause diseases such as sick building syndrome [6], which can seriously affect the health of occupants [7]. Since the COVID-19 pandemic, with aerosol transmission as a main route of transmission, indoor air quality has become a focus of attention. In an indoor environment, ventilation can effectively mitigate airborne transmission risk in confined spaces [8]. Thus, optimizing the ventilation control method [9] and using advanced air distribution [10, 11] were considered to improve the ventilation efficiency in this study. As air distribution advances [12], stratum ventilation (SV) is an excellent potential solution for both substantial energy savings and air quality [13]. The conditioned clean air is supplied directly to the breathing zone through air inlets installed at the mid-level on the side walls [14], which shortens the supply air path. The thermal neutral temperature of SV is approximately 27 \({}^{\circ}\)C, 2.5 \({}^{\circ}\)C higher than that of mixing ventilation, and 2.0 \({}^{\circ}\)C higher than that of displacement ventilation [15]. The energy savings of SV were found to be at least 44% and 25% per year compared to mixing ventilation and displacement ventilation, respectively [16]. Experimental results indicate that SV can provide satisfactory overall and local thermal comfort at a room temperature of 27 \({}^{\circ}\)C [15; 17], with small vertical air temperature differences between the head and foot [18]. SV can also provide good air quality [18]. [PERSON] et al. [19] investigated gaseous contaminant diffusion under SV and found that the concentration along the supply air jet was lower than in other parts of the room. Recent studies have been conducted to improve the performance and increase the application of SV. [PERSON] et al. [20] proposed a subzone control method for SV to improve thermal comfort. Compared with the conventional method, the advanced method reduced the deviation between the PMV (predicted mean vote of thermal sensation) in the subzone and the preferred one by 17.6-41.5%. A robust thermal deviation evaluation method was proposed for the design optimization of air distribution [21]. The robustly optimized constant air volume system of SV increased thermal comfort by 8.5% compared with one of the variable air volume systems. [PERSON] et al. [17] conducted a subjective study in an environment room with SV to evaluate the effects of temperature and supply air velocity on thermal comfort. Experimental and computational fluid dynamics (CFD) simulation studies have validated the feasibility of SV in multirow rooms [22]. [PERSON] et al. [23] considered a walking occupant in typical offices and found the application potential with frequently walking occupants compared to traditional ventilation methods. Studies have reported that SV performance is affected by the design parameters. [PERSON] et al. [24] conducted experiments and found that exhaust location and supply airflow rate can affect air diffusion. [PERSON] et al. [25] studied four exhaust types for SV, and the results indicated that rear-middle-level-exhausted SV can satisfy human comfort needs with the least energy consumption.