## 3 Geographical Information  
Guangzhou City is situated in the southern region of mainland China, in the central and southern parts of Guangdong Province, at the northern edge of the Pearl River Delta. It is the confluence point for the Beijing (North River), Xijiang (West River), and Dongjiang (East River) as they flow into the South China Sea. Geographically, the city is positioned between approximately 112\({}^{\circ}\)57\({}^{\prime}\) to 114\({}^{\circ}\)3\({}^{\prime}\) E longitude and 22\({}^{\circ}\)26\({}^{\prime}\) to 23\({}^{\circ}\)56\({}^{\prime}\) N latitude (Figure 4). This paper focuses on the hottest region with hot summers and warm winters among China's five climate zones, where cooling consumption is an important component of building operation consumption [27; 28]. So, Guangzhou was selected as the illustrative example with the following main climate parameters: the annual average temperature is 22.5 \({}^{\circ}\)C, the average temperature in the hottest month is 32.9 \({}^{\circ}\)C, the annual maximum temperature is 36.1 \({}^{\circ}\)C, and the annual total solar radiation is 1072.1 kWh/year. Figure 5 gives the key climatic parameter variations throughout a typical year. China divides building climate zones into five main climate zones and 20 climate subzones. The main division index of building climate zones is the average monthly temperature in January and July. The names of thermal zones are cold region, hot summer and cold winter region, hot summer and warm winter region, and mild region. The case study building is located in Guangzhou City and belongs to the hot summer and warm winter region, that is, the average temperature in January is greater than 10 \({}^{\circ}\)C, and the average temperature in July is 25-29 \({}^{\circ}\)C. Guangzhou falls within a subtropical climate zone, characterized by distinct seasons and abundant precipitation. Summer, the rainy season, is hot and humid, influenced by tropical monsoons. Winter is warm, dry, relatively mild, and experiences minimal rainfall, shaped by the influence of northern monsoon winds. Spring and autumn boat moderate temperatures and lower humidity levels. Figure 3: Research flow chart. Figure 4: Location map of the case study city, Guangzhou, in southern China (drawn by authors). Figure 5: Cont. Guangzhou experiences its highest annual temperatures in August, reaching 37 \({}^{\circ}\)C. During the summer, temperature fluctuations are relatively minor. The lowest temperatures  
Figure 5: Key climatic parameters in Guangzhou (hot summer and warm winter climatic zone). (**a**) Average monthly temperature and solar radiation (Monthly average temperature in blue, monthly ambient radiation in orange). (**b**) Wind rose diagram (The color difference represents the wind speed in each wind direction zone). (**c**) Map of China’s 5 climate zones (The color difference represents different climate zones in China) [29]. (**d**) Information on the wind environment at the site during a typical summer month (Blue for wind speed, orange for wind direction). occur in January and February, dropping to 6 \({}^{\circ}\)C, and during the winter, temperature variations are more significant. The monthly normal direct radiation remains around 250 MJ/m\({}^{2}\) with relatively minor annual fluctuations. The monthly total horizontal radiation exhibits a trend of transitioning from low to high and then decreasing from January to December, reaching its peak in August at approximately 530 MJ/m\({}^{2}\), and reaching its lowest point in February at approximately 260 MJ/m\({}^{2}\). The wind rose diagram indicates the predominant wind directions are from the northeast and southwest in Guangzhou. Specifically, the average wind speed for the northeast wind can reach a maximum of 6.40 m per second, while the southwest wind reaches a maximum average speed of 5.80 m per second. It is evident that the average wind speed for the northeast wind is significantly higher than that for the southwest wind.