## 1 Introduction
[11] conducted a study on office buildings in Tokyo, Japan. They investigated the impact of four design variables of the outer envelope structure on the cold and heat load of buildings. These variables were the solar heat gain coefficient of the outer window, the heat transfer coefficient of the outer window, the heat transfer coefficient of the opaque envelope, and the solar reflectivity of the opaque envelope. [PERSON] [12] provides the comprehensive mechanism of using the digital twin and the impact assessment of interventions at the local as well as global scales. The measures of passive energy storage based on phase-change energy storage materials are studied, and the energy efficiency can be increased by 40% by adding relevant interventions. Natural ventilation refers to the use of natural airflow to achieve indoor air circulation and renewal in a ventilation mode. The principle of natural ventilation mainly includes three aspects: the buoyancy principle, the wind pressure difference principle, and the wind force principle. Natural ventilation is a fundamental and sustainable solution to reduce the energy needs of buildings for ventilation and cooling [13]. Research in this field has demonstrated that natural ventilation has the potential to save energy. [PERSON] et al. [14] conducted a study on the energy-saving potential of natural ventilation in various Chinese cities. The results indicated that natural ventilation could save between 8% and 78% of cooling energy. Similarly, in warm weather, the use of natural ventilation can avoid the need for 54.4% of the power required for cooling [15]. [PERSON] et al. [16] investigated the impact of mixed ventilation on zero-energy residential buildings. The results indicate that the combination of night ventilation and mechanical ventilation can reduce the demand for cooling capacity by 14.4%, while natural cooling can reduce power consumption by 7.7%. [PERSON] et al. [17] analyzed the importance of natural cooling and mixed ventilation systems for near-zero-energy buildings. Studies on all-glass buildings have shown that energy consumption can be reduced by up to 26% through night ventilation and mixed ventilation cooling. In summary, numerous scholars have conducted extensive research on the influence of various parameters, including window-to-wall ratio, building size coefficient, and thermal resistance of outer protective structures, on building energy conservation. It is worth noting that China's construction industry accounts for over 20% of the country's total energy consumption, with winter heating alone accounting for 20% of the total building energy consumption [13]. The energy-saving potential of HVAC systems in substation sites located in cold areas requires further investigation. Substations are typically situated in remote areas, far from residential areas. As a result, there is no urban heating network available, and traditional urban central heating is not feasible. Additionally, heating pipes cannot pass through the transformer room, distribution unit room, and other electrical equipment rooms in most substations. Therefore, given the extreme outdoor conditions of \(-30\)\({}^{\circ}\)C in winter in high-cold areas, improving heating efficiency and reducing heating energy loss in substations are crucial to enhancing the energy consumption structure and efficiency of substation buildings. This is necessary to ensure the normal operation of zero-carbon building design concepts and typical room equipment in substations under low-temperature conditions. Based on theoretical calculations and software simulations, this paper provides recommendations for selecting ventilation and heating equipment for typical rooms in high-cold area substations.