In the initial stage of my country's advocacy of building energy efficiency, the attention of the society was mainly focused on the insulation and heat insulation of the building envelope-doors and windows, walls, roofs, etc. However, with the continuous development of building energy conservation in my country, the energy-saving technology of building envelopes is gradually improving. Fresh air accounts for an increasing proportion of the energy consumption of the entire building. The energy-saving space of the fresh air system is gradually emerging, and the More and more people are paying attention. According to the survey, the energy consumption of public institutions is mainly composed of building energy consumption, which accounts for 70% of the total energy consumption of public institutions. In the energy consumption of buildings, the use of air conditioning is the most power-consuming equipment in the building energy consumption. The survey results of the Beijing Institute of Refrigeration show that of all public buildings in Beijing, shopping malls account for 5 of the building area. Among them, the power consumption of buildings with central air-conditioning accounts for 35% of the city’s building power consumption. Compared with the energy saving of household air-conditioning, which has been launched for many years Compared with the upgrade, the energy saving of central air-conditioning has been slow for many years. Relevant organizations recommend based on the survey results to set the levels of elimination-level central air-conditioning and energy-saving central air-conditioning. Central air-conditioning with an energy efficiency ratio below 4.0 is an elimination-level product, and an energy-efficiency ratio of 5.1 is an energy-saving product.