When designing a ventilation system, the standardization and rationality of the drawings will determine the progress and effectiveness of the system's construction in the later stage. If detailed on-site inspections are not conducted in the early stage, and the building project and its requirements for the ventilation system are not fully studied, problems such as inaccurate, incomplete, and calculation errors in the drawing data will occur, which will affect the energy-saving goals and even lead to quality and safety issues. At the same time, it is also important to note that due to the large amount of calculations involved in the design of the scheme, many parameters such as incorrect ratios cannot be utilized in the project, and the expected cooling and ventilation effects cannot be achieved, seriously affecting people's lives. When designing, it is necessary to carefully and rigorously calculate various parameters and ratios, especially to eliminate errors in the calculation of heating system heat load.