The difference between rated circulating air volume and clean air volume lies in different application occasions. Rated circulating air volume and clean air volume are two commonly used concepts in air treatment system, and they have certain differences. Rated circulating air volume refers to the air volume designed and calculated by the air handling system under the design and operation conditions. It is determined according to the requirements and design parameters to ensure the normal operation of the system. Rated circulating air volume is usually used to describe the total air handling capacity of the system. Clean air volume refers to the filtered and purified air flow that meets the specific cleanliness requirements. The amount of clean air is determined according to specific cleanliness standards and requirements, and is usually used in some special occasions or industrial applications, such as clean rooms, laboratories, medical equipment and so on. The requirement of clean air volume is realized by purification equipment such as filters to ensure that the discharged air meets the specific cleanliness requirements. In short, the rated circulating air volume is aimed at the whole air handling system, which is used to describe the overall capacity and handling capacity of the system; Clean air volume refers to the air flow that meets the cleanliness requirements after filtration and purification. There are some differences between them in concept and application, so it is very important to choose appropriate air volume standards and control parameters according to specific needs and scenarios.