The fresh air system is an independent air treatment system consisting of an air supply system and an exhaust system. It is divided into two types: ducted fresh air system and ductless fresh air system. The ducted fresh air system consists of a fresh air fan and duct accessories. The fresh air fan purifies the outdoor air and introduces it into the room, and exhausts the indoor air through the duct; the ductless fresh air system consists of a fresh air fan, which also purifies the outdoor air and introduces it into the room. Relatively speaking, the ducted fresh air system is more suitable for industrial or large-area office areas due to the large amount of work, while the ductless fresh air system is more suitable for home use because it is easy to install.

Ventilation principle：

The fresh air system is based on using special equipment to send fresh air into the room on one side of the closed room, and then exhaust it to the outside from the other side by special equipment, forming a "fresh air flow field" in the room, thereby meeting the needs of indoor fresh air ventilation. The implementation plan is: use high-pressure, large-flow fans to send air into the room from one side by mechanical force, and use a specially designed exhaust fan to exhaust it to the outside from the other side to force the formation of a fresh air flow field in the system. While sending air, the air entering the room is filtered, disinfected, sterilized, oxygenated, and preheated (in winter)