Fresh air system can be installed after home decoration, because the function of fresh air system can effectively improve indoor air quality. For the newly renovated home, it is inevitable that there will be some formaldehyde and odor. In addition, the fresh air system can filter and sterilize the outdoor air through the fresh air main machine, and introduce healthy air into the room. In this way, the indoor air purification and oxygenation function is particularly fresh after being absorbed by the human body. But also good for family health.