At home, I'm considering installing a fresh air system, but I've been entangled in it, especially in the severe smog weather, and I can't open the window. What if I keep closing the window?

This is because fresh air has two values: 1. Oxygen transport and 2. A positive pressure environment is formed indoors to prevent polluted air from entering the room and play a sealing role. The corresponding question is: 1. Most families are too airtight to send oxygen at all, or because only a few people who have been indoors for a long time will not go to the degree of hypoxia, hypoxia usually occurs in such a crowded environment as classrooms; 2. To form positive pressure indoors, the air volume must reach 2 ~ 3 times of the indoor air volume, that is, a room with a height of 2.8 meters 100 square meters needs 560 ~ 840 cubic meters of fresh air per hour to achieve positive pressure effect. Generally, domestic fresh air fans can't reach this air volume, or can reach this air volume with great noise. The above two points, it is difficult to play the due value of the new wind. Yunjing was also studying the fresh air solution at the earliest, and found that the above problems were finally given up. Of course, there are still some problems in fresh air, such as heat exchange energy consumption of indoor and outdoor ventilation, which only purifies pm2.5, but cannot purify formaldehyde and bacterial viruses. Air purifiers also have the same fatal disadvantage, that is, the air volume is too small, and usually only the local environment can be purified. For example, the distance between Philips, Sharp, Du Ya and blueair and the air outlet of one meter, three meters and five meters will quickly decay to be invalid. In the end, Yunjing housekeeper solved the problem of filter life under large air volume and large air volume, so Yunjing achieved a daily air volume of 800, and the maximum air volume 1200, which can meet the demand of purifying the whole house with one machine.