Historical source of fresh air system

As early as 1906, when studying air and human health, Mr. Al, an indoor environment scientist at the British Institute of Natural Environment, found that the index of indoor air was very different from the content of air components in the outdoor natural environment. This change in indoor and outdoor air quality had a great impact on human health. He took the lead in proposing that indoor and outdoor air can reach a relatively close degree through effective ventilation, and that air is the first element of human health. After years of research, he invented the method of forced mechanical ventilation to realize the replacement of indoor and outdoor air, and named it fresh air system.