Air-Conditioning in operating rooms causes stuffiness and is common compliant for doctors and nurses, especially in small operating rooms where the usage of Halon is 500ml/h.

When the new wind blow attains 1200m3/h, the concentration of Halon can be maintained 500m3 (1200m3 = 0.4ppm, which is just lower than the maximum allowed concentration of 0.5ppm)