Why are N95 masks equipped with valves?

Because of the filtering effect of the mask, the air entering the respiratory tract is not so smooth. Therefore, when this mask is worn on our face to protect the nose and mouth, people will feel uncomfortable after a long time. Generally, there is some resistance when inhaling, and I feel that I can’t breathe in, and the inhalation is insufficient. When I exhale, it is difficult for airway gas to be discharged into the air, and there is always hot air on the face. For example, people who wear masks wear glasses in winter, and frequent heat will cause a layer of fog on the glasses, which will make people feel very uncomfortable.

So someone designed a mask with a valve. The mask has a valve on it. This valve is one-way, which means that when air enters our respiratory tract, it must pass through the three-layer structure of the mask. But the valve of this valve opens when you exhale, so the exhale is discharged into the air smoothly. Therefore, people who wear this kind of mask will feel comfortable immediately, because exhaling is easier. This is the origin of valve masks.