1. First of all, we should check whether the flue of our home is installed flue check valve. Flue check valve, simply put, is a kind of gas flow by the force of the automatic opening and closing of the valve, not only can play a role in connecting the pipeline, but also to prevent other people's home exhaust and fumes back into their homes.

2. The kitchen door or window is open, the hood work, if you do not open the doors and windows to form convection, then the fumes will not be discharged. When the hood stops working, without opening the doors and windows, then the air pressure in the room will be less than the air pressure of the flue, which will lead to the situation that the fumes discharged from other people's homes are backed up into your home.

3. The power of the hood

If the downstairs is catering, resulting in fumes back into the home, then first need to check whether the power of the hood of their own home up to 500m?/h, because the power of the catering hood is 2,000m?/h, both the discharge rate or emissions, are far greater than your home and faster.