When the range hood is not used, if the doors and windows are open, there will be air convection between the room and the kitchen lampblack channel.

Two, your unit lampblack emissions blocked or semi-blocked. Go upstairs and downstairs and ask if you have the same question. If there is your problem, it is that the flue in your unit is blocked.

Solution:

The exhaust pipe of the range hood automatically closes when there is no wind, which can prevent the oil fume from backfilling and rats.

Climb in. The principle is simple and the price is not expensive. You can buy it in the market.

Second, close the kitchen doors and windows when not in use, so that the kitchen becomes a relatively closed environment with no air circulation.

Third, find a property to clear the flue.