This will help to avoid air leakage.

The output sleeve of the device should be connected to the ventilation system, be sure to take care of the tightness of the connection. This will help to avoid air leakage. In this case, it is best to process the connection using silicone sealant. The place of fastening of the ventilation box can be noted using the level and pencil. To do this, attach the hood on the wall and start marking the required places.