Exhaust fans have been reserved in the walls, what exhaust fans should be installed, toilets and kit

First of all, don't listen to superstitions, any feng shui is also a lie. >>>More

Usually only a slightly larger exhaust hole is reserved, and at the same time, it needs to be treated to prevent rain from coming in and causing water to hide in the ceiling.

The bricklayer is right, it is true that the cement can not be blocked, because the cement is dry and the wall will have a gap, the connection is not firm, and it will fall off over time, he is right, when installing the flue, the void part is expanded with foam, and then the gap on the outer wall is coated with black glue, and the inner wall part does not need to do anything, and the kitchen cabinet is installed inside.

The toilet exhaust fan does not need a socket when it is installed, and it is controlled by a switch below.

It seems that there is a diameter of 12 cm - it doesn't matter if the tube is smaller, just hit the void with a blowing agent.