Since a bathroom vent fan should run for 10 15 minutes after you finish your shower to remove all the moisture consider a fan that cuts on and off automatically using a moisture sensor or replace the wall switch with a timer.
How to vent a bathroom fan through the wall.
At first measure the length and width of the fan accurately.
Drive nail through house wall from attic.
This will serve as a reference point for positioning the wall cap.
Depending on the location of the bathroom it may be easy to vent the exhaust fan through the roof.
Keep the run of vent pipe as short and straight as possible.
Note that the bathroom vent fan must always exhaust to the outdoors.
If you vent through the roof condensation will drip back into the interior.
Behind a gable vent.
Now take the maker and scale to draw the exact size on the wall.
Through the roof or an exterior gable wall.
Options for venting a bathroom exhaust fan include best to worst.
To improve venting and reduce air resistance in the vent pipe.
In this video this old house general contractor tom silva explains how to vent a bathroom fan.
Never allow the duct to simply blow into an attic crawlspace or other enclosed area.
In addition to low profile bathroom exhaust fans there are also through the wall ventilation fans which you can install in your bathroom.
From outside use 4 inch hole saw to cut hole for wall cap.
It eliminates the need for routing ductwork through the house and these fans usually dry the bathroom more quickly.
Then write these measurements on a paper.
Almost all fans are square or rectangular in size.
Other venting options includes running the duct up through the roof or down through the soffit.
Behind a soffit vent.
A 3 or 4 inch duct connects to the outlet on the fan housing and runs to a side wall or to the roof and connects to a vent cap that allows the.
I recommend that my clients vent their bath fans out a gable wall if at all possible when not using an hrv or erv that is.
After buying the fan carefully start to install a bathroom vent through a wall.
This involves running ductwork from the fan usually though an attic and out through the roof.