Fantech recommends a minimum of eight feet of insulated flex duct between the exhaust inlet register or grille and the fan motor.
Bathroom exhaust fan vent pipe.
Surprisingly bathroom fans are not required by some building codes.
In those areas ventilation in bathrooms is required but it can be from a window or fan your choice.
Ceiling fans vent either into the attic or outside through the roof.
Ductwork is what will connect the fan to the outside.
All municipalities have different requirements but some do not draw a hard line on requiring exhaust fans.
Required bathroom vent fan ventilation rate in cfm this ventilation code specifies a bathroom exhaust airflow rate for toilet rooms and bathrooms not served by a window of adequate size of 25 or 50 cfm ft for hotels motels resorts and dormitories and a slightly more modest 20 50 cfm for private dwellings.
Another consideration to think about is the placement of your fan.
In order to make the vent fan as quiet as possible mount the fan itself as far as possible from the intake register in the bathroom.
The basics of venting a bathroom exhaust fan the bathroom exhaust ventilation fan disperses air through an opening in the fan housing which is usually 3 inches in diameter and ideally faces in the direction of the ventilation system outlet.
When venting a bathroom exhaust fan make sure to vent the air to the outside rather than into your attic where it can cause mold and mildew to form.
You may be able to configure a short route.
This setup requires an in line centrifugal fan mounted in the attic drawing air simultaneously from both bathrooms see photo.
The company does not cite a maximum exhaust duct length.
There are wall mount exhaust fans as well as ceiling exhaust fans.
You can find 4 in.
If you have a bathroom with a separate enclosed toilet you ll also need an additional fan for that space.
Through the roof or an exterior gable wall.
Options for venting a bathroom exhaust fan include best to worst.
No matter the location of the bathroom you can vent the exhaust fan through the wall.
The location of the bathroom will determine how extensive the ductwork will be.
But while you can t have two fans with one vent you can make one fan and one vent serve two bathrooms.
Although this isn t always possible in attic crawl spaces you should always insulate the duct to prevent condensation problems.