Letting the fan exhaust into an open attic will cause moisture buildup on the underside of the roof.
Bathroom exhaust fan through roof.
The best exhaust fan venting is through smooth rigid ducts with taped joints and screwed to a special vent hood.
I prefer to run a bath vent to outdoors via a horizontal line that goes across an attic and out through a gable end wall or one that vents down and outside through a roof overhang or soffit.
For bathroom over 100 sq ft use a large or exhaust fan to circulate the air.
All municipalities have different requirements but some do not draw a hard line on requiring exhaust fans.
Avoid venting through a soffit vent or ridge vent.
Venting through a roof vent or exhausting them in the attic could cause moisture problems and rot.
The master bathroom and the 2nd bathroom vent through the roof and through the same opening.
The warm air will exhaust out the duct and enter back into the attic through the soffit vent or ridge vent.
A grille in each bathroom attaches to ducts which then fasten to a y connector at the fan.
And under while medium bath fans work well for bathooms 70 to 100 sq ft.
Because the fan is in the attic you ll hardly hear it.
Ceiling fans vent either into the attic or outside through the roof.
The 2 pipes one a 4 master and the other a 3 2nd do not go through the ceiling but into a common box that goes through the roof.
This system is quiet too.
Wall mount fans are mounted on an external wall of a home and are used if there isn t a way to vent through the roof as in the case of a bathroom on the first floor of a home.
If you have access to the attic the fan can vent either through a gable wall or roof.
The 2nd bathroom vent drips on the floor and is ruining the ceiling.
In those areas ventilation in bathrooms is required but it can be from a window or fan your choice.
In all cases the ducting needs to conduct the exchaust to the building exterior and needs to terminate in an animal proof vent cover.
Look for the special fans starting at 160 at heating cooling equipment.
Surprisingly bathroom fans are not required by some building codes.
Bathroom ventilation fan duct routing routing a bath vent duct down out or up through an attic or roof out.
A single exhaust exits through the roof figure a.
Small bath fans provide adequate bathroom ventilation for 79 sq ft.
There are wall mount exhaust fans as well as ceiling exhaust fans.
The first step in figuring out how to install a bathroom fan is cutting a hole based on the size of the fan you need.
This article describes routing bath exhaust fan duct upwards through an attic or roof space or downwards through a floor or crawl space.
This discussion is now found at bathroom vent up through roof.