No you cannot vent the bathroom exhaust fan into the soffit vents.
Bathroom vent air to the attic.
Bathroom fan vent code requirements include no venting to attic areas to help reduce mold or structural problems.
A single exhaust exits through the roof figure a.
This section notes that air exhausted from the bathroom must be sent outdoors not indoors to the same residence or indoors to any other dwelling unit.
This system is quiet too.
Bathroom vent fans are rated by how many cubic feet of air they can move in one minute known as the cfm rating.
A grille in each bathroom attaches to ducts which then fasten to a y connector at the fan.
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 mount a switch in each bathroom.
In addition to insulating your bathroom vent you want to avoid u shaped bends in the vent because this will allow condensation on the inside of the vent to drip towards the low point of the vent hose.
First you ll partially block your roof vent with the piping reducing the flow of cooling air through your attic.
The bathroom here is below an accessible attic so tom ran the exhaust duct across the attic and out a gable end.
If you vent the bathroom exhaust fan to close to the soffit vents which are vented plates under your homes outer edge and roof your home the air can be sucked right back into the attic from the soffit.
Bathroom exhaust fans perform an important function by removing excess moisture from your home.
This article series explains why bathroom vent fans are needed and describes good bath vent fan choices necessary fan capacity and good bath vent fan and vent duct installation details.
Bath vent fan installation building codes bath vent fan troubleshooting bath vent fan repair.
This setup requires an in line centrifugal fan mounted in the attic drawing air simultaneously from both bathrooms see photo.
Options for venting a bathroom exhaust fan include best to worst.
Second during cold winters you ll be blowing warm moist air onto a cold surface the roof vent and roof plywood.
It cannot move air to a crawlspace or attic.
Bathroom ventilation codes require a bathroom exhaust fan to vent to the exterior not the attic for health and structural reasons.
How to install a bathroom vent fan.
If you are sending warm interior air through the bathroom vent while attic is very cold then water may form.
While in the attic i would have that person measure the amount of insulation check for soffit ventilation and or gable end vents and sair seal any penetrations from the living area ie electrical plumbing chimney chases to reduce air leakage.
If you re tempted to vent your exhaust fan through an existing roof vent or even vent it into the attic don t do it.
To determine which size fan to buy for your bath multiply the room s square footage by 1 1.
