For that length i don t think you need to worry.
Ok to attack duct directly to roof vent.
The high humid air doesn t vent out of the house before it condensates in the duct and then runs back into the house causing damage.
Another biggie that i see all the time is sagging ducts.
Rafter vents or insulation baffles install in any rafter space to create narrow gaps that direct fresh air from the soffit vents to the peak of the roof.
In all cases the ducting needs to conduct the exchaust to the building exterior and needs to terminate in an animal proof vent cover.
I have never seen this before and at first thought considered it wrong.
Bathroom ventilation fan duct routing routing a bath vent duct down out or up through an attic or roof out.
Insulating the duct may also help.
You can find 4 in.
The vent should exit the building through the roof or wall at least 3 feet away from any other building openings and the vent cover which must not include a screen should allow dispersal of.
I d recommend venting out the gable.
Run a rigid vent from the gable wall to a point near your install and use a 2 piece of flex duct to connect the fan to the rigid vent.
You may have a bad boot around the roof vent that is leaking into the attic.
Loosely hold the wire and direct it through the ceiling drywall approximately where your vent pipe will go.
The official recommendation from the adc is that flex ducts should sag no more than 1 2 per foot of length between supports.
Today i saw a very creative way to vent bathroom fans.
Duct already wrapped in insulation at home centers.
The fan ducts were attached to a t fitting in the 4 inch abs main sewer vent stack in the attic just below the roof.
The owner s manual will usually tell you specifics on duct sizes and lengths.
Every register should be fed directly from the central unit or basement trunk line by its own duct.
The flex duct makes the bends easy don t kink it and allows the fan to be repaired from below in the future.
These specialty vents do not affect the.
Section of straightened coat hanger into a drill.
This article describes routing bath exhaust fan duct upwards through an attic or roof space or downwards through a floor or crawl space.
After sleeping on it i am having a hard time coming up with any legitimate reason it can t work and can t think of any problem it could cause.
If you can put an equal size duct inside the turn as shown below they say you re ok.
If you stacked registers on a single duct on second and third floors for instance all the.
First plan your route.
Or you may have a distance issue.
No you shouldn t use a towel or other absorbing material.
