I want to install a fan in the bathroom. I have two choices to vent it, one out through the soffit which is difficult to access due to the roof pitch, or two out through the end wall of the attic. What is the max distance that I can run the ducting if it is 3 inch diameter? This would be the easier solution but it would mean a straight run of 14 feet.
Answer:
Fourteen feet is not a problem. All you'll have to do though, is place bats of R-28 insulation over the duct right from the fan housing to the wall it goes through.
