For HVAC experts.....I have never seen this before: a bathroom ceiling exhaust fan which is routed to the return air duct in the attic. Is this a code violation? If not, is there any problem with ducting a bathroom exhaust fan into the return air duct to the furnace? Seems odd to me.
Bill P
Favorite Answer
NO NO NO NO, The Bathroom should be vented only to the outside. This air is HOT and Humid. Should Not be connected to the duct work at all. Quick fix, take the fan loose from the duct and let it go into the attic, until better weather, and get a piece of insulation and tape up the hole.
When weather turns nice route the vent to the outside. Keeping the run as short as possible.
rambin
Hvac Exhaust Fan
fishlakeguy
Most forced air ductwork's have a humidifier built in to add moisture, but it is usually only activated in the dry winter months to control static electricity in the home. Having an exhaust bath fan hooked up to a furnace sounds like a homeowner mistake, not done by a pro. Moisture would be blown into the non-operating furnace during the months when the furnace is not on, causing moisture related problems inside the blower/plenum, possibly mold or rust.
CaliGirl
Im not sure if it is a code violation, but it is different. I work for an air duct cleaning company, and we price bathroom exhausts seperate from other vents because they are not associated really with the normal vents. Sorry I dont really have an answer, but I figured I would throw something out there!
george b
The exhaust should be vented directly to the atmosphere. usually using flexible dryer type vent.Attach it to the exhaust on the unit and lay it parallel stretching it out a couple of feet.