Attic ventilation works on the principle that heated air naturally rises primarily utilizing two types of vents.
Extractor fan venting into attic.
Guys you could get a hole bored on your gable wall from the attic through too the outside ther are companies who specialise in hole boring get out the yellow pages then connect the extractor and the hole with a flexi hose.
A grille in each bathroom attaches to ducts which then fasten to a y connector at the fan.
Historically extractor fans were vented into the attic of the home.
In order to accomplish this the roof has to have a hole cut in it.
Duct already wrapped in insulation at home centers.
This involves running ductwork from the fan usually though an attic and out through the roof.
Although this isn t always possible in attic crawl spaces you should always insulate the duct to prevent condensation problems.
But while you can t have two fans with one vent you can make one fan and one vent serve two bathrooms.
For this to work properly air ducts must be properly sealed meaning no tears or holes that would allow moisture to escape into the wrong spots.
A bath vent fan duct that is too long may restrict air flow such that the fan is not functional.
Home builders learned from this lesson and began running exhaust ventilation ducts to the outside of the home.
A bath vent fan duct that is too short may violate the manufacturer s installation instructions may not work properly or may be drafty.
Bathroom exhaust fan duct length specifications.
This setup requires an in line centrifugal fan mounted in the attic drawing air simultaneously from both bathrooms see photo.
You can find 4 in.
Intake vents located at the lowest part of the roof under the eaves allow cool.
Here we provide specifications for recommended minimum maximum duct lengths for bathroom vent fans.
You should never exhaust the bathroom fan directly into the attic.
No you cannot vent your bathroom exhaust fan into the attic.
Options for venting a bathroom exhaust fan include best to worst.
Your attic is not a temperature controlled environment is never the same temperature as your living space and generally closer to the temperature outside.
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.
Bathroom exhaust fans perform an important function by removing excess moisture from your home.