Clothes dryer causing humidity problems in garage - would extraction fan help?
You need to vent the dryer to the outside. Blowing moisture from your dryer, or bath vent, into the attic will cause mold and rot in your attic, possibly water damage on your walls and ceilings when it condenses, and may eventually cause roof damage. As a plus, venting the dryer outside can shorten your drying time and save some energy ($$$).