2 separate vents o the roof and yes, if you go straight up you will get condensation and dripping back down, it's not much so just a little sag in a pipe that will hold a teaspoon of water. It will leave and be replaced the next time you use it. Or run it longer when it is could outside.Installing new fans and there isn’t existing venting in attic to the outside. I’m going to install a vent on the roof and connect insulated pipe to the fans.
Two questions. Can I connect both fan vents together and into the same vent in the roof. Secondly I’ve heard you are supposed to create a “loop” in the insulated pipe. Where do I create the loop? What’s the purpose of it? I’ve heard it’s so condensation doesn’t make its way back or something. Sorry I couldn’t be more specific. A