I have an Air King 100cfm exhaust fan next to the shower. It was originally installed using 4" flexible insulated duct through the attic and out the roof and every time I got out of the shower the fan dripped water down on my head. I was frustrated and replaced it with 4" rigid insulated smooth wall ducting. From the fan I started with a 90 deg adjustable elbow which is connected to a 30" straight duct at about a 60 deg angle that attached to another 90 deg adjustable elbow (this elbow connects to the roof vent that has a damper). After doing all this work nothing has changed. The ducting is taped sealed and insulated so I completely confused. The fan works great without ducting attached I feel it push a lot of air into the attic. the fan is covered with loose fill fiberglass insulation so it shouldn't be to cold and causing it to condense. The overall distance for ducting is about 4 feet and its all smooth wall now so Im totally confused about the next step, please help!