[sr]

Bruce, I removed my fan and sure enough the vent was above the insullation and the fan vented into the plenum. I removed the insullation around the vent. I then purchased some flexible 1 1/4" plastic hose and cut it to approximatly 10 inches and stuck it inside the plastic pvc pipe/vent. I then used your idea to put a plastic bottle the size of the fan opening and taped it to the fan. The mouth of the bottle fit exactly inside the flexible tubing. I then re-installed the fan, Turned it on and went to the roof and felt a good flow of air coming out. One problem I had was that the vent came down right above the air conditioner ducting. I had to smash the duct a little to get the hose inside the vent.There also is another vent that is about 3 feet away from the other vent. I took the top cap off and it also vents into the plenum above the insullation. I think I will call DRV and ask Kent how the vents are supposed to work and see what their thoughts are.

Thanks for the insight. My exhaust should be much better. Now that we have a better understanding how the venting works it will be curious to see if there is a condinsation issue going forward.