Hello all. Been doing some research on this but really not having much luck.
This winter I have noticed our dryer vent is forming condensation on the outside of it, close to the top where the pipe from the outside hooks to the flex metal duck from the dryer.
This is only happening when temps drop over night, and the dryer is NOT running. The dryer sits on a outside wall, so it is a very short run to exhaust it (maybe 3ft). The flap outside is staying shut, I have checked quit a few times on this. I have tried using insulated tape, where the flex duck and pipe connect which really did not help. Yesterday I put a 6" insulated (R6) sleeve on the flex duck (4")..... this morning I checked it and there was frost where the flex duck and outside pipe meet (still have the tape on there too).
I'm not sure what else to do at this point.... Looking for some idea's and suggestions on how to eliminate this annoying little problem.
Convection process is causing the frosting. Mine did that last week, because the temp in the basment is around 58-60, and the outside wind chills were below zero. I ended up placing some more insulation in the joist bay against the sill joist to help insulate the section of my dryer vent, and that helped for mine.