Quote Originally Posted by muzz View Post
From what I have read about humidistats, it sounds like the setting on it has to be changed as the outdoor temp changes, correct?
Not that I know about, but maybe someone else knows better. The dehumidifier next to the sump in my basement remains at the same setting year-round, but it runs more often and longer in the summer when the ambient humidity is higher. I hope to get my bathroom project finished over the next few weeks, and I am assuming the dehumidistat connected to the exhaust fan will do about the same.

Quote Originally Posted by muzz View Post
With this short of a run, would it be a problem using an elbow right after the exhaust flange?
Not that I can see.

Quote Originally Posted by muzz View Post
... and then out thru the rim joist.
In your picture, that joist does not appear to be sitting on top of the wall. If not, some reinforcement should be added.