Regarding the exhaust attic fans one would put in the end of an attic in a
Colonial style house:
I see many of them have louvres that open automatically when there is an air
flow thru them.
Why would one want louvres at all ?
The only reason I can see is to keep (some of) the rain off the electric fan
Is there any other reason ?
Sure seems like it would be better to have a constant air flow thru them in
the winter, e.g., when the
fan is not working.
What am I missing here ?