I have a Panasonic bathroom fan, about 75 CFM. I want to put a
backdraft damper at the end of the exhaust pipe to reduce cold air
coming in the bathroom. It is one of those spring loaded jobs and
says only needs .04 in W.G. pressure to open. I was going to put at
the end of pipe to the sophet for ease of installation, rather than
inline. Comments, or suggestions? I am also considering an inline
draft blok thing that is for dryer venting, which would be better, the
dryer one has one way flow louvers, yet the other is spring loaded
almost guarenteed to close!