> For an inelegant temporary solution try wedging the exhaust fan's
> one-way valve open.
I don't believe it has a one-way valve. It's a fairly small fan, probably
100 cfm, and uses a squirrel cage blower with a small shaded-pole motor. No
way to make it run backwards, either. For rodent protection, I believe
there is a screen in the cap on it's "chimney", but they couldn't get
through the vanes in the blower anyway.
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