In my new home, on the second floor, the bathroom fans goes outside and under the roof, so the output is upside down.
They installed the type of vent with a flap that, normally with gravity and perpendicular to the ground, stays shut but since they are installed upside down they stay open all the time.
I thought about a vent like we have in the kitchen's fan, a valve that opens only when air is pushed one way, but not sure if there are any off-the-shelf for bathroom fans.
We hit -20C the past few days and the cold air was pretty apparent.
Anything I can do here?