Luke Perry wrote:

Hi, I am a renter in a 1-bedroom apartment. I moved in last spring
and noticed that the apartment had a strong smell of mildew after the
home had been shut up during the day. I have been able to get rid of
most of the smell this past summer by ventilation and by cleaning.
The bathroom has a small exhaust fan over the sink but does not seem
to be able to absorb all of the moisture in the bathroom after a
shower. After a shower you can see water droplets coming down the
side of the walls and you can see moisture on the ceiling for up to 24
hours after a shower.

This has caused mold/mildew to grow on the ceiling and walls. I have
been cleaning and leaving the bathroom window open during and after a
shower but this combo does not seem to help much. I told my landlord
about this thinking they might be able to do something (stronger fan)
but they told me to try keeing the window closed during a shower and
let the fan work, and see if that helps. I think the fan vents up to
the attic, which might be part of the cause of the mildew smell that I
had/have in the apartment.

Is the landlord right? Does it work best to leave the window closed
and just run the fan by itself? If that does not work, should the
landlord try and remedy the situation or am I stuck with the problem?


thanks
LP

As bizarre as it seems, when I moved into my current house, I found that
the interior bathroom's fan merely returned the "exhaust" air right back
into the bathroom!

Whenever you exhaust air (bathroom fan, kitchen fan, attic/whole house
fan), replacement air must come from someplace. So if you keep the
bathroom window closed, the air will come through the door or, if
closed, the cracks/gaps around it, the window, electrical outlets, etc.
The only advantage to opening the window with the door closed is you
won't exhaust expensive "conditioned" air (heated in the winter, cooled
in the summer) from the rest of the apartment.

If it happens that the fan, window, and door are grouped mostly at the
end of the bathroom opposite the shower, the fan will do little to
exhaust air at the shower end. Airflow takes the most direct path. So
the fan gets its replacement air from the nearby window or door; it
can't draw it from the distant shower area because that area doesn't
have a source of replacement air. "Mix up" the air by using an
oscillating floor fan aimed at the shower area, with the overhead fan
running. And leave the fan(s) running for a while after leaving the
bathroom. (Maybe the landlord will install a timer switch.)

Try wiping dry the shower walls, floor and ceiling with a towel after
each use. Remove the towel from the bathroom, or the moisture it
absorbed will simply evaporate and return to the bathroom air.