I have an older home with a bathroom that has poor ventilation which
causes shower steam to coat the walls with moisture. In effect this
yields unwanted mould on the bathroom ceiling and other places like
tile grout and shower curtains. The differences between my bathroom
and a large petrie dish are begining to blur.
I have accepted the fact that I have to install an exhaust fan come
spring time
so I am begining to do a bit of research on the easiest method to
install an exhaust fan in an older home. I came accross this PDF
http://www.gov.ns.ca/energy/enerinfo/ventold.pdf which is a good start.
After reading this I realized that the most effective way to install an
exhaust fan is on an exterior wall, exhausting directly to the
outdoors. Does any one see any potential issues besides a proper way
to insulate? Looking forward to your replies.


Here are a couple of thoughts (I didn't read your link, so sorry if this is
repeated!)

Assuming your bathroom has access to an attic (i.e. if the bathroom ceiling is
the floor of the attic)...

If you have roof ridge vents and if you have access to the bathroom ceiling,
you can vent the fan near the ridge vents. Just take the tube from the fan and
mount the other end as near the ridge vent as you can. The theory is that hot
air rises and so most of the moisture will go out the ridge vent. This will
allow you to place the fan on an interior wall or the ceiling rather than an
exterior wall.

Maybe I am using the wrong term. By ridge vent I mean that your roof has one
long vent running along the peak of the roof.

Another tip, I tied the electric power to the fan to a light in the bathroom.
That way, any time the light is on, the fan is on. With the logistics I had,
it would have been a royal pain to make a switch for the fan itself.

One last thing, if you do vent out an exterior wall, look to see if you have
soffit vents. A soffit vent is located on the bottom of the eaves of your
roof. These soffit vents are the air intake for your attic. You do not want
to vent the steam of the bathroom near those soffit vents or you will be
pumping moisture into your attic.

Hope this helps.