On Tue, 6 May 2008 01:26:14 -0400, "MiamiCuse"
wrote:

I am trying to size my bathroom exhaust fan. Most sizing chart says to use
the SQFT size and multiply by 1.1 to get the CFM if ceiling is standard 8'.
So for a 10x10 bath = 100 SF it would be 110 CFM.

However when you use finish using your bath typically you have the fan on
and the bathroom door open right? So it's drawing the air in the bath PLUS
the air from outside the bath. Would it be a good rule of thumb to
overshoot the 1.1 multiplier? or that already have a safety factor
built-in?

Thanks,

MC



There's nothing wrong with a more powerful fan, other than the noise.
The faster you can dry your shower, the less chance of mold/mildew.