From: "Tomes" 
Newsgroups: misc.consumers.house
Subject: Re: Bathroom fan - how long to leave on?
Date: Fri, 03 Mar 2006 17:19:20 GMT

"Jonathan Kamens"  wrote in message
news:du6t0n$15a$1@jik2.kamens.brookline.ma.us...
> "Tomes"  writes:
>>> I dn't think this is a problem, because the humid air is hotter and
>>> rises naturally, and because humidity diffuses quickly in air in any
>>> case.
>>LOL - the point of the above text was addressing how to best remove the 
>>air,
>>not whether the air was good to have around.
>
> Perhaps I was not clear.  Let me try again.
>
> Since the humid air rises naturally, it rises to the ceiling
> and is exhausted by the fan even if the bathroom door is open
> and thus airflow isn't strictly bottom-to-top.
>
> Since humidity diffuses quickly, even if airflow isn't
> strictly bottom-to-top, the humidity in the lower air diffuses
> quickly into the upper air and is thus exhausted by the fan.

Ah, OK, I see your angle now.  Makes sense.
Tomes