Exhaust Fan

[Dale]

Steve, you stole my thunder!

I was wondering why the need for such a large volume fan. A good quality bathroom fixture copes with the humidity from a steamy shower so it can cope with the humidity off a tank.
A low volume fan would also work better because of the nature of the humidity itself. A tank gives off a little humidity all the time (as opposed to a lot of humidity all at once) so you want to continuously vent the room (or on/off on a regular basis).
I didn't know about the CO factor but I'm also aware of the heat loss due to high air volume exchange. Unless you have a very drafty house you would need fresh air vents into the home, as steve suggested, with at least, very efficient heat exchangers. For every cubic foot of hot humid air expelled a cubic foot of cold air is drawn into the home and must be heated.
I've installed bathroom fans and connected them to humidistat's and they have worked well. Set to the desired humidity % and that's it. I've also heard of others using timers on the fans, on and off for a certain period each hour.
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Honda NA50