Actually, I thought the same thing. The regular exhaust fan is going to pull much more cfm and out power the little fan in the roof vent. In my case, it did not. It's all about the path of least resistance. I have about a 1 - 1.5 inch gap under my bathroom door. The air primarily it pulled from there.
I did do the toilet paper test. I turned all the water off so I could open the toilet without the water running. When I "flushed" it with only the roof vent on the toilet paper actually lifts slightly. When I flush with the vent pipe fan on and the roof vent the paper is actually pulled down. And thats with the fan on low. On low you don't hear the fan running at all. On high you can barely hear it.
Now, I'm sure what you said would be true if you don't have a significant gap at the bottom of your bathroom door.
Also, I have know idea what cfm's my bathroom vent fan is, but it's pretty strong.
And yes, I guess I have nothing better to do than to see which way the toilet paper will go when I flush
* This post was
last
edited 07/08/08 04:02pm by seb503 *
View edit history
Offline
