I like that idea for the internal fan, didn't think about using the drain. I suppose $90 isn't too bad since they want over $80 for the store bought outside fan set up. You will find your outside fan will probably run all the time as that pipe is always hot as, switch it off at night but keep an eye on your temp knob as under 3 at night will turn it into an ice box usually. Very tidy set up.........you may affix a Star to your forehead.