I'm not quite sure what a heat fan is, but it shouldn't bother him. I wouldn't point the heater towards the tub, it will really heat up the tub and your fan won't adjust itself when it gets too hot in the tub. If you are going to use it to heat up your room, no problem. In the winter months I use an oil space heater to keep the temps up in the room so I can keep the cool sides of my tubs up to 80. It did kill the humidity in my large tubs so I had to do some tweaking.