Thanks for useful information and sharing your thoughts on this. It all makes sense. I did not think of a strong side wind BTW, good catch. I've also watched the video about fantastic fan vs. tiny nature's head's PC fan. I found a Youtube video of a guy who vented nature's head toilet through his tiny house floor, so if it works for him, it would work for me too. So I made the hole in the floor today, making progress, need to run wires now.