David, I thought about that but it would not be that helpful as my bedroom is mostly over the tires and rear portion of the bus and not over a lot of bay space. The bathroom has cabinetry on one wall then the tunnel goes through the middle the the toilet and shower takes up the rest so the only floor space is over the tunnel. It would only be efficient if it were installed internally before the finish floor was put in. If I ever replace my front room flooring and bath I would consider putting it down the center.
I may have a built in advantage over most of you. I want my bedroom kept at the same, approx, temp as the outside. I don't see anything lower than 20 degrees here and I think I would have to amend that if I were up in Canada or Wy. The bathroom? Thats warm as toast. Point being I think is I would be easier to heat with less. Oh, and by the way, I have a 10 inch thick Down Comforter that is on the bed 9 months out of the year and the windows are open wide regardless of rain storms and wind. Like sleeping outside on the porch....I LOVE it. Wifey has learned to love it also but it was a struggle for her at first. The dogs? They are in full mutiny at this time of year and resist comming out from under the covers to even take a walk. Man's best friend...yeah...sure!Warmly,John