I am basically building a glorified garage - 30 x 42 - planning on converting it into a small home in the next few years, but need to live in it as a large open space for now. Located near Brainerd, MN. I'm going to put the tubing in the floor for infloor heat - but don't know that I can afford all of the other components right now. What would be a good "clean" and affordable way to heat it this first winter.