Published on September 29th, 2013 | by Henri0
Installing radiant heat in crawl space
Q. I live in a 25- to 30-year-old, 1600-square-foot ranch. I have been trying to improve the energy efficiency over the two years that I have owned it, including adding insulation and replacing windows.
One room is the width of the 2-car garage, located at the back of the garage and about 10 feet deep. It has just a crawl space under it and is on a different zone on the forced hot-water baseboard heat. I am thinking of converting to radiant floor heat as everything is exposed in the cellar. Can I do that in the cold crawl space? How would I insulate and protect it in there?
A. I don’t see any reason why you can’t convert to radiant heat in the crawl space. If it is properly installed by experienced contractors, it should work fine. But select the contractor carefully. I have seen an installation where the contractor used nails and staples to fasten the radiant tubing in spite of the fact that the manufacturer expressly warned against it. The tubing was drooping and leaks were not far behind.
The tubing needs to be straight, held about 1-inch below the subfloor by approved fasteners that are spaced according to the instructions to avoid sagging. Reflective pans are installed below the tubing, and the rest of the floor joists’ depth is filled with fiberglass of the recommended R-factor, considering the make-up of the floor above. The tubing should also be installed so that it avoids as many concealed couplings and joints as possible. This is not a job for amateurs.by