porscha, Here are a couple of links to them. Maybe you will find somethiing in them. I thought about installing the hot water sysytem in my house out here I built, but at the last minute, and checking my account, showed me I could not do it on this house anyway, The next one for sure. That heat is so nice, not dry, easy, quiet, efficient, don't even know it is there, the list goes on. If you can afford it, by all means go with it..........