"The most important factor when I move into this little house will be to have radiant heat at the best possible monthly cost."

Wellll...Maybe I shouldn't have said the above in my previous post. I have looked into the mini-splits etc. IF I can insulate the slab from the top well enough and then carpet them I may be able to live with another system besides radiant. I guess it all depends on the operating cost and if I can be comfortably warm during the winter months. It's true that it would be nice to have heating and cooling. If financially feasable from an operating standpoint I think I still like radiant. With the hydronic system you can hook up solar too. Wouldn't take a large array of panels for this little place. I just want to be warm with cheap heat bills. The slab, however, presents problems in finding the right solution.