I'm going to do it on ours. We had all of the openings covered during construction, but some had to be taken off when they were working on some flooring, and now you can see tons of dust in there. So before we put in carpet they are going to come clean them out.

Insultarp appears to just be a ½ inch foam insulation with a vapor retarder and a layer of aluminum foil. IMHO itÂs just an expensive vapor retarder. I would use 2" of Styrofoam even under an unheated slab but I once discovered a contractor desperately trying to finish a pour so I wouldnÂt see that he had omitted it so IÂm not sure it has ever gotten into one of my projects. You donÂt need a PhD to know that more heat will move to the colder side of the slab and that "radiant heat" doesnÂt exist in a concrete slab or the ground or insulation for that matter. Where does this nonsense come from and why does anyone believe it? On the Insultarp website they claim (twice in two successive paragraphs), "In a heated slab, Radiation is responsible for 93% of the heat traveling downward." Heat energy in a slab doesnÂt know up from down and radiant (infrared) energy needs an air space to exist much less move anywhere so in reality 100% of the heat moving downward through a concrete slab is being "conducted". To slow it down add some insulation.

You will need an air handler (blower fan) and cooling coil for your AC. It is not much different in cost to add the furnace vs just the blower. I think it is a good idea as you have laid out. As I understand what is proposed....Since your AC isn't ducted to the basement, I am assuming that this heat won't be either. So no difference in ductwork, so nothing to credit.

You will have to do some careful demo to see how its done. Educated guess says everywhere there is a long crack is where the pipe is. Also guessing copper pipe was used considering longevity and time period. May be nearing end of life in my opinion, consider replacing/rerouting pipes while it is opened up. Does little good in the ceiling and walls, it is better off in the floor (heat rises).