put baseboard in or quick track with radiant

I don't understand, are you suggesting I remove the new floor and install radiant heating.
Or glue aluminum quick track to the bottom of the slab and buy a boiler for hot water? I have a heat pump for heat.

Baseboard? what will a baseboard heater do to the temp of the slab? The room is not cold only the floor temp.

Ok I re-read your post. Pick back up the plywood, level the floor out. Then use quick trak on top of the cement. Use cement nails for the quick track or viega makes same product called climate panels. Run pes though em. then either get a seperale 50 gallon water heater . use the quick recovery from ao smith. pipe it up as a boiler with a stainsteel pump. You don't kneed another poiler just a water heater. If your good and you can use a desighn off radiantfloor.com you will be fine. Don't forget your spiral vent, potable expansion tank, if used for domestic also. and a back flow preventer.

Thanks but I don't want to start over, I am looking for a fix without tearing up my 32x24' living room again. The sub floor has bat insulation, Im just looking for a efficient way to retrofit some insulation or heat to the slab.
thanks

I'd glue 2 or 3 inchs of XPS but it will not get you as warm as the crawl space area. Your heating idea won't either. The only thing that would is supplemental radiant heat - electric or pex.

You might get 1/2 way back to the crawlspace temperature with insulation - just my guess. Maybe it will make it unnoticeable - that is why I'd try it. I think getting the other idea right would be very tricky (heating the cavity under the slab).

The insulation is just a no brainer and there is the 30% tax credit to think about. If the bottom of the slab is uneven (and I suspect it is) then I'd do spray foam. You really want r-13 at least...

The crawl space under the slab is surrounded on all 4 sides with 4" block, except for 2 vent holes and 1 2x3 opening. Also there is only dirt on the floor.

This I don't understand.
"You might get 1/2 way back to the crawlspace temperature with insulation." The top of the slab is already at least 25 degrees above the crawl space temp.
"I'd glue 2 or 3 inches of XPS but it will not get you as warm as the crawl space area."
When the outside temp is 40 for instance the crawl space under the slab is about the same temp. So if I add the XPS or insulation to the bottom side I should be able to keep the slab itself a few degrees warmer than the crawl space under it, do you think the underside of the slab is colder than the crawl space?

The slab is pretty smooth on the bottom, I have no idea how they built it, but the bottem side looks as smooth as the top of any slab.

I can buy DIY spray for about $700 that would give me 2 inches of R7.4 per inch. I haven't called a local company yet. The piers would still be ground temp I guess.

As far as the air idea I was conceding making a couple inches air tight under the slab and hooking the heat pump into one end with a 3" duct and exiting the other end back to the return air. Its all under the house.

Without a doubt the insulation - that concrete slab has thermal mass. Once you break that conductive loss with the insulation, you will see a big difference. Slab insulation when used on the edge or underneath is typically 1 or 2 inches. More is better, if you can get two inches of spray foam = R-14.8 or so you will be very happy with the end result. Think of the foam coffee cup - you put 100 degree coffee in your hand separated by an 1/8 inch of foam...

The heated cavity and heat strips with out insulation will heat the surrounding air just as well as the slab - so you will need to insulate that anyway.

hth
Andy

Andy:
thanks I think the insulation would be easiest also. I could suspend foil backer board and fill the space with R13 bats if I cant find a local company that will do spray foam.

What worries me and the reason I haven't do it yet is I had a metal building built 3 years ago with 2x4 16 on center and insulated it with OSB interior walls. Insulated the ceiling and insulated the floor with R13, the floor is 3/4 osb with vinyl tile, the whole thing was wrapped with that silver backed bubble wrap so its air tight. Its sitting on concrete and the tin comes within 1/2" of the ground. I have a split system heat pump and it works great but the floor temp is not even close to the air temp, when its down below 40 the floor is really cold and it has plenty of insulation.

And probably warm in the summer, you just don't notice it as much... :O)
What your building lacks is slab edge insulation - the slab edge is a major energy loss point. The best thermal image could find on the web is not great - but shows the condition.

a paper on the subject
http://www.khhpc.com/Portals/0/Pdfs/News%20Publications/Bottom%20of%20the%20Envelope.pdf

some diagrams and image
http://1510365blog.wordpress.com/category/latest-1510365-tips/276-insulated-slab-edge/

You may still have the heat loss point on your project, unless you can insulate it.

hth
Andy

I really want a thermal camera but not at $4k.
I could get to the edges but they are setting in 4" block, and I cant do anything about that. Also the columns are double 8" block so I will also loose hear from them.

It looks like the easiest and cheapest is.
1. put plastic on the ground.
2. wire up 1/2 foam board and top with R23 bats no paper.
3. try to insulate the edges.

The R rating for batts was made in a laboratory, not in real outdoors situations. Wind and air moving are going to reduce batts efficiency. I would only use spray foam and hard foam panels. Fiberglas batts are never as good as their laboratory ratings would lead you to believe, not even in indoor situations like attics and exterior walls (where there is barometric pressure, wind, moving air). Maybe in basements...

makes sense but the bats will be sealed on the top with the slab and on the bottom with foam board and all 4 sides with block walls. No air should circulate. I expect I can do the job for $150 as opposed to $1100 for spray foam.
I would really like spray foam but a diy kit cost $800 and I could maybe only get 2" on the slab bottom, none left for the piers or walls. So I would have to call a company to do it.
I will call tomorrow and see but I bet its $2000

the slab is under the house, has a block wall on all 4 sides, if I hang foam about 6" under it and fill with insulation and seal around the piers with foam there is no way air can get inside except through the pores in the block. There is a vapor barrier on the top of the slab in the LR and will be one on the ground 4' under it. The construction would be similar to building a basement wall out to add insulation except in reverse.
House, vapor barrier, slab, insulation, foam board, outside confined space, ground. I could also seal up the underneath side and add a de humidifier if necessary.

I finally decided on spray foam. I can get a 605 lf kit for about $650 shipped. I should get 2" if I'm careful. I measures the undersides and position of the piers and the piers consume about 30sf. 1" is R6.4 - R7.2 I plan on spraying 1" on the bottom of the slab and about 2" around the top of the piers and block walls. Then using whats left to build it up, I should get at least 1.5" up to 2" on the slab bottom. I found the bottom of the slab is covered with what looks like roofing paper. I cant pull it off. It looks like they may have formed it up with plywood with roof paper on top so they could remove the plywood.