I own a wood stove that is rectangular and constructed of ¼ “ steel plate. I’m toying with the idea of enclosing it on the sides and back with concrete block 6” away and placing copper pipe in this space. I want to fill the void with sand between the stove and the block. The copper pipe would be connected to a radiant heat system. Does any one have any experience of info. On this?

Sounds interesting? But dry sand is a pretty good insulator, wouldn't most of your heat just go up the chimney?

I didn't think of that. Maybe I should use masonry to within 1/4" instead? What I'm thinking is that the masonry will heat up and radiate the heat all night. This way I don't need to get up in the middle of the night any more.

the thing i don't want to happen is for the masonry to get so hot that you can't touch it or someone gets burnt.

Some wood & pellet stoves have manifolds inside of them for the purpose that you propose. However, I believe that most of these are manufactured in Europe. Actually, it sounds like a good way for me to heat my future water storage tank when the solar is not getting it done!

I have looked at a number of ways to jerry rig a wood stove boiler, none of which have panned out. The stove has to be designed as a boiler, and U.S. manufacturers simply aren't interested. I finally solved my problem on eBay, or more specifically www.ebay.co.uk. Search for Aarrow SEB 20. It's built specifically to run radiators, baseboards or radiant. It puts out 70k btu/hr maximum, with 41k btu/hour to water. They also sell a stove with 60k btu/hr output to water. The SEB 20 costs about $1,700 at current exchange rates. I am paying about $700 to get it here.

You want to make sure that your state and local govt won't ask to see EPA certification. Two connection hiccups: The plumbing fittings are 28mm, and the air controls run on 220V.

I figure that the smaller stove will add a degree an hour to my radiant slab at 25k btu/hr, or enough to carry it overnight in a burn of six hours to 10 hours, and a termperature swing in the house of 65 to 75. You'll also need an indirect tank.It's safest to mount the tank higher than the stove and connect the two by thermosiphon. Both stoves have an automatic shutdown feature that reads the temperature of the return water.

Builditsolar has a bunch of sources and plans for storage tanks and heat exchangers. You'll also see many plans for masonry heaters, which is another way to turn a fast hot fire into lingering heat. But they take up a lot of real estate in your living room.

My stove is being crated up as we speak. If you act fast and you're willing to meet somewhere between NC and Philly, it's almost as cheap to ship one as two.

Thanks 4 the offer, but I'm still in the planning stages. I will probably be storing around 5k gallons of water. Lots. That s/b enough to get me through 3 days at design temp(-10°) in a Super Insulated house.

I was thinking that using a direct vent pellet stove as my backup heating device might be my best option. That way I wouldn't need a mod con, and all of my heat would come from one source(the storage tank), making all of the connections and switchover much easier. Now I need to find that stove!

Panelcrafters, here is a wood pellet boiler from Iowa that would add 50 degrees to your water storage in a single loading of 80 lbs burned over 40 hours. (assuming claims are legit.)
http://cgi.ebay.com/BAY-WINDOW-CORN-WOOD-PELLET-MULTI-FUEL-STOVE-FURNACE_W0QQitemZ350096199039QQihZ022QQcategoryZ41987QQssPageNameZWD1VQQrdZ1QQcmdZViewItem

mjunker, here is a bolt on water heater from Rutland Vt that the seller claims will heat 80 gallons of DHW/day.
http://cgi.ebay.com/Add-On-Hot-Water-Boiler-Wood-Pellet-Coal-Stoves-2985_W0QQitemZ120386540066QQihZ002QQcategoryZ115968QQssPageNameZWDVWQQrdZ1QQcmdZViewItemTeh The seller says it takes only five of them to run his baseboard heat. (!?)
Sorry to say,tinkering won't get you there.