Fireplace stone facade for heat storage?

[Stew]

We will be starting to build the natural stone facade for our main floor fireplace this week. We have radiant floor heat in the basement and on the main floor, electric boiler for now, Tarm or EKO in the future (Too busy with construction now to worry about the downdraft boiler now.) I was thinking of putting pex sandwiched between the 4" block and the stone to use for future heat storage, sort of like a masonry heater except the heat would be produced by the wood boiler. The fireplace is an EPA certified zero clearance Valcourt FP-8. The stone will also serve as some passive solar storage as it gets a few hours of
direct sun in the winter. Has anyone tried this kind of thing?
Stewart

 

[Nofossil]

It wouldn't hurt, but you can't store very much heat that way - stone is a poor heat storage medium compared to water. If you have a truly massive amount of stone it can be effective at limiting temp swings. Looks nice, too ;-)

 

[heaterman]

This is what I did using Viega's Climate Panel underneath "fake" stone on a gas fireplace enclosure. It works well. The surface of the fireplace runs about 10-11* above room ambient. You can definitely feel it when you walk past the fireplace. I simply tied into the same manifold that was running the Climate Panel on the floor and let the fireplace run off the same control and circ. This particular house heats with 115* water at a design temp of -10*.

(broken link removed to http://healthyheating.com/Newsletters/Radiant_Walls.htm)