Thermal Mass retrofit for wood stove

Chas again with another idea I am working on, I have a Jotul F 50 TL Rangely which is a non-catalytic wood stove which if burned correctly is very clean with one drawback without thermal mass it uses a good amount of wood. I have been brainstorming of ways to build thermal mass around it to help store more heat, the firebox is firebrick lined which helps the clean burn but I have a good amount of heat going up the chimney which is insulated stovepipe.  Because of the design of the house, it would be very hard to build a rocket mass heater in the house I am thinking of building one in the barn however if I can find the time. Thanks in advance for any ideas, Chas.

Just dry stack rock out around your stove.

This obviously is not how my house looks today by the way...

Travis, Thanks that's what I kept thinking I would do I have tons of rock around the yard I will put them to good use, as long as the Wife approves of a pile of rocks in the living room. I will at some point send a picture of how I get the wood from the woodshed into the house I build roads so I have a wood shute made from ADS 2-foot dia. running from the shed to a box outside the window with the window next to the stove works quite well, Chas.

Chas de Geofroy wrote:Travis, Thanks that's what I kept thinking I would do I have tons of rock around the yard I will put them to good use, as long as the Wife approves of a pile of rocks in the living room. I will at some point send a picture of how I get the wood from the woodshed into the house I build roads so I have a wood shute made from ADS 2-foot dia. running from the shed to a box outside the window with the window next to the stove works quite well, Chas.

Just be sure your house can handle the weight. This is a concrete slab foundation so weight is not an issue.

Travis Johnson wrote:

Chas de Geofroy wrote:Travis, Thanks that's what I kept thinking I would do I have tons of rock around the yard I will put them to good use, as long as the Wife approves of a pile of rocks in the living room. I will at some point send a picture of how I get the wood from the woodshed into the house I build roads so I have a wood shute made from ADS 2-foot dia. running from the shed to a box outside the window with the window next to the stove works quite well, Chas.

Just be sure your house can handle the weight. This is a concrete slab foundation so weight is not an issue.

One of the BIG PROJECTS still to be done on this house is to install a wood stove. The plan is to get an EPA approved stove with as high an efficiency as we can afford. To that I would like to add some thermal mass, but we’re limited on that. We are on a crawl space, so a huge amount of thermal mass around the stove is not possible unless we reframe the floor and build a support up from the ground below. Our physical limitations might make that problematic, as does our budget (we probably cannot afford to hire out a project like that).

While not a huge amount of thermal mass, I have been pondering using cement board and tile under and behind the stove, floor to ceiling. That would allow us to use single wall pipe up to the ceiling and still sit closer to the wall, thus freeing some of the chimney heat to radiate into the room. It would also allow a very modest amount of thermal mass to absorb some of that heat. We have laid tile before (though never up a wall) and so we could probably tackle this project.

I do wonder if tile, mortar and cement board contain enough mass to make this worthwhile? And, does use of a single wall stovepipe adversely affect efficiency of a high efficiency stove in any way?

No, it would not adversely affect the performance of your stove, as long as the pipe is inside the home. If it is outside, then it would considerably effect the draft which could be problematic. I doubt it would be worth doing from a mass perspective, but I am unsure if it would be worth doing from a cost standpoint.

You would save on the high cost of triple wall pipe, but that would be offset by the cost of the cement board and tile. So I am not sure.

If looks was not that big of a deal, I would just buy a roll of 24 inch aluminum trim, then some fiberglass electric fence insulators, and some long screws. In that way you could stand the aluminum an inch or so away from the wall, then drive the screws through the aluminum, then through the insulators, and into the wall (studs).

Here's what we did: [url=http://geopathfinder.com/Masonry-Stove.html]

Thanks for your thoughts, Travis. Appearance does matter, as does cost. So this is a balancing act, to figure out what will give us the heat we want, lowest polution possible, look attractive, be affordable, and not cancel our home owners insurance. We also have champagne tastes and a beer budget! 😸