Add stratification chamber to conventional wood stove

Howdy. Relative newbie to permies here. Loving what I've found so far.

Apologies if there is a post addressing this already.

I plan to build a RMH (batch box style--I think) in the next 2 years or so (hopefully 2026). Currently, we are feeding a behemoth Ashley wood stove in our basement many times a day and the temp drops about 10 degrees F overnight. The insulation in the house isn't great currently--will be addressing this over time. I'd like to do something relatively quick to reduce our firewood usage if possible (or at least capture more of the heat before it exits the flue) while I make plans for a better system installation.

My questions for yousss:
1. Is it worth adding a large stratification chamber to the conventional wood stove in my basement to capture heat and distribute over longer periods of time? Or is the stratification chamber only useful with the RMHs because of the high temps they achieve in the barrel?
2. As I consider future options, does anybody have reasons for or against trying to use my current wood stove as the firebox for a batch box RMH? This might be a wild question, but I figured I'd throw it in here in case anyone has some input.

Some relevant info:
Basement SF: 618
1st Floor SF: 1065
2nd Floor SF: 404
We are currently renovating the 2nd floor which is uninsulated (2nd floor deck is insulated, but not helping as much without wall and roof insulation yet)

Pics of current stove attached.

Thanks to you all in advance!

Justin Henney wrote:1. Is it worth adding a large stratification chamber to the conventional wood stove in my basement to capture heat and distribute over longer periods of time? Or is the stratification chamber only useful with the RMHs because of the high temps they achieve in the barrel?
2. As I consider future options, does anybody have reasons for or against trying to use my current wood stove as the firebox for a batch box RMH? This might be a wild question, but I figured I'd throw it in here in case anyone has some input.

Justin,

Is your objective to heat the basement or entire house?

1. If the exhaust temperature is high, probably a barrel could be added. I specifically said "barrel", because building a masonry bell would not make sense in this case as the bell takes more labor than a proper firebox.

2. How the current wodstove would become a BBR firebox?

You pretty much nailed it with your first question. A woodstove and an RMH are two very different animals. An RMH is a system and the stratification chamber (or mass bench, if it's an older design) is a component whose function is to accumulate the thermal energy released in the combustion chamber, store it in the mass, and release it to the space that's being heated. Very few woodstoves approach the level of complete, super-efficient combustion that you get with a properly built RMH, and so they aren't really suited to having this extra volume and mass inserted into the picture.

At best you might get a little extra "thermal flywheel" effect, but the downsides are several. You will change the draft of the stove, possibly choking it and risking smokeback and deadly CO in the living space. You will probably cool the flue gases below the condensation point and this will cause creosote deposits and raise the possibility of a chimney fire.

Your existing woodstove firebox is not designed to do what a batchbox does, so a lot of modification would be required. It might be possible to build a proper core inside of it but you'd have to be pretty fortunate if all the dimensions turned out to work.

My grandfather had an old Ashley in his basement, and a newer one upstairs.  They are simple but also ingenious,  I had a homemade replica for 8 years and loved it.  But I can see the wisdom dispensed here by two experienced men
Perhaps putting your energy into insulating could achieve the same warmth overall.

Hi Justin,
is that vent taking or bringing air?

If that vent is taking the air to other parts of the house maybe
building a quick J-tube rocket with a barrel and a simple mass (or another barrel as a bell)
would be good practice for the BBR build in 2026 and replace the old wood stove without too much cost and work.

Thanks all for your advice here.

Benjamin, to answer your question, the vent is in the supply duct of our heat pump/A/C. We open that grate above the wood stove when we're heating with wood. I like your idea of just building a j-tube rocket to use in the basement instead of the wood stove. Already sourced a couple barrels!

As I'm learning about BBRs etc, I'm realizing how specifically they are designed and that my stove could definitely not be reused as a firebox for a system like that. Maybe I can take it into the garage and add a barrel or brick bell for use in the shop.

Best of fortune to you in building a J-tube system... as long as you follow published directions, it will be fairly quick, easy and effective.

I think it would be about as easy and definitely more effective to just build a modest J-tube system in your garage than to try to retrofit a bell onto your wood stove with the exhaust cooling and creosote generation that would entail. If you do a garage system first, you will be prepared to quickly do another inside your house with full confidence.