thomas rubino

Hi Matt
All four walls, floor to ceiling, and the ceiling itself are measured.
The core and core door are not measured.

Hi Matt;
The exhaust box is not counted.
It is very small, located at floor level with an opening of apx 8" x 12".
The walls and roof all count inside the box, unless insulated.
The height of the core will change, where the highest heat is concentrated.
It does not affect the output of the Batchbox.
Peter calculated the correct ISA for each Batchbox size's output.

We have two.
A poor man one, for Liz in her art studio, this gets daily heavy use.
And my 1940's WW2 surplus vice, it gets used quite often itself.

Hi Matt;
I like your design with the step out for the exhaust; both my Shorty core build and the Studio Dragon build use one to bring the exhaust stack into proper position.
Your core heat will rise before sinking; you should not have any issues.
A straight stack is always preferable. Be sure to position the pipes so that all moisture stays inside, and I suggest using metal duct tape at each pipe connection.
Shorty core is easy to build, except for the three slabs needing to be poured.
I believe Peter, reduced by ISA 10% from the first-generation Batchbox design.
It does require a bypass pipe to ease cold starts, but with a stepout for the chimney, installing a bypass is pretty easy.

Build a small brick box "manifold" and add a cleanout door, either a stove pipe cap or a cast iron door.

And a big yes on adding the plumber's tape to support it.

Yes, that is the correct primer and glue.  Make sure there is enough, and the glue has not solidified.
A hacksaw will work; a side grinder with a skinny wheel would be faster.
Wear gloves, and if you have one, use a face shield.
If your original pipe has no play, you may find it hard to make all the connections.
When priming and gluing PVC pipe, you need square cuts and complete insertion of each piece to get a water-tite bond.
If you have trouble, they do sell a slip-on repair piece called a compression fitting, no glue needed.

Hi Marta;
Yes, this post is intended as satire.
It is all true that I have twice bought #10 of blank newsprint.
I like it a lot, and now use it exclusively, rather than dealing with printed paper.
The real point here was how little wood you burn with a mass heater.
Paper is cheaper than cords of wood... and USPS drops it off at my door.

Oh my, I have piles of dry bark duff in the wood sheds.
Very little, paper birch nearby, as that is an excellent fire starter, and I would use it. I love the smell!
Pine cones work, but not really well until dry.
I like using newspaper, fast and easy, and it works every time.
Oh, and do I use a propane torch on the paper and kindling in the shop and studio, but just to get them going faster.

I intended this post as a satire.
My point here was not really the cost of the newspaper, as much as how little your RMH is burning.
$50 for paper versus the cost of multiple cords of wood.

It is a win-win when you start heating with bricks instead of wood!

By building Shorty in our home, and completely rebuilding the Studio Dragon, an unknown cost has reared its ugly head!
For years, during any trip to the "city" we picked up several copies of a local "Bargain News" for sale paper.
All sorts of good stuff you might need. Each copy was read and then placed in the burn pile. Month after month, they kept adding up.
By winter, you had a good-sized pile at each stove, and we never ran short of fire starter.

Until we built Shorty, our house had a traditional-style wood burner, with a fire lit in the fall and not allowed to go out until spring. Sure, we had to relight a few times in the spring and fall, but for the most part, there was always coals to get it going.
Prior to building the new Studio Dragon this fall, my old original RMH was lit once a day, and continued burning until nightfall.
With the new high-mass double-wall Dragon, she gets lit once in the morning and then allowed to go out. Later, if it's cold, we might light a midday fire, let it go out, and then have an evening fire before we shut the intakes down for the night.
Now that I am retired, "haha," the shop stove is only lit once and kept burning until I quit for the day, which gave me a "stash" of burnable fire starter to move to the house and studio.
By mid-winter, paper was getting scarce. Sure, we have junk mail and cardboard, which are crappy fire starters, but burn fine when tossed onto a bed of coals.
If we lived near a city, local newspapers would be freely available once they were out of date... thank goodness we DO NOT live someplace like that!
As of mid-winter, we are now purchasing blank newsprint 10#s at a time for $27.20 !!!
By spring, I will have spent over $50 on paper!
Who knew? Nobody told me that these RMHs had such an appetite!
https://www.amazon.com/dp/B081VXLC2R/?coliid=I2XGANVJDHQAIG&colid=1C1TN95U35AY6&ref_=list_c_wl_lv_ov_lig_dp_it

Be sure to add this hidden cost when calculating the financial feasibility of building your RMH.
No RMH, paper is free!!!
Firewood consumption is at its maximum.
With RMH, newspaper costs skyrocket to over FIFTY DOLLARS!!!
Firewood consumption is minimal...
Your Choice...