The Rumford Mass Fireplace

How would that differ from a masonry heater aka Russian fireplace?

The Rumford design as I understand it is all about two things; maximizing radiant heating via the shallow, angled aides, and minimizing losses of heated room air, by means of a streamloned chimney theoat to reduce turbulence.

If you kept these aspects, this would make it quite different from a Russian fireplace/masonry heater, since those are generally built to absorb as much heat as possible from short, hot fires, via ducting, ie turbulence... then radiate this out from the mass over time. Pretty near polar opposites...

I don't think changing either aspect of a Rumford in isolation would work well, the features strike me as interdependent.

Adding substantial mass to an otherwise unaltered Rumford design doesn't seem terribly problematic, but I can't see it performing as well as a purpose built mass-heater. However, I like the idea of building a Rumford into the same mass as a masonry heater/RMH...

"However, I like the idea of building a Rumford into the same mass as a masonry heater"

That was my thought. I just wonder if it would be worth the effort. I cant find any info on it.

I think that would work fine. Just locate the RMH appropriately, and add the Rumford to the side of the mass where it will be comfortable to use. There would end up being some extra thickness in parts of the mass wall, but that would be a minor issue. You would of course need separate chimneys.

Its been a while since I researched this but it is based on pressure differentials in the chamber, pressure and temp differentials at the bottom and top. The top high flow, low pressure and temp. Bottom inverse, that creates a tall burn, very clean, very efficient! Some smart guy that knew how carburetors/venturi worked probably invented it. The underlying principle is Bernoulli's. Surround it by mass would be nothing new. Since the heat is tall and fast at top there is probably a temp drop it would still make sense to extend the mass more vertically than horizontally. There are a number of inserts that can be set in mass.

IIRC, there is back sealed flapper to exterior air or you can design intake and exhaust. To get the design to work properly one must follow the engineering. The key is the size and shape of the convergant vertical exhaust up the flu. That is why an insert might be a better way to go since it s/b tested.

Feel free to correct me, again it's been a while.

I'm looking for a wood burning stove unit if anyone seen one. My freezing temp HVAC loads are so low I'd overheat the place with mass

David Hogan : Here is a link to the history of the man and the fireplace below :

https://en.wikipedia.org/wiki/Benjamin_Thompson

Note in (figure#6) the rebuild of the old ''Ox Cooker'' style into a Rumsford ! A further search with '' Rumsford fireplaces pictures'' or " Rumsford fireplaces images ''

should show you that the amount of mass that you can add is nearly unlimited! I would however build it totally internally or if necessary to build against an outside wall

add an insulating box around that structure !

Some where there is a picture of a Rocket Mass Heater that had a small Rumsford Fireplace included - This would generally require that only one got used at a time or

that there were two chimneys ! - If i can locate that picture I will post it here. For the Good of the Crafts ! Big AL