Wood fire masonry heater? Anybody?

[Kingcreek]

Came across something very new to me.
https://tempcast.com/
Apparently a Scandinavian design made in Minnesota. I can’t find any weakness in their claims.
We are currently discussing selling our 4BR house and downsizing. We are spoiled, yes. Houses on the market all suck compared to the one we have. We could sell off a few acres with our current house and still have several very nice potential homesites on the remaining land.
We are looking to go from 2500sf main floor (plus a finished walk up attic with dormers) to something 2BR/2B around 1600-1700sf on 1 floor with a full finished basement. Super High efficiency low utility.
This type of fireplace appeals to me but still researching…

[Nick1911]

Not a new idea https://youtu.be/9y08yBdoFsI?t=1424

A large amount of thermal mass helps regulate temperature, but requires a lot of material, and therefore expense.

[Kingcreek]

I like the fact that the whole thing is DIY’able and the heat circulates through the hearth and sides, multiple clean outs and homeowner serviceable in all aspects. The bake oven is pretty slick also.
It’s coded and efficient enough that restrictions don’t usually apply.
I’m looking at ICF construction and all electric getting away from the almost $4k of propane I’ll use this year.

[MechAg94]

Would it also help to have an air duct passing across the rising heat?  Doesn't need to be much.  The last picture on the link looked like it might have something up high.

My parents have that on their fire place.  Those fans are a bit loud at times.  On the other hand, the fire place installation does include a lot of brick.  It doesn't extend upstairs like that video showed.

[Brad Johnson]

From a BTU recovery standpoint, I think a stove combined with a stovepipe heat reclaimer is more efficient. Not nearly as pretty as a big rock fireplace, and lacks the thermal mass to for longer-term temp stability, but better at radiating heat into the space around it.

Brad

[Kingcreek]

From a BTU recovery standpoint, I think a stove combined with a stovepipe heat reclaimer is more efficient. Not nearly as pretty as a big rock fireplace, and lacks the thermal mass to for longer-term temp stability, but better at radiating heat into the space around it.

Brad

Maybe could be added if the pipe is open like some of the pics? Then it would be both radiant and convection heat. There is already a lot of up and downdraft in the system to capture much of the heat. I kinda wonder just how hot the pipe gets. And the idea is that a 2 hour fire heats for 12 or more hours. They claim no creosote buildup because of the heat and efficiency.

[Hawkmoon]

Google "Russian heater"

[K Frame]

Not a new idea https://youtu.be/9y08yBdoFsI?t=1424

A large amount of thermal mass helps regulate temperature, but requires a lot of material, and therefore expense.

Loved that show.

I was going to mention the massive central stacks that you see in older homes.

In the early United States one of the general ways you could tell English-built houses from German is that the German houses (as well as houses built by others from Continental Northern Europe had a central chimney stack, where English construction generally had fireplaces and chimney stacks on the ends of the house.

This house was built in Pennsylvania by a Swiss settler in the 1730s...



England had more temperate winters, so they could get by with end wall fireplaces, like this Robert Adams-influenced design...

[HankB]

When a former colleague built his house, he included a central fireplace stack, and he made sure the masonry was exposed (not behind sheetrock) on all sides of the fireplace. He also had air ducts embedded in the masonry and had small, manually switched fans to push air through. Had a hidden duct to bring in outside air to support the combustion, too. Worked pretty well and once it was warmed up, it stayed warm for quite a while. But I don't know about heating the house for 12 hours with a 2 or 3 hour fire - it may not have been that good up in Minnesota. (The subject of creosote never came up.)

[Kingcreek]

https://youtu.be/rzKnu6gOI9I

[MechAg94]

When a former colleague built his house, he included a central fireplace stack, and he made sure the masonry was exposed (not behind sheetrock) on all sides of the fireplace. He also had air ducts embedded in the masonry and had small, manually switched fans to push air through. Had a hidden duct to bring in outside air to support the combustion, too. Worked pretty well and once it was warmed up, it stayed warm for quite a while. But I don't know about heating the house for 12 hours with a 2 or 3 hour fire - it may not have been that good up in Minnesota. (The subject of creosote never came up.)

Sounds nice.  I like the interior stone work as well. 

[Bogie]

One of the houses I grew up in had three stacks... Four main rooms on each of the first and second floors, along with a stack in the back for a very large wood stove. Each of the main rooms had its own fireplace - so nine in all (there was a fireplace on the 1st floor back stack too).
 
One on the first floor had been retrofitted for a propane burner, and we usually ran coal in the big stove.
 
The stacks on this wood-frame house were on the interior, and shared between rooms.

[Brad Johnson]

Mom and Dad built their dream house in 2006. Part of the build is a HUGE masonry and native stone fireplace. The fire box is double-wall, the interstitial space is meant for air flow - intakes at the bottom, exhaust at the top. Even without a fan, there is noticeable convection. A small fire will heat their 25x30 two-story living area well beyond comfortable even when outside temps are single-digit.

Their problem is the chimney. At almost 30 ft total height, it's so tall that gasses cool long before they exit the stack. Creosote buildup is a big problem.

Brad