Finnish Masonary Heater

[Onoff]

I came across details of this masonary heater in Finland that gets built into the core of the house. Comes in kit form, special stone. The heat seems to take a convoluted path to warm the big stone mass. Might interest @scottishjohn. Wonder if you could make one from granite, that'd be cool (no pun intended). A couple of pictures taken from the link:

 

 

 

 

 

There's a whole load on the history of them the guy has put up on the link below:

 

https://www.mig-welding.co.uk/forum/threads/a-look-at-my-masonry-heater.117942/#post-1973086