New talk on Masonry Heaters

[qwee]

This is kind of a hard video to watch (flickering light), but I stuck it out. I learned a few new things about masonry heaters that I didn't know. The Russian types draw air better than the other types of masonry heaters - has something to do with the chamber design. So if your going to have a masonry heater built in a milder climate (NW/Seattle, lower mid/southernish states, etc...) the Russian design might be better. The heat from masonry heaters feels better, why? The heat radiates at roughly the same wavelength as the sun (I guess Tulikivi did a study).

They are built with a double walled firebox so that the inner wall can be replaced if it wears out (after many years). I thought they did this due to expansion. The Masonry Heater Association is doing everything they can to be tested by the Government. I guess they know they will perform well. The Austrians/Germans have mathmatically worked out a system that measures variables like passage sizes for optimal burns - so specs that their mass heaters must be built to (nothing like this in US because in US these heaters aren't regulated yet).

To view this content we will need your consent to set third party cookies.
For more detailed information, see our cookies page.

Accept third party cookies

 

[begreen]

There are several Russian fireplace installations in our area. It is a nice gentle heat.

 

[Hoytman]

I would love one of these in our home. Would be interesting to build these.

 

[qwee]

He says they are the best wood burning appliance ever created - but I thought pellet stoves got the best numbers. Pellet stoves have advantages due to air control and consistent fuel size. Maybe they have made some advancements in masonry heaters.

 

[logfarmer]

I would love one of these in our home. Would be interesting to build these.

I agree, it would be nice to have and I think fun to build!

 

[qwee]

I built a Finnish contraflow design. The hot gasses go straight up, the passage narrows, into a chamber (a bell), gasses swirl around in this bell, then go straight down the channels on the sides, all gasses meet up under the firebox, and then out the pipe and chimney.

I started with a bunch of firebrick. But another way to go would be to buy a kit for the core. The pieces are big. You just puzzle them together. This could be assembled by the homeowner or a mason. After this, the outer layer is laid up. This is the easy (time consuming part) and the homeowner could do this part.

He says he has built MHs on 4" slabs, with 6-8" being more common. I made a 20" hole with rebar because I was worried about supporting this thing. And to eliminate heat going into the slab, I poured about 2" thick perlite-concrete mixture at the base - a heat transfer stopper.

A new concept - using a carbide ceramic kiln shelf for bake oven with 2" layer of soapstone on the carbide shelf. It heats the oven more quickly, easily.

Firebrick comes in various levels of hardness. It generally depends on the metal content (alumina) in the firebrick. Low duty is like less than 30% metal, medium duty 30-50% metal, and super duty 50% or higher metal (I'm not sure of exact percentages). Usually low or medium duty bricks are used because they are cheaper. The lower duty bricks chip up/get damaged faster when used in the firebox.

I used some 95% metal content firebrick in the firebox and 80% (or so) in the rest of the core - they were cheap because someone got them at a government auction and resold them. Good idea? Maybe - they are really tough/dense. Maybe not - they are so stiff/hard that they may not like thermal shock (heating and cooling), and may micro fracture - we'll see.

I think these super brick were made to go in a kiln that runs 24/7. Probably to melt down old guns and such. Masons don't generally use these super duty bricks because they are more expensive (and not really necessary for burning firewood). Time will tell, but I think they are just overkill and will be fine.

 

[mellow]

If I ever build a new house a MH will be part of the plans(best way to do one), but I doubt that will ever happen anytime soon. I would love to have the cooktop, it would be great to know I am getting double use out of the heat. Now I want pizza.