Masonry Heater

[4seasons]

After seeing someone post something about a Russian stove in another thread I went on a web search to find out what they were talking about. Now I am very curious about these masonry heaters. They seem to go by many names like Russian oven, masonry stove, ceramic stove, tile stove, kachelofen, Finnish Stove, Swedish Stove etc.... and many designs but the same basic premise of using a hot fast fire to heat some kind of stone or masonry which then radiates heat for hours after the fire has gone out.

So I am left wondering why I have never seen one before. Apparently they have been around much longer than the wood stove and from most of what I have read they are more efficient. Beyond the 3 big drawbacks of size, weight, and cost, I am wondering why they don't seem to be more common.

Now I have several questions to anyone that has one or at least done more research than me.
1. If you actually use one, how do you like it, and what if any problems have you encountered?
2. Many of the designs have the smoke traveling down sometimes even lower than the firebox to exit out the chimney. How does this not create draft problems and build up creosote?
3. All the designs seem to have blind chambers and corners that cant be reached. Do you not get ash and creosote buildup in these areas? If so how do you go about cleaning it out?
4. If you have used both a wood stove and masonry heater in the past, how did they compare on ease of use, maintenance, and wood consumption?

 

[zogger]

Subscribing, I am interested as well from any hands on with anyone here.

I have to speculate, because the stove runs at jet fighter plane afterburner levels (or some such facsimile), it just slap burns everything burnable and any buildup is minimal, as in it might take multiple generations to have any sort of effect.

And even then, if you got some sort of chimney fire, it would be, oh well, self cleaning.

 

[mellow]

I saw my first ones working at the Wood Stove Challenge, tons of different ways to do it but in the end, it is all about a hot fire, many exhaust exit turns, and thermal heat retention.

Pretty much you blow up a bunch of BTU inside it and slowly release it to the outside world, kinda like fukushima.

As you mention, weight has a big part of why you don't see many, size also plays a big part, and you can't walk into your local stove shop and have it installed the next day.

Woodstock bought matt walkers stove at the challenge so we might be seeing a smaller scaled down version coming from them in the future.

It was cool seeing them work at the challenge, load them up and let it go, can't get any easier than that.

 

[Chris-PA]

I'd love to see a good diagram/drawing of one showing how it is constructed.

There are many ways to use a large thermal mass to store the heat from the stove, and masonry is a good material for it. I have a tremendous amount of stone surrounding my stove, and it does help a lot in storing/re-radiating/leveling the heat output.

 

[nk14zp]

I use a RMH and I still need to add more mass. I love it. There is no creosote because it is burned off in the wide open fire.

 

[mellow]

Here is some info on Dragon Heater's portable rocket heater, has a good diagram of how it works: https://store-lmpge.mybigcommerce.com/content/6Portable300.pdf

 

[Chris-PA]

Here is some info on Dragon Heater's portable rocket heater, has a good diagram of how it works: https://store-lmpge.mybigcommerce.com/content/6Portable300.pdf

That is interesting but I do not see a thermal mass, at least not as part of the stove in the diagram provided. So I think it is a somewhat different beast than the traditional masonry heater.

My hunch is that masonry heaters are mostly from areas that do not traditionally build structures from masonry, so it makes sense to build the thermal mass into the stove as a self contained unit. I believe the idea is simply just to burn hot and extract the most heat possible from the exhaust stream by making it run a long path, transferring heat from the smoke into the masonry through convection/conduction.

I personally prefer the idea of burning a secondary combustion stove and transferring the heat into masonry through radiation. But in the end any way you can burn without sending a lot of heat or unburned particles up the flue, while storing the heat for longer term release is effectively accomplishing the same thing.

I do think that the idea of thermal mass gets skipped over in many stove installations.

 

[mellow]

I do not see a thermal mass

The thermal mass is in the 55 gallon drum:

 

[mellow]

Good read on Bell vs Flue types of storage: http://blog.dragonheaters.com/wood-heat-storage-flues-vs-bells/

 

[mellow]

This is a video of matt walkers stove in action, I like his design as it reminds me of the old Jotuls:

 

[BrianK]

The thermal mass is in the 55 gallon drum:

In that design, the 55 gallon drum simply radiates heat into the room. It is not a thermal mass unless it is lined with fire brick. They don't usually line the first barrel with firebrick. The exhaust would then have to be run through a cob bench, a bell, a barrel lined with firebrick, or other thermal mass to store the heat.

 

[Chris-PA]

In that design, the 55 gallon drum simply radiates heat into the room. It is not a thermal mass unless it is lined with fire brick. They don't usually line the first barrel with firebrick. The exhaust would then have to be run through a cob bench, a bell, a barrel lined with firebrick, or other thermal mass to store the heat.

Agreed - there is no thermal mass shown in that brochure, and the drum is not enough volume to be a significant thermal mass anyway. Build a trombe wall on three sides and it could work well.

 

[Vermonster]

I believe the one I saw in use last month weighed 18,000 lbs. Very impressive. They also had a beautiful iron wood fired cooking stove next to it for really cold weather and for cooking/baking.

http://www.arboristsite.com/community/threads/russian-furnace.248497/

 

[Chris-PA]

I'm holding out for a Hypocaust.

 

[Motorsen]

Here is a page from a guy from Denmark who is highly respected and even have a page in english: http://www.stenovne.dk/englishpage4.html
Might also serve as a source of inspiration and entertainment reading.
Have a nice weekend.

Motorsen

 

[demc570]

cool idea,subscribed.....opcorn:

 

[Guswhit]

Here's one that I have been perusing. I like the look of the soapstone. Haven't done enough research yet on weather they are any good.
http://www.tulikivi.com/usa-can

 

[4seasons]

I'm holding out for a Hypocaust.

Ummmm, what is this?

 

[apn73]

http://www.mha-net.org/
This website is all about masonry heaters, it's a good read. I have no experience with them, but a coworker of mine swears by his.

 

[Vermonster]

Here's one that I have been perusing. I like the look of the soapstone. Haven't done enough research yet on weather they are any good.
http://www.tulikivi.com/usa-can

$$$$$s, but beautiful work from the old country.