Masonry Heater vs Wood stove

[begreen]

MH (and fireplaces) are covered in the main Hearth forum. Always have been.

 

[DevilsBrew]

MH's aren't exactly stoves or fireplaces. Just my opinion but without a special area for these types of heaters, would think The Green Room might be a good place .

Thanks for the idea, Dave. I will try dropping my experimental stuff in there since most of it is ideas and concepts about design and not actually finished MHs.

 

[pen]

The description of The Green Room is pretty clear:

This area is for discussion and links of renewable energy and conservation NOT related to stoves - such as solar, wind and water power as well as conservation, ethanol and other evolving technologies. Long debates may be moved into the Ash Can....we would like this area to be a resource!

As BG said this (The Hearth Room) is the right room for discussing Masonry Heaters. If enough interest were to arise then perhaps a dedicated room would be appropriate. This is what happened years ago when the pellet room was created.

pen

 

[firefighterjake]

How do you sweep a MH? I have to think, even with the intense fire, it needs to be done every once in awhile?

The one I saw in use had access "ports" where you could run a rodded brush through to clean it out periodically . . . but that said . . . much like our EPA woodstoves . . . if you have truly seasoned wood and run the masonry heater as it should there is only a little build up of creosote or fly ash.

 

[Ehouse]

There are many intermediate forms, many free standing, incorporating different amts. and types of thermal mass (soapstone, tile, plaster) many are European but there are some domestic examples (Vermont Bun Baker). Google kachel oven for some pics. I'd swear some are using Hearthstone castings! Advantages include spreading out the burn, (although slower start up), touch no burn, and close clearances to combustables.

 

[downeast]

True Viking here boys and girls and Webbie: we really, really didn't do all that much R & P. Just a bad rap for some wild and crazy guys looking for a good time.....in boats.

Back to reality--the OP has fallen in love with an idea. He's got some points, but let me bring you to our Masonry Stove/ Russian Fireplace decision over a decade ago when building here in a winter climate.

Much has been said before about efficiency ( never real world determined ), cost ( a lot more than any stand-alone wood stove ), space ( a home needs to be built AROUND a MH/RF ),
sizing ( byQ can't simply run out and get stones, bricks, and mortar without some PLAN for the structure ), support ( substantial foundation for the weight ), and finally the ART of building one.
Add to those facts, the experience with the many high quality wood stoves we had over the years, the cost comparison ( two high end, at the time, wood stoves new were 1/4 of the NET cost of even a self-built
Masonry Stove/Russian Fireplace, and the extra expense to INCREASE the size of our home to accommodate the MH/RF.

Told before here -- we heat 2000 ft² with NO central furnace backup, 24/7, 2 wood stoves, harvest 6-8 cords from our woodlot each year, flush/running water/showers, and we don't enjoy discomfort.

Some advice byQ: do due diligence. "Do due diligence" ( rhymes, huh ? ). Get out and see actual MH/RF units in use in winter. We did. They do the job well and effectively with caveats. So do all the wood stoves we use.

And please: get off this "Euro is better" schtick. They have some serious problems ; one of which is a lack of easily gotten firewood. We'll save the higher end political and economic talking points for later.

 

[byQ]

I didn't know masonry heaters were exempt by the EPA. I guess they figure if it's a masonry heater it will burn effectively due to it's high heat in the firebox. If I remember right, up in Fairbanks, Alaska, wood stoves could only be used at certain times but masonry heaters could always be used. It might just be pre-EPA stoves, though.

This is an air stagnant environment in winter. Looks like the regulators are in favor of masonry heaters over wood stoves. I think the college in Fairbanks is trying to educate the public.
Notice the big common river rocks used in this large masonry heater.


They say 98% combustion efficiency and 80% efficient. I'm guessing this means that since wood always has some water in it (15-20%) you will always lose some efficiency.

I think this helps clarify combustion efficiency "......The overall efficiency of a wood heater, however it is measured, is the product of the combustion efficiency (sometimes called chemical efficiency) and the heat transfer efficiency. If all the carbon, hydrogen, and oxygen contained in the wood fuel are converted to carbon dioxide and water by combustion, then the combustion efficiency is 100%. This of course does not happen.........Combustion efficiencies are, however, high compared to heat transfer efficiencies and they are generally 90% or greater (referring to EPA wood stoves).

Heat transfer efficiencies relate to the amount of the heat energy produced by the combustion process that warms the inside of the house versus what is lost out the stack. Heat transfer in the home occurs in three fashions - radiative, conductive, and convective transfer. ......."

 

[byQ]

This is pretty interesting. I've never seen anything like this. He says it's a masonry heater but I see a barrel wood stove and a mass of bricks. So he has run his wood stove exhaust pipes into the thermal mass and than back into the exhaust. It's a wood stove/masonry heater hybrid?

One advantage a wood stove has over a masonry heater is that it can heat things up quickly where as a MH initially takes about 10 hours to start warming things up. He is trying to have the best of both worlds - convection and radiant heat.

 

[begreen]

Often a wood heater is exempted if it is the sole source of heat. This is not based on efficiency.

 

[byQ]

Often a wood heater is exempted if it is the sole source of heat. This is not based on efficiency.

I know it is illegal to pass someone on the side of the road in Alaska during the winter if car broke down. So, what you say makes sense - how could a homeowner be told to stop burning in minus degree temps if all they had was a pre-EPA wood stove?

 

[osagebow]

I am going to guess you have never actually been to Europe? I lived there for a decade. Married one and brought her home.

You want to know what Germans think and say about America? I can tell you first hand. Her whole family wants to come here on vacation, they don't want us to go there. Her parents come over, rent a car and just freeking drive for days. They have seen more of this country than I have! Yep most of them live in small, multi family/generation homes. Where my wife is from, Erlangen Germany, in Bavaria, bare ground, if for sale, would be about 4 million euros an acre, and would cost another million to get/have anything built on it(permits and such). That's why. Her family comes to visit, and just marvels at the 10 acres of woods, huge house and beautiful open views of our little valley, the fact that the forestmeister doesn't tell me IF I CAN, or WHICH deer to shoot, or tree to cut. etc etc etc.

Well said, DD! I have heard this from my exchange students. "You have 11 acres?...on a Teacher's and nurse's salary?" I do respect many European ideas and ideals on food, fitness and frugality. Have a Franzi in the fridge, gonna pour it and proclaim "Ich bin ein forestmeister!"
sorry if I screwed that translation up.

 

[Seasoned Oak]

I found these, too. He says a masonry heater only uses 1/5 the amount of wood as a steel wood stove - wow, this is hard to believe.
"....Inside, masonry stoves (heaters) burn hotter than metal wood stoves, and masonry heaters winding maze of flue (baffles) warms the surrounding masonry, which than emits heat for 18 to 24 hours. The temperature can reach 2000 F inside some masonry heaters (vs 700 F inside a metal wood stove), .. A metal stove gives out its heat rapidly, thus never allowing the inside combustion temperatures to achieve the 1100 F plus needed to ignite all the gases...."
"...Because the stored heat radiates slowly from the masonry, it is only necessary to light a fire once a day in most cases. In really cold conditions, you might need to light two fires a day. Metal wood stoves must be tended to continually, and they fluctuate from peak high temperatures, to no heat, when the fire goes out. If you tamp down the flue on a metal wood stove you increase the emissions of pollutants as the combustion of the wood is incomplete.A masonry heater will use 1/5 (or much) less wood, then a home heated with a metal wood stove. All well designed masonry heaters easily outperform the highest rated
EPA certified metal wood stoves. And like a wood stove, a masonry heater can exhaust through a metal flue pipe....."

ID have to call BS on that 1/5 as much wood claim. There are only so many BTUs in a given piece of wood. No matter what kind of stove its burning in.
ALso my wood stove internal temp is WAY WAY over 700 deg. The outside is 700 degrees ,the inside is 1500+ in the ceramic reburn chamber.
Also i only do one fire a day on many winter days and very cold days its 2 loads of wood. So my wood stove match's the MH on all those points.

 

[DevilsBrew]

ID have to call BS on that 1/5 as much wood claim.

I just watched a workshop where the individuals had nothing at all positive to say about metal stoves. The financial and political motivations of individuals need to be taken into context when grandiose claims of a product's efficiency are declared.

 

[Hogwildz]

I smell someone that doesn't seem to have any wood burning appliance, and thumbs through the internet and now thinks they are a complete encyclopedia of information regarding Europe, USA & all wood burning appliances. You ain't building no MH for $2k. Don't care how you want to explain it, it ain't happening. I think someone missed a few doses of meds.

 

[pen]

This thread has more than run its course.

closed.

pen