Question About Alt. Heating.

Started by Virginia Gent, January 07, 2010, 12:37:09 AM

Previous topic - Next topic

0 Members and 1 Guest are viewing this topic.

Virginia Gent

So I've been torn between two types of building styles that I've discovered from this site: your average wood-frame construction and a style called HTM (High Thermal Mass) Construction.

My question is, is it possible to heat a home with only a wood-burning fireplace? I don't have the website on hand, but I know there are wood-burning stoves and fireplace inserts that are highly efficient at burning wood for long periods of time and heating large sq. ft. amounts. Is it possible to, as an example, have a fireplace with one of those inserts but find a way to alter it so that some of that extra heat is blown into duct work spread throughout the house? I know there are many other things to take into account, like a steady supply of firewood and so forth, but this is for the sake of brainstorming/gathering information.

So what y'all think? Any advice/info. for me?
"I would rather be exposed to the inconveniences attending too much liberty than to those attending too small a degree of it."
~Thomas Jefferson~

rwanders

I have seen many cast iron or heavy soapstone wood burners that include a separate chamber adjacent to the firebox which is heated and which also includes a blower to spread the heated air----some simply out a grille and some with a few ducts to direct the airflow in different directions. There are numerous styles, both inserts and free-standing sold. Heating capacity is simply dependent on size-----but don't forget that a large freestander will require a larger area around it to be comfortable for you to share that space with it. Will never forget a guy I knew in bush alaska who had a cast iron stove, really red hot----unfortunately, standing close to it, he lost his balance while drying off after a shower and------sat his bare butt down on that hot stove and fried it and a few attachments really good.
Rwanders lived in Southcentral Alaska since 1967
Now lives in St Augustine, Florida


MountainDon

How large a house?

We heated an 832 sq ft, single story home back home for some 8 years with a Vermont castings wood burning stove, the original Vigilant model. We had no issues at all with it. That was in Canada and we went through about 3 cords a winter. That stove was centrally located in a fairly open floor plan. The two bedrooms were cooler than the kitchen and living area, but that was fine. A larger two story home might be another matter. So. my answer is yes it can be done, with some "depends".

That home had a basement and that would be rather cold, but we did not use it for living space. It was laundry, workshop, darkroom and a play/recreation area. I heated/warmed the workshop or darkroom whenever I wanted with one or two electric heaters. When we might want to use the pay/recreation area we fired up the hydronic boiler (hot water heat). I had a set of valves that would only direct the heat to the basement when we needed it.
Just because something has been done and has not failed, doesn't mean it is good design.

Virginia Gent

I was thinking of building the 20'x34' 2-Story Universal Cottage. I know it's two story and that adds another dimension, however I was thinking of editing it some ...

http://www.countryplans.com/Downloads/study_pln.PDF

If you look at those plans, you'll see the space where the Entertainment/Fireplace would go alongside the stairs. I was thinking of extending it upwards into the above room too, so that instead of one fireplace, you would have two. Of course I would also be flipping the upstairs floor plan so that the master bedroom would be the one with the fireplace, and the two spares would be where the master would originally be. With it set up like that, I was thinking of having it set up into two separate sections: the downstairs fireplace with blower/duct work to heat the 1st floor, and the upstairs fireplace with blower/duct work to heat the 2nd floor.

Also note I'm well aware of the folly of leaving a burning fireplace/cast iron stove/etc alone and I, naturally, wouldn't lite a fire up there then go downstairs for an extended period of time, leaving it unattended. The idea is more like yours Don with the space heaters for general use upstairs and then close to "bed time" a fire would be made up there to heat the upstairs and be put out just before bed.

EDIT:
I found the website with the fireplace I mentioned earlier: http://www.quadrafire.com/Products/Wood_Burning/Wood_Model.asp?f=7100fp
As you can see it has the ability to heat upwards of 3,100 sq. ft. and the 2-Story Uni. is only, basement not included, 1308 sq. ft.
So in theory, just one fireplace should be able to heat the whole house with the proper fan/blower/duct work/etc correct?
"I would rather be exposed to the inconveniences attending too much liberty than to those attending too small a degree of it."
~Thomas Jefferson~

pagan

We heat solely with wood and in central Vermont that means leaving a fire going while nobody is at home. Right now as I sit and type this our stove is burning and it's 16 miles away. I was raised with a wood stove that was never left unattended. My father would tell me of the chimney fires they had when he was a boy and I even remember being at my grandmother's house when she had one. Today, however, stoves are far more efficient and clean burning. With a well insulated house you're only going to be burning three to four cords and not the fifteen to twenty like my grandmother. I insulated an old farmhouse and the owner told me they went through over thirty cords a year. We have 640 well insulated square feet and don't even burn two cords, and that's using an old Waterford Stanley wood cook stove for all of our cooking and heating. I originally was cleaning the flue twice a year but now only clean it once a year because there simply isn't enough creosote in it to justify climbing up on the roof that often.

Personally, Virginia Gent, I think it's a waste of money to have a second stove upstairs, unless you want it for romantic ambiance. If you insulate well it will easily overheat the second floor. We have only the Waterford Stanley downstairs and sometimes the second floor of our house gets too hot, even burning it as lightly as we do. Granted you're looking at building a much larger house, but I would recommend waiting on the upstairs stove until you see how well the one stove downstairs performs.


Don_P

Ditto from here on the no need upstairs, I can run us out of the upstairs with the little Jotul that's on the main floor. We have 100sf down and 500 up, the stove is in the L of the stairs. All steel studs covered in durock around the entire alcove all the way up, no wood basking in the radiant heat. Distributing the heat around the downstairs is the trick. I did set up the chimney chase as a return to the crawlspace intending to use it as a distribution plenum pulling air down along the pipe inside the chase and into the slabbed crawlspace to be distributed to floor registers. The thought of a fire getting loose in the chase and being fanned under the floor discouraged my hooking it up. Things to think about. I've about decided to rework it with a water jacket in the chimney chase and move water around rather than air.

A friend of ours has a Crossfire built in that does a very good job on their bermed ~2000sf.

pagan

A masonry heater would be another way to go if you want to avoid leaving a fire burning while you're gone.

MountainDon

I never worried about leaving the fire burning in the wood stove back home when we were away. Same thing withthe cabin we now have. Most often when we leave there is a fire still going. I may adjust the air inlet down, but never try to smother the fire or put it out. If the wood stove is installed properly and the chimney cleaning attended to I don't see that as any more dangerous than the natural gas fire in the furnace. Back home I did a mid winter cleaning, just to be sure the chimney was clean and safe.
Just because something has been done and has not failed, doesn't mean it is good design.

Virginia Gent

Thanks for all the replys! The 2nd fireplace upstairs, assuming the heating of the one downstairs was efficient, would be more of a romantic-ambiance, I've-always-wanted-a-fireplace-in-the-bedroom type thing  :P

I'm glad to hear that heating a house with a wood-burning stove/fireplace works and quite well by some of the stories here. Again, I thank you all for your advice and words of encouragement  ;D
"I would rather be exposed to the inconveniences attending too much liberty than to those attending too small a degree of it."
~Thomas Jefferson~


MountainDon

Hey Virginia gent, I must admit that a fireplace in a cozy bedroom does have a lot of romanticism going for it.   :) :)


Here in the SW a very popular form of personal fireplace is the Kiva fireplace.



http://www.kivafireplace.com/

They might not fit all decorating themes. 
Just because something has been done and has not failed, doesn't mean it is good design.

considerations

My former house in Oregon was a one story and had the smallest Quadrafire they made at the time.  It also had an electric forced air central heating system....however.  In the winter what I did was fire up the stove and then just turn on the fan part of the furnace system. It distributed that toasty warm air very nicely all through the house.   This was before. 

Now I'm heating the whole house with a wood stove and except for some brisk mornings, I'm comfortable. A "back up" vented propane furnace is in my future.  It just makes sense to me to have choices.  As an example, if I break an arm or something, the wood stove may become hard to maintain for a while.  Conversely if I run out of propane, the wood stove can cover the need.

Hope this helps you puzzle things out for your own needs.

paul wheaton

I have been making the same explorations!

There is a guy in missoula, montana that built a house where he claims that after a few years he didn't need to heat it at all because he had so much thermal mass.   I wrote an article trying to mash his ideas into a far cheaper oehler structure check out www.richsoil.com/wofati.jsp

Next up: a rocket mass heater.  A tiny fire gives you heat for days.  More heat stays inside.  I have now been to two of these workshops and am gonna build one of these in the next couple of weeks.  My notes so far www.richsoil.com/rocket-stove-mass-heater.jsp


RainDog

 
Fascinating. The kind of stuff that makes me want to call out to someone to come see. Thanks a lot.

Knee-jerk question here, but why couldn't an ordinary wood burning stove be vented through a large thermal mass in a similar fashion to the rocket heater? One would need some method of heating the final run of exhaust pipe in order to create the chimney effect, but it seems to me it would be a much more efficient use of heat, to contain at least some of it within a mass rather than just throwing such a large amount of it straight up through the chimney.

There's something very basic that I'm not catching about this, right?
NE OK

paul wheaton

A regular wood stove depends on heat in the chimney to move the smoke out.  So if you don't push some of the heat out of your house, the chimney thing doesn't work! 

Plus, if you did try it, a regular wood stove does not burn as completely as a rocket mass heater, so you will have creosote problems.



RainDog

 I suppose that's what I'm not understanding, as I was under the impression that heat in the final stack was exactly what was moving the exhaust through the mass in the rocket stove as well.

Havin' some kind of brain fart or something, I guess, but I'm just not grasping why a woodstove couldn't act as the firebox and combustion chamber, then vent out exactly as the rocket stove does. You heat the exhaust pipe, which starts the chimney effect, then the main fire's heat continues the effect. That the "pocket rocket" is essentially a wood burning stove, but without the thermal mass.

I know it's not rocket science. Like I said, brain fart or something.

Thanks!
NE OK

MountainDon

There have been a few rocket stove projects around here. A quick forum search has turned up...

http://countryplans.com/smf/index.php?topic=2350.0

http://countryplans.com/smf/index.php?topic=3468.0

http://countryplans.com/smf/index.php?topic=2410.0

http://countryplans.com/smf/index.php?topic=6163.msg81547#msg81547

A major difference in a rocket and a conventional wood burning stove is the size of the fuel. Rockets burn small stuff, more like kindling than logs. They burn it fast and hot and that helps keep the system clean.
Just because something has been done and has not failed, doesn't mean it is good design.

paul wheaton

Yes!  Fast and hot keeps it clean and safe!

And there is no smoke - there is "exhaust" which is usually about room temp.  So more heat stays in the house.

Pocket rockets don't keep all the heat inside.  Plus, they don't burn as completely.  They still depend on heat in the chimney to move the smoke out.

My understanding is that you heat your home with about five times less wood. 

And while the wood is usually smaller, I have seen a 6 inch RMH burn a stick with a diameter of about 5.5 inches.  And, while your coventional woodstove takes thicker chunks of wood, I've seen folks load a RMH with three foot long sticks. 


Don_P

I've been looking at wood gassification units. A engine can be run off the woodgas, it is generating power while running. The water jacket is circulated into a building for heat and the exhaust heat is used to dry the next batch.