Masonry Heater Build

[lumbering on]

Here is my subscription to the thread. I find this very interesting.

I wish you the best of luck and look forward to the finished product and your review after the1st yr.

Ok, I'm in too. You've been so enthusiastic about the masonry heaters, I'd like to see this through.

 

[Todd]

Very cool project you have going there. If I were building a new home I'd also like to build it around a masonry heater. Good luck, keep us posted.

 

[byQ]

In the morning, I'm ready to start digging out the hole for the masonry heater footing - 8' x 8' x 1' deep with #4 rebar 12" on center. I've only got to go down 4" because I will be building up with sand and insulation for the rest of the house slab. I'm going with 3" rigid board insulation on bottom and sides of the hole. The rigid board is 8' x 2' x 1.5" thick.


My firewood collection is starting to expand. I've started cutting smaller (12"-16") and thinner (3"-5") for the masonry heater firebox. Lodgepole pine front pile to the right, elm and fir front pile to the left, and I don't remember what's in that back pile (mixture probably).

 

[Jags]

Again, cant the same heat storage be achieved by building a cement or stone structure around a regular EPA stove. Im tempted to try this as my stove sits on a concrete foundation on the basement floor.

Randy - the down side of doing this is potential harm to the stove. A free standing stove is designed to get rid of the heat it produces. If you box it in, the slow absorption rate of the surrounding stone/brick/etc. could easily over heat a stove.

Consider me subscribed to this thread. Very interdasted.

 

[Seasoned Oak]

ID still like to come up with some solution to the stove overheating the room its in to the point where its unbearable,possibly a solution where water or stone or sand is involved to store some of that heat. Right now i move very large volumes of air past the stove and still i can get temps in the 90s in there.

 

[byQ]

ID still like to come up with some solution to the stove overheating the room its in to the point where its unbearable,possibly a solution where water or stone or sand is involved to store some of that heat. Right now i move very large volumes of air past the stove and still i can get temps in the 90s in there.

That is a good question I have wondered about. Let's say you have 2 exactly the same houses except one has a concrete slab floor and the other has a wood floor on I-beams. Let's put 2 of the same wood stoves in each. In the wood floored house we put a lot of light objects and wood objects. In the other house we put a lot of thermal mass objects - like stone and bricks. Does the house with more thermal mass heat alot slower and thus cool down a lot slower?

 

[rideau]

Can't you put less wood in the stove and thus produce less heat?

 

[byQ]

Well I've got the insulation in place for the masonry heater footing and the two "hot rooms" I'm building. What's the world coming to - it actually rained a little here in the desert and the insulation got wet - so I'll let it dry out for a while.

Hot rooms,

Hmmm... the sun


6 or 7 hot water solar panels,


And a slab floor. I should put that PEX tubing in the slab (hydronic heating) and run hot water generated from the H2O solar panels through the slab for almost free heat. The tubing only costs about $300....hmmmmm.

 

[DevilsBrew]

ID still like to come up with some solution to the stove overheating the room its in to the point where its unbearable,possibly a solution where water or stone or sand is involved to store some of that heat. Right now i move very large volumes of air past the stove and still i can get temps in the 90s in there.

That is a good question I have wondered about. Let's say you have 2 exactly the same houses except one has a concrete slab floor and the other has a wood floor on I-beams. Let's put 2 of the same wood stoves in each. In the wood floored house we put a lot of light objects and wood objects. In the other house we put a lot of thermal mass objects - like stone and bricks. Does the house with more thermal mass heat alot slower and thus cool down a lot slower?

Wait...isn't that what some do with soapstone? Or am I totally lost?

 

[begreen]

To a certain point. But if the stove is seriously oversized for the area heated even soapstone stoves are not a panacea.

 

[DevilsBrew]

Q, how many people do you have helping you?

 

[Seasoned Oak]

Can't you put less wood in the stove and thus produce less heat?

To some extent.But small fires dont last long and are not smoke free as they do not let the stove go into afterburn mode where the smoke burns and also produces heat.. But if i want a 10-15 hour efficient burn i must fill the stove ,then turn down the air all the way to the lowest setting,even at this low setting the stove will produce enough heat to keep the stove room temps around 90 and the adjoining finished basement will be about 84-85 TH estove is in an unfinished part of the basement. It does take this much heat to warm the entire 3 story 3000 SF house. With the third floor just around 70. But it takes a lot of air movement to distribute it up 3 stories. IF i could store some of this excess heat somehow to even out these high room temps.

 

[byQ]

Q, how many people do you have helping you?


I'm doing the work myself, although i hired a contractor for the footing. I would like to finish leveling the slab with dirt and sand, and then putting rigid board insulation and wire mesh on. Next, I could start on the walls. But I have to get the plumbing done first. And I need to run 300' of a 36" deep poly pipe from the well to the house and around in an orchard. Plumbing - oh boy. I think my building efforts are going to slow down.

 

[DevilsBrew]

Impressive

 

[Seasoned Oak]

And I need to run 300' of a 36" deep poly pipe from the well to the house and around in an orchard. Plumbing - oh boy. I think my building efforts are going to slow down.

2 ? WHat is a hot room and what is the purpose of the 300' of poly. Sounds like a geo-thermal system.

 

[Nick Mystic]

Webby 3650,
I missed your post earlier when you said, "Just think how much heat is being pumped up and out through all that brick to the outside!" in response to my set up with the huge brick chimney and fireplace. The entire structure is centered inside the house and only the top five feet of so of chimney is outside. I have a stop off plate inside the fireplace opening and the top of the flue for the main stove is also insulated and sealed at the top. So, I don't think there is much heat at all being lost to the outdoors. When I installed my SS flue liner I filled the clay tile flue with fiberglass insulation at the top of the chimney down as far as the roof level.

 

[Nick Mystic]

byQ,
I'm not too familiar with pouring concrete. Did you say you are putting 3" of foam insulation under the slabs for the foundation of the masonry heater and hot rooms? Does that type of insulation remain stable with all that weight on it? I know it's called rigid foam, but can it actually support all those tons of weight? Is that standard for foundation work?

 

[byQ]

WHat is a hot room and what is the purpose of the 300' of poly. Sounds like a geo-thermal system.


What I'm calling a hot room is just a passive solar heat collection room. When building a house if one of the long sides is positioned so that it is facing south, and a lot of windows are put on this south side, the sun's rays will stream through the windows and heat things up. I'm manipulating this concept a bit more. The two rooms have thermal mass walls of cinder blocks. The sun's radiant stream passes through the windows and into the 4" thick cinder block walls. The walls build up heat and start passing it into the rest of the house. The walls also block the sun's strong glare.

Different colors are like doors for the sun's radiant heat. White is a color that only has an occasional door for radiant heat - so most of the heat isn't invited into the thermal mass. Black on the other hand is covered in doors for the radiant heat - so the radiant heat streams into the thermal mass and starts to heat it up. So I'll be going with black.

These rooms will each have a small entrance door. And I will put vents high and low so air can circulate. The winter sun because it is lower in the sky is invited to send its radiant streams into the room (when you want heat). The summer sun because it is higher in the sky is denied access to the rooms (when you don't want heat). This is done by roof overhangs. I don't know how much heat this will provide but it is free. Thermal shutters could be put on the inside of these south facing windows. So, they are opened in the morning, they let the winter sun in, and then as the sun is setting the thermal shutters are closed to hold in the gathered heat.

In a country setting, the poly pipe is just the buried hose that runs from the well to the house.

 

[byQ]

I'm not too familiar with pouring concrete. Did you say you are putting 3" of foam insulation under the slabs for the foundation of the masonry heater and hot rooms? Does that type of insulation remain stable with all that weight on it? I know it's called rigid foam, but can it actually support all those tons of weight? Is that standard for foundation work?

I was surprised, too. But this is common practice. One would think the heavy weight would cause problems but I guess because it is distributed it works. I saw where in a super energy free house they had 12" of rigid board under the slab - rigid board must be strong in a compression sense.

 

[rideau]

I put rigid board under my basement slab in mid 1970's. It ha worked great.

My sister bought a 1950s home in Ottawa in the early 70's. She build out the back of the home, to the south. In the kitchen area she built a wall that had pella windows installed on an angle - it was about 60 degrees, and had slats in between the two layers of glass in the windows. Those windows heated the entire house during the day in the winter in Zone 4. In the summer the angle of the sun was different and the area did not overheat. The slat blinds between the two panes were closed nights in the winter. The National Research council wrote up the build when they realized how effective it was. I have many times since wondered why more people don't do this. VERY simple and quite cost effective. You might look into it.

 

[Seasoned Oak]

ByQ
Im familiar wiith the sun room concept as i enclosed a south facing porch and made a sun room out of it and it lower my oil use (I had oil heat at the time) by about a tank(250 Gal) a year or about 20-25%. Sun room gets up to 100 even in winter if i dont open the house door and let the heat circulate into the house. Summer sun is overhead so it does not over heat.

 

[WoodPorn]

I have an acquaintance that builds these (or versions there of) professionally, he calls them russian stoves. They are made of 100% Soapstone and beautiful to look at.
Good luck with this build, and keep us posted.

 

[Tedinski]

Hello byQ!

How is your building project progressing? I've always been fascinated by masonry heaters.
SOME day I'll be building. I'd like to include a masonry heater as a central feature.

 

[DevilsBrew]

An update would be nice.

 

[Tedinski]

An update would be nice.

Hello DevilsBrew! It'd be great to hear your experiences with rocket stoves & such. Perhaps in a new thread? I'm very interested.

I'm in NW PA too! Fortunately, just a little south of the real snow belt.