The Year of Mud: Cob and natural building » winter

Information Wanted About Cob Houses in Cold Climates

ziggy — Sat, 27 Feb 2010 23:30:58 +0000

This is a call for information from folks living in cob houses in cold climates – by cold, let’s say places that frequently have below freezing temperatures in the wintertime. If you live in a cob house in an area with cold and/or extended winters, can you describe the construction of your home and your heating system?

How thick are your walls? Do you have any insulation (in the roof, stemwall, floor, etc.?) What is the square footage of your space?

How are you heating your house? How often do you run your stove? Is the home occupied full-time during winter days?

Finally, can you provide average indoor/outdoor temperatures? How comfortable does your cob house stay?

I will followup with some insight into winter conditions in my cob house in the near future.

Tiny Wood Stoves For Small Houses: My Choices

ziggy — Thu, 25 Feb 2010 19:40:18 +0000

I’ve been researching small, efficient wood stoves that could replace the rocket stove in my house. Most home wood stove manufacturers’ smallest models heat 800-1000 square feet at a minimum, which is overkill for my less than 200 round foot home. However, the house will probably benefit from the extra oopmh with all of that (cold, cold) thermal mass and lack of insulation. Here are the two top contenders that I have been researching.

Jøtul F 602 CB

From Jøtul’s website come these stats:

Maximum heat output: 28,000 BTU/hr
Heating capacity: Up to 800 sq.ft
Max log length: Up to 16″
Over 75% efficient
Burn time: Up to 5 hours
Finish options: Matte Black Paint
Flue outlet: Top, and rear
Flue size: 6″ (w/standard adapter)
Weight: 160 lbs.
Accessories: Fire screen, Rear heatshield
Alcove approved for both the US and Canada
Fully functional cookplate
5 year limited warranty

This model is appealing because I can get it locally for $850, which isn’t a horrible deal considering they retail for about $1000. There are about five homes with this stove at Dancing Rabbit, and everyone who has used it has good things to say, which is comforting, too. It takes 16″ logs, which is also a nice feature (but in reality, it would probably take 14″ logs more easily.) However, I’m not that jazzed about the dimensions of the stove – it’s a little long, a bit too rectangular for where April and I hope to install it. I also don’t think the viewing glass is that great, either. Also important to note: I think the “over 75% efficient” is quite exaggerated.

This list of EPA certified wood stoves (warning: PDF) ranks the Jotul 602 as 63% efficient. (In fact, none of the stoves that I’ve found that say they are 75% efficient rank as such in this document.)

Morsø 1410

From Morso’s website:

Maximum Heat (BTU/hr): 30,000
Heat Output Range – lab. test (BTU/hr): 9,5862-22,018
Test Fuel Load: 5.15 lbs
Particulate Emissions: 3.3 grm/hr
Log Size: 12″
Max. Area Heated: 1000 ft²
Firebox Dimensions: 12¼”W x 10¾”D
Firebox volume/capacity: 0.736 ft³
Gross Weight: 215 lbs

This thing is tiny. On an aesthetic level, I like the Morso 1410 much more than the Jotul. It’s got a nicer viewing window and a great squirrel relief on either side of the stove. More importantly, it’s more of a square shape and not as deep as the Jotul, so it should fit better where we want to install a stove. I don’t think there is much of an efficiency difference compared to the Jotul. One drawback is the short maximum log length: only 12″ (and probably more like 10-11″)! That means more cutting. And since we do all of our cutting by hand (with a bow saw, hatchet, and maul), that’s more labor. (Which I’m not totally opposed to, but it is a significantly more work to cut small wood.) It also has an ash pan, which the Jotul does not. Drawback? The price I was quoted is $1000… sheesh! There’s got to be a way to get this thing for cheaper.

Check out this website for a review of the Morso 1410.

Since both stoves seem to be about as capable, efficient, and small as each other, it seems to be a choice we’ll make based on aesthetics. I’m leaning towards the Morso 1410 because of that.

The Tiny Temporary Wood Stove

ziggy — Wed, 24 Feb 2010 00:07:32 +0000

Here are a couple of photos of the tiny, super ragamuffin wood stove April and I are using right now. It’s manufactured by the Buckeye Incubator Co. Our setup is extremely tacked together, as you can see — the stovepipe runs out the top half of a double hung window. We didn’t exactly have enough stovepipe, so we straightened out some elbows to make a short straight run for inside the house. Outside, the stack rises a few feet above the eaves and is wired to the rafters to prevent it from shaking in the wind.

We used two perfectly sized sheets of metal (thanks Bob) and cut holes in the middle to seal up the window. Aluminum tape covers the edges and keeps air from sneaking in.

With this little thing, we can get the whole house decently cozy in about thirty minutes.

I’ll be happy to have a better quality stove in the house!

The Cone of Silence: Keep Warm in Winter With No Energy Costs!

ziggy — Thu, 04 Feb 2010 21:20:50 +0000

In our journey back home to Dancing Rabbit, April and I brainstormed ideas of how we could better button up the house for winter. At the time, the house was in the 30s, the rocket stove was clearly not going to keep us warm, and we didn’t have plans in place for a temporary stove yet. We expected to be cold. But we wanted to do what we could to make things more comfortable.

We came up with the idea of creating a sort of structure, almost like a tent, that would trap our body heat as we lay in bed. We recalled the four poster beds of old, which were beds with four vertical posts and curtains that lowered around the bed to keep drafts out and the sleeper warm.

Our version was something simpler, that didn’t require four posts. April drew up a little sketch of a hoop supporting blankets that would drape over the bed, forming a sort of warm cone.

April’s friend dubbed our warm body heat tent the Cone of Silence. (I didn’t realize it was a Get Smart reference at the time, but the name has stuck!)

The very next day, we found a mosquito net with hoop at a thift store for $2. (What luck!) We took off the net and used the hoop to support a couple of blankets (one 100% wool army blanket [another $4 thrift store score], and one quilt), which were safety pinned together. We tied the hoop to rope and strung it from a hook over the bed, above the pillows, where our heads would be exposed.

It looked pretty silly, but the results were amazing! We climbed inside. While the temperature inside the house was 38°, the temperature inside of the Cone of Silence had risen to nearly 60° from our combined trapped body heat! That’s a 20 degree difference!

The Cone of Silence is a little tight for two to sleep in, but the warmth makes it totally worth it. It doesn’t extend over our legs, but it does shelter our heads and shoulders, which would otherwise be exposed to the cold air of the house.

If you live in a terribly cold house and have no way to generate heat, use your own body and capture the heat you produce while you sleep! The Cone of Silence makes sleeping in a cold house much more comfortable. All you need is a hoop and two or three blankets. (I bet you could even use an old bike rim as a hoop.)

I proclaim the rocket stove “not working”

ziggy — Thu, 04 Feb 2010 03:02:51 +0000

I have officially proclaimed the rocket stove “not working”. The stove simply does not draw on days without the right wind direction/intensity. It is unreliable. Even when the wind is right, the stove takes too long to heat up (even the barrel itself!) At times, it smokes into the house, which is added frustration.

Something is not right, unfortunately. The stove just does not keep the house warm. When April was home alone in December, she struggled to keep the indoor temperature in the 40s! That is not really livable.

When we got back in January, the temperature inside was in the upper 30s. The house temperature dropped below freezing on a few occasions while we were away. (All of the canned goods had to be moved out.)

Within that first week back, we decided to move a temporary woodstove into the house. It’s a funny little thing – I think it was originally manufactured for chicken coops (the manufacturer name is Buckeye Incubator Co.) and intended to run on coal. It’s a really tiny little thing, and we ran the stove pipe out the window on the southeast side of the house. The whole setup screams “rinky dink” but it works!

We’re able to get the house up into the 60s in under an hour (in the furthest area of the house away from the stove — of course it’s warmer nearer the stove.) The house temperature drops to the low 40s by morning when it’s under 20 degrees outdoors at night.

Without the stove going, the house remains in the low 40s during the day, but like I said… we can get it to the low 60s in under an hour of firing the stove. It’s not bad. My body is pretty okay with less than ideal indoor temperatures, thankfully.

I am now reconsidering the whole rocket stove setup, and I’m pretty nearly set on tearing out the entire stove and cob bed, which is no small task! But seeing how well this little woodstove performs in the cob house, I imagine a nicer stove (such as the compact Jotul F 602 CB) might be a reasonable choice.

It feels like a cop-out to get rid of the rocket stove completely. I really want a working rocket stove, but I’m unsure if I am willing to get through the effort of rebuilding it. I think the bed is a lost cause and would have to be removed anyway. (It’s wayyy too much mass for the stove!) So it’s a lot of work either way. I love the concept of a rocket stove and think it’s ideal for a massive, completely cob house such as my own — heat storage is a huge benefit when you don’t have much insulation! But I think a nice, little and efficient wood stove such as the Jotul might not mean that we have to burn that much more wood for the heat we gain.

It’s sad to say that the rocket stove is a failure, but it’s a learning experience, for sure. I have learned a lot through building it and using it (when it did actually work). I would love to build another one again, but I don’t foresee that happening in the house. It looks like we’ll be going the cast iron wood stove route.

An update! (A brief one for now)

ziggy — Fri, 29 Jan 2010 02:36:18 +0000

After a week of travel in early January, I returned home to Dancing Rabbit… to cloudy, gray, cold Missouri. After days of thick clouds, the Common House’s power system was depleted and we went powerless (for the first time on this solar system) for five full days! Whoa.

Anyway, I have a fair amount of news to write about, but I have an inbox full of email to get to… It’s piled up after not being checked for two weeks…

But once I have a cool minute, there is some news regarding the rocket stove, winter conditions in the cob house, and future plans for home heat. Stay tuned! It’s been an interesting past couple of weeks…