Earth Oven and Greenhouse

[MoonRiver]

I'm planning on building an earth oven this summer. I have been trying to decide the best place to put it.

I could put it on the patio if I keep it small. I would have to cut down a small tree, but otherwise it should work out fine on the patio.

I could put it in the garden. My garden is all raised beds and I could replace one of the 4x4 beds with the oven. I think it would look nice in the garden and I could make it a little bigger.

Both of these are convenient to the back door, water, and work space.

I also have a concrete slab that was built for a trailer a little farther back on the property. I could build a much larger oven there if I wanted. I was also thinking of building a greenhouse on the slab.

So I am wondering, how could I use the oven to heat the greenhouse? Could I just build it so the back of the oven is part of the end wall of the greenhouse? Any other ideas?

[empofuniv]

I have no suggestions for you but sure would like to see pictures of your progress and finished projects!

Pam

[Drew Cutter]

If you use the earth oven you need to figure out how to regulate the temp. , too hot . Also , it dry heat which maybe bad for the plants.

[Wisconsin Ann]

I wouldn't use an earth oven to heat a greenhouse just because they're built to fire HOT and fast. although...let's think outloud...

If the end of your greenhouse is built of concrete block, which would absorb heat from the oven and then release is slowly during the night...that might work....thermal mass and all that.

anyway. I'd build the greenhouse on the slab, and the oven in the garden. And then a smaller oven on the patio Easy to throw pizzas in, etc for parties! Building in the garden would give you more room to store wood for it, also perhaps a roof structure? don't know how you're building the oven, but if it's adobe or cob it will need a roof.

[MoonRiver]

Originally Posted by Wisconsin Ann

I wouldn't use an earth oven to heat a greenhouse just because they're built to fire HOT and fast. although...let's think outloud...

If the end of your greenhouse is built of concrete block, which would absorb heat from the oven and then release is slowly during the night...that might work....thermal mass and all that.

anyway. I'd build the greenhouse on the slab, and the oven in the garden. And then a smaller oven on the patio Easy to throw pizzas in, etc for parties! Building in the garden would give you more room to store wood for it, also perhaps a roof structure? don't know how you're building the oven, but if it's adobe or cob it will need a roof.

Ann - That's the kind of thing I am thinking of. With a rocket stove, you build a bench from cob to hold the heat. I'm trying to figure out how I can do that with the earth/cob oven. Maybe there is some way I could have a bench and a way to control whether heat is allowed into the bench or not - some type of valve or a piece of metal or something I haven't thought of yet.

I'll probably give the oven a coat of lime for protection. Even uncovered, the oven will probably outlast me.

[ronbre]

myself i wouldn't put the greenhouse on the slab ..for my greenhouse i plant right in the dirt floor of the green house so i have mine in a garden..with soaker hoses to water the plants that are in the soil..i can keep plants in the soil well into December here in Michigan where it is..and they don't freeze..if it does drop too cold i can light a few candles to heat it over night .

as far as the earth oven..i really don't know much about those..but a solar oven might work well

[peacebaker]

I have the basic Kiko Denzer earth oven. No chimney. 7ish inch thick walls.

I'd choose a convenient site for the oven where you can see the fire easily for tending. The heating stage takes several hours of fire tending--not tons of work but you have to keep an eye on it.

As for heating--most of the heat during the fire is coming right out of the door. Extremely hot (eyelash burning hot, I can attest!). But the rest of the oven stays relatively cool on the outside for a long time. I can tell my oven is about ready for baking when the exterior is just starting to get warm. The heat really takes a while to soak in. An hour or two AFTER the fire is out the exterior is quite hot, and the next morning can still have a residual warmth to it.

Hope this helps. I had a hard time imagining how it would all work before I built mine. I don't think it would be ideal as a main heat source for something like a greenhouse, but I guess you could use that residual heat for something...

Also I found it useful for siting my oven that the exterior is not that hot during firing. IE I have mine sited with the back to a wooden fence (about 3 feet away) and have no concerns about heat damage. We even have grapes growing over the roof of the oven, and except for vines right over the door, it's not a problem for them.

[raymilosh]

My friend Joe is helping me build an earth oven in my yard. It's functional now, but has yet to be finished so it looks nice.
Anyhow, on to the advice.

it is HEAVY and it is going to last forever, so I would recommend putting it on a solid foundation, not on a wood foundation. And take the time to make it something you will enjoy seeing for the rest of your life

put it near where the firewood already is nearby

put it where it will be convenient and pleasant for you to use, perhaps at the edge of an outdoor social area.

consider putting it in a place where it will be protected from weather and where you can use it regardless of weather. consider building a roof over it.

face the opening away from prevailing winds.

insulate the bottom from earth and the top from the atmosphere to improve its performance

don't vary much from the standard designs if you want it to perform well. keep the height of the opening right around 60-64% of the height of the interior ceiling

fire the oven before completing the exterior finish so you can see if it needs more mass to work well

ENJOY IT. Make Pizza, Hard breads, soft breads, casseroles and cookies and brownies all in the same firing

there are many ways to finish them and construct them. Mine is basically standard masonry foundation, base and finish, but the oven itself is earth (cob), not masonry. I'm finishing mine to look like a little house, like most of the ones in this website.
http://www.traditionaloven.com/ovens.html
It will be basically zero maintenance and last forever and be beautiful. The exterior will be a cement based mortar and the roof will be tin and the roof will be cantilevered over the working area. I'm pretty excited about it.

[Wolf mom]

See the thread on solar greenhouses & don't worry about trying to save your plants in the winter & then cooling the greenhouse in the summer.

Just have fun with the earth oven. They're really two different things.

[Wisconsin Ann]

For the bench heating...that's done with a flue that goes around the oven and under the bench. There's a damper that you open to allow the heated air into the bench flue.

The problem with trying to do that with an oven, is that the oven is meant to be hot on the inside and cool on the outside...extreme insulation. I don't know if you could reroute the flue....a double flue perhaps...one going up, another going into the bench..with a damper on each to determine which is open?...just remember to leave an opening so you can clean it.

You may find the MHA site helpful (LINK to the gallery with further links). They're mainly doing brick/concret heaters, but many links to ovens, adobe, etc. I like this one about making adobe bricks to build your oven:http://heatkit.com/html/bakeov02.htm
http://www.frankspizzaoven.com/ is from a man who build a "loam" pizza oven. Pretty complete site if a little WORDY!

[Wisconsin Ann]

I've been thinking more here...and I agree with WolfMom. Just enjoy your oven...don't try to make it into a Masonry Heater/rocket stove. If you're building in cob, it's not costing much except in time....perhaps an oven in the greenhouse with a concreteblock or brick surround to control heat could be another project?

[MoonRiver]

Lots of good advice. Thanks everyone.

I think I will build it at the back of the garden. I can start on it now and only have to move a couple of tomatoes. Still working on the design.