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Designing a Solar Greenhouse . . . suggestions?

PostPosted: Jun 21, 2005 10:22 pm
by Homer_Zn5
Okay, I have gotten the go-ahead from my wife, and have been reading The Solar Greenhouse Book by McCullagh. I have decided to make a pit greenhouse 10' x 16' with southern glazing only (twin wall polycarb seems pretty cost effective, with vinyl sheet on the inside), and earth berm on the north wall.

Does anyone have experience with this type of a system in the Midwest? how warm will one of these stay in Jan/Feb without added heat? I would prefer to not have to insulate the south wall every night, and may simply stick to using this greenhouse to bump me out a few zones so that I can raise carnivorous plants a little more quickly and without fear of high winter mortality.

Does anyone have any pointers? I'm probably going to use old tires packed with dirt for my structural walls (ala earthship design) and simply us crushed gravel for the foundation and floor. I'm still playing with what to use for heat storage . . . either 55 gallon drums or gallon jugs stacked appropriately. I was just hoping that someone here could give me their experiences in Zone 5.

Intrigued by the idea

PostPosted: Jul 06, 2005 9:08 am
by DryGulch
Homer I have always wanted a green house and have been very intrigued by the pit greenhouse. I unfortunately do not have the space.

I have discussed this idea and will give you some of my insights.

Here in zone 4 on the edge of 5, we grow a lot of potatoes. In the old days... 1860 through the 1940's people would have root cellars to store them so they wouldn't freeze. My grandfather had an enormous "cellar built into the side of a hill where he stored apples and potatoes. It did not have any southern or solar exposure (only a larger than standard heavy door actually exposed). The temperature did dip into the 40's, but seldom colder.

My girlfriend built her house into a hill with a southern exposure, windows all across the front. She does have a wood stove, but fairly small. At over 3,000 square feet, she only needs a fire on the extreme cold days, where it does not get above freezing for the most part. They added on a huge addition, a lot more above ground, and their heationg bill was $400 last year for wood.

PostPosted: Jul 06, 2005 9:56 am
by wishiwere
Wow! I'm always intriqued by what people can do with the earth when they put their hearts to it!

PostPosted: Oct 19, 2005 5:53 pm
by notmartha
here is mine and its made out of recycled windows and wood!

total cost 250.00

Re: Designing a Solar Greenhouse . . . suggestions?

PostPosted: Apr 14, 2010 12:39 pm
by Lseven
I'll try cross posting this here as it is a bit more applicable and may not be getting approved for the other thread.

I am thinking of building a greenhouse with a insulated tall wall painted black on the north side. On the inside of that wall I was thinking of affixing black water filled pipe zig zagging back and forth 10 or so times starting with a line coming in one side on the bottom and ending with another line going out on the other side at the top. The pipe would be on a black surface and fully exposed to sun through the sloping clear roof and glass on the south facing wall. The two lines would go down to the ground on their respective sides and split into 4 or so smaller lines that would run across and then join up again and into the line on the other side. I would cover this bottom pipe with a foot or so of cleaned 1-2" gravel.

This just seems fairly cheap and hopefully an effective way to store heat without taking up room in the greenhouse. The gravel would also be functional to walk on and absorb any water. I think the mass of gravel would store more heat then drums of water and radiate upwards more evenly. I'm also hoping that the natural convection or circulation of the water in the closed loop would more effectively circulate heat into the gravel heat sink then just a passive drum of water would do.

I'm also looking for input on this idea and essentially am looking to do the same.... extend my zone somewhat. I'm near Calgary which I believe is the sunniest city in Canada. The coolest nights are usually the clear ones and really I just want to take advantage of good early growing but still avoid the late winter storms (and frost) we can get well into May sometimes.