Monday, November 19, 2012

Solar Greenhouse Research -- No Heat Needed

Here are three solar greenhouse projects just added to the site.  One in Missouri, another in Manitoba, and our new solar greenhouse in Bozeman.

Solar Greenhouses are roughly defined as greenhouses that can grow things through the winter without supplementary heat -- that is, they are 100% solar heated.

A University of Missouri Solar Greenhouse with 18 Year Track Record

This is a greenhouse I ran across while looking for a good design for our own solar greenhouse project.  It was designed and built by the Univ of Missouri extension about 18 years ago, and has been used for researching winter greenhouse growing since then.  
Its designed to work well through the winter with the steeply tilted, double wall glazing, the north roof sloped to reflect light on the growing area, all surfaces insulated except the south glazing, and thermal mass in the form of water barrels.

It successfully grows through the winter with no supplemental heating.

We liked it enough to model our solar greenhouse (see below) generally after it.


Solar Greenhouse Research in Manitoba

These are some articles and a paper on a solar greenhouse research project in Manitoba.  Part of the project involved taking a wide greenhouse and subdividing it into 4 separate, side by side spaces.  Each space was used to test a different glazing or insulating scheme through the winter.



Solar Experimenation "Thing" in Montana

This is our new solar greenhouse project here in Bozeman.  It is actually a scaled down version of the U of M greenhouse above.  

While its intended to be our greenhouse for the long run, we plan to first use it to do some testing of the performance of low thermal mass sunspaces attached to a house and used for space heating of the house, and then for testing the idea that it possible to build a small (tiny) room in one end of the GH that will be able to maintain a comfortable temperature through the winter on just solar.  This is a tall order in our climate, but we will see what can be done later this winter.

The GH with its 60 deg tilt, south facing glazing -- all other surfaces are insulated.

Building the frame

Temperatures in the first three days after being closed in.
30F outside -- 120F inside.

Any ideas or suggestions on this project would be appreciated.


Gary

2 comments:

  1. The University of Missouri design was similar to a design that I was working on about one year ago. We abandoned the idea after we added up the expense and found we had inexpensive alternative. I started with single wall of glazing facing south as the sun is mostly south here in Pennsylvania. We have a single corner of our yard that receives all the available sunlight on every day of the year.

    ReplyDelete
    Replies
    1. Hi,
      How do you prevent excessive heat loss from the east, north, and west walls and any unglazed ceiling?

      Gary

      Delete

 
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