Making use of
recycled materials and the cast offs of others I was able to build a solar
greenhouse that provided:
1. All the vegie and
bedding plants that I needed for my gardens.
2. Salad greens and
strawberries through all but a few weeks of the winter.
3. Supplemental heat
for my home which resulted in a 30% reduction in my heating costs for
the season (based on comparisons of heating bills with my neighbors).
I'll be the first
to admit that my greenhouse wasn't the most beautiful structure in the world,
but I still found a lot of enjoyment and function in it.
two shots are of the sloping roof of the greenhouse. The seams that you see in
the shots is because each is actually two pics placed side by side. I wanted
to show it both with the night cover on and off. The cover was nothing more
than a queen sized quilted bed spread that was pulled up with rope and a
couple of pulleys. It served the purpose and cost only $10 to buy at a used
furniture store. The cover was pulled up as soon as the sun was low enough in
the sky to no longer produce enough light for heat or photo-synthesis and was
taking off as soon as the sun was up in the morning. On cloudy/snowing days it
was left on. The snow actually shook off nicely.
shots of the barrels that I used for thermal storage. Thirty-gallon drums that
were filled with water and painted a flat black. Shelving was put on top of
them to use for the plants and to hold back some of the heat. My goal was to
keep the greenhouse at as constant a temperature as possible and this way the
heat was dissipated a bit more slowly allowing for a more even temperature
over a twenty-four hour period. I used pop cans where the barrels touched to
pick up just a bit more solar heat and ground corn cob on the ground kept my
shoes a bit drier and bounced the light back up for the plants.
I'll be adding
more pics as I plug away at this project, but I wanted to share this one with
you yet. It shows some of the Flowering Maples that I was training as
standards. As you can see, even in the middle of winter, they kept blooming
like crazy. They loved the greenhouse. Remember, this was in Minnesota, in Mid
January, in an UNheated greenhouse!
I was fortunate
enough to come upon a quantity of aged cedar from a home that was having the deck replaced.
During my garden
research I'd run across a lot of information concerning greenhouses. Which led
to my going on to solar greenhouses... and so when the offer of free lumber was
made it didn't take much thought to know that not only would I take it, I already
had a use for it.
It took about a week lay out a design that would fit the location and the
available space and make the best use of the materials that I had available to
me. I was able to obtain most of the materials at no cost by recycling the cast
offs of others.
Some old storm
windows became the short south wall, the built-in screens allowed an easy air
intake for warm weather climate control. Some old metal
barrels, scrubbed up and painted became my thermal storage. Old shelving and
paneling and scrap lumber became the shelving.
I built it myself..
and considering I had absolutely no experience - I was pretty proud of it when it
was completed. The trickiest part was the Dutch door. I decided that it would be
nice to be able to open the top half of the door on nice days when I was working
inside, leaving the bottom half of the door closed to block out the drafts...
Maybe I don't quite understand all of the physics of it.. but it worked.
enough thermal energy to maintain itself without any input from me as far as
2. The excess
heat produced during the day was drawn into my home by using a fan
with a thermostat set to start when the temperature in the peak of the
greenhouse reached about 80 degrees.
3. By making
use of the free heat - heating costs for the home dropped by
approximately 30 percent over the heating season.
4. It produced
salad greens throughout the winter and alpine strawberries most of the year
'round. (December and January they slacked off a bit until light levels came back
up... I used no supplemental lighting during the short-light months.)
5. My last winter
there I started experimenting with the cold greenhouse varieties of cucumber and
tomato. Results were pretty good.
6. It also produced vegetable and bedding plants enough for my own use
with enough extra to be able to sell or trade for supplies; replacement soils,
soil amendments, plastic covering (changed annually), paint and replacement
By using thermal storage techniques the greenhouse was able to maintain a more
constant temperature, on it's own. The heat picked up during the day was
absorbed by the water used as thermal storage and was vented into the home. At
night heat was given off by the water barrels to keep the greenhouse warmer,
without having to pay for any type of heat supplementation.