We just purchased a Clear Span Hobby Greenhouse and wonder if anyone
else has had any experience with these.

We are still putting it together after 3 days of fighting crappy
hardware, lousy instructions and generally poor design.

We don't scare easily but I sure pity anyone with any less fortitude and
tool knowhow.

It will be a nice greenhouse when we are done but I would be hard
pressed to recommend it to anyone.

We purchased a $25 one from Farm & Fleet just to test the practicality
of a small green house and fell in love with the idea. We already have
tomatoes ripening and all the plants we put in were 2-5 times the size
of our usual indoor starts.

We went back and bought a second one for "spare parts" because it was so
cheap but now decided to get a real green house.

The new one uses double walled polycarbonate which should insulate a lot
better and wonder if anyone has any idea of the possibility of keeping
this warm enough in winter with a one KW heater.

js


--
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On Sat, 16 Jun 2007 18:03:03 -0600, Jack Schmidling wrote:
We just purchased a Clear Span Hobby Greenhouse and wonder if anyone
else has had any experience with these.

We are still putting it together after 3 days of fighting crappy
hardware, lousy instructions and generally poor design.

We don't scare easily but I sure pity anyone with any less fortitude and
tool knowhow.


Jack, I don't know this company, but if you're really stuck, you might
try popping in at HGA-L, the home greenhouse association email list --
there may be someone else that has experience with this design.

The new one uses double walled polycarbonate which should insulate a lot
better and wonder if anyone has any idea of the possibility of keeping
this warm enough in winter with a one KW heater.

1KW root zone heating may be enough, depending on your climate and
the crops you're growing, and what you're expecting. Consider also thermal
mass to help carry you through the night hours.

There's a USDA program that allows you to "build" a virtual greenhouse and
test it for your parameters. I'm not sure if it can handle calculations for
a small house or not... won't run on the o/s I use.
http://www.ars.usda.gov/is/pr/2007/070607.htm
http://www.ars.usda.gov/services/sof...softwareid=108

Another possibility, again depending on your location and climate, but
a distinct possibility given your inquisitive nature and mechanical aptitude,
would be to add a solar water heater type design, possibly using a PV pump.
The new vacuum solar collectors are very efficient, but I think even Ye Olde
1970's homemade designs might be efficient enough.

One hint for small greenhouses in winter, if you can: Water with room temp
water rather than freshly pumped. A simple way is to fill a bucket or carboy
near the GH roof, and then let that warm in the house, and water with the
warmed water by gravity.

Kay

On Jun 17, 3:42 am, Kay Lancaster wrote:

Thanks for the tips and the heads up on SUBSCRIBE HGA-L .... I just
did.

One hint for small greenhouses in winter, if you can: Water with room temp
water rather than freshly pumped. A simple way is to fill a bucket or carboy
near the GH roof, and then let that warm in thehouse, and water with the
warmed water by gravity.


I am curious about this one. Is it a happy plant issure or are you
saying one can save energy this way?

The latter seems unlikely.

js

In article . com,
Jack Schmidling wrote:

On Jun 17, 3:42 am, Kay Lancaster wrote:

Thanks for the tips and the heads up on SUBSCRIBE HGA-L .... I just
did.

One hint for small greenhouses in winter, if you can: Water with room temp
water rather than freshly pumped. A simple way is to fill a bucket or
carboy
near the GH roof, and then let that warm in thehouse, and water with the
warmed water by gravity.


I am curious about this one. Is it a happy plant issure or are you
saying one can save energy this way?

The latter seems unlikely.

js

If you don't want to chill the ground with water from the tap (you know
the pipes are in the ground and the water will be the same temperature)
place a 5 gallon carboy (demijohn, whatever) high in the green house
where the warmest air will collect and warm the water you are going to
use on your plants. This will keep the ground temperatures up. Capice?
--
Billy
Coloribus gustibus non disputatum (mostly)

A little more information on root zone heating vs. air heating in a gh
http://www.umass.edu/umext/floriculture/fact_shee
ts/greenhouse_management/jb_root_zone_heat.htm (paste back together)
and
http://www.attra.org/attra-pub/PDF/ghrootzone.pdf
and
http://www.radiant-concepts.com/appl...eenhouses.html

There was a nice article laying out a lot of the pros and cons of
root zone vs air heating in gh work in an edition of the Ball Red Book
about 10-15 years ago. I don't happen to have a copy, so I'm unable to
get you a better citation... sorry.

Another tactic you might consider for winter heating is to bring back the
old hotframe, long a northern midwestern tradition when horses and
cows were plentiful. A hotframe is built much like a coldframe, but
with a much deeper pit. The pit is bottom-filled with a lot of fresh
manure, covered with a foot or so of soil, and then cool season crops
like lettuce, carrots, etc. are planted for fresh veggies in the winter.

Yet another approach was laid out in a book I read long ago called
"Winter flowers in a sun-heated pit". I was never in a position when I
lived in Iowa to build myself a pit greenhouse, but it seems quite logical,
and you've probably got appropriate soils in N. Illinois.
You'll probably have to interlibrary loan the book.

Winter flowers in greenhouse and sun-heated pit
by Kathryn S Taylor; Edith W Gregg
Language: English Type: Book
Publisher: New York, Scribner 1969]

or

Winter flowers in the sun-heated pit, including the
lean-to greenhouse as a complement to the pit,
by Kathryn S Taylor; Edith W Gregg
Language: English Type: Book
Publisher: New York, C. Scribner's Sons, 1941.

Kay

On Sun, 17 Jun 2007 21:24:43 -0700, Jack Schmidling wrote:
I am curious about this one. Is it a happy plant issure or are you
saying one can save energy this way?

You can probably save a smidge that way (if you're dousing the roots with
cold water, it takes a root zone heater a bit more to heat the soil again),
but mostly it's a happy plant thing, especially with seedlings.

Kay