Jenn wrote:
On 9/19/2014 5:48 PM, David Hare-Scott wrote:
Jenn wrote:
Is this the right group to discuss Aquaponics and Geocentric domes
for greenhouses?

Or is Rec.gardens a better group?

thanks.

It wouldn't make much difference, this NG has more emphasis on fruit
and vegetables but that is not OT on the other group. On aquaponics
there isn't much talk on either. On geocentric domes there is
unlikely to be any at all. If you mean geodesic domes that could be
more fun.

You're right ... I meant geodesic domes.

I would be surprised if there are too many commercial greenhouses that stray
from either box structure or arched roof design. I gather there are some but
you need to ask why you want one.

DIY greenhouse designs are mainly hoop houses. That is a rectangular floor
plan with an arched roof and sides built of bent members - usually polymer
tube. You will find many plans for these on the web. They have the
advantage of being fairly cheap and simple to build out of commonly
available materials.

Geodesic designs allow you to have a roof with no internal posts at the
expense of the self-supporting dome shell being constructed out of planar
polygons - mainly triangles. It is hard for me to see why you would bother
as there is no particular problem with internal posts in a greenhouse and
making a self-supporting dome out of triangles requires unusual structural
members and forms that are not at all readily available and that would be
quite hard to fabricate yourself. Another issue is the covering would have
to be manufactured by joining many triangles together. This is an added
expense and every seam is a point of weakness. In the more traditional
designs the number of seams is far fewer depending on the size of the house
compared to the size of available polymer covering.

If you are going for the coolness factor or you have some special aversion
to internal posts by all means but I am yet to be convinced the design is
very cost effective for this application.

--
David

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