Keeping large greenhouses at constant temperatures can be costly during those parts of the season when sunlight alone is not enough.
So why not design a greenhouse which expands to suit the need?

I want to make an Hoberman hemispherical greenhouse on wheels.
When retracted the folds in the polly will condense and collect water which is gravity fed to the counter-balance weight/ internal water reservoirs which use the weight of the water to extend the individual triangular pantograph sections against spring-powered retractors and expand the dome incrementally as the summer progresses.
The outer garden beds along the inner periphery will also move outwards as the dome grows but because they cannot expand themselves the spaces between the beds grow instead.

Inner concentric garden beds are touching one another with a single walkway through them when the dome is contracted but are also tugged outwards against a slight upwards slope so that walkways appear and widen between them as well.

This would conserve energy at times of the year when the entire greenhouse is not needed and allow taller plants at the center to reach their maximum height and wider plants in other beds the width they need to control fungal infections and still allow easy access for the gardener.

At the end of the season gravity and the spring loaded triangles collapse the whole contraption back to its original germination house size.
-- 2 fries shy of a happy meal, Nov 14 2018

+ sounds like it's beautiful!
-- xandram, Nov 14 2018


It's collapsed in the winter? The surface area will stay the same, as I'm imagining it, but the volume will be much less when it's collapsed. Therefore, in the winter, it will have a higher surface area-to-volume ratio, and be less able to conserve heat. (The spikiness will help to reduce the wind over a large portion of its surface, but natural convection in the free air above the dome will be largely unaffected.)

[+] anyway because it's just cool.
-- notexactly, Nov 14 2018


//Hoberman

Dammit...I was going to say that...

Extra points for using Hoberman Switch Pitch's to cushion any falling produce. Oddly enough SP's used to be about 60p/80 cents..
-- not_morrison_rm, Nov 14 2018


Hi [xan]. Thanks eh.

[notexactly] If the inner folds remain filled with liquid during the winter then the surface area is not that of the folds themselves but that of a ... I can't think of the right word, like an Aztec pyramid if it was circular.
The heat will get conserved just fine I think.

Those Hoberman Switch Pitch's have been tickling the back of my head for quite a while now.
There's something to it which has bigger applications I haven't learned enough to figure out yet.
-- 2 fries shy of a happy meal, Nov 15 2018


Well, the SP's would be good for impact situations, as flipping to other state takes up energy. Heavier construction material -> more energy dissipated?

Gain kudos for having a fractal layer of SP's on the inner and/or outer surfaces of the SP.

(tries to remember which sf story which has the tool which turns impact energy 90 degrees, Moties maybe?)

NB have some sharp edges near the apexes inners, when closing the thing for winter, it'll do the dead- heading for you.
-- not_morrison_rm, Nov 15 2018


Hi Zanie, good to see you. I agree the idea is beautiful. Don't know if the specifics are actually doable, I'll leave that for the architects amongst us.
-- blissmiss, Nov 15 2018


What [xandram] said. [+]
-- pertinax, Nov 16 2018


God, I meant xanie. Not Zanie. Zanie sounds like zany which sounds like a clown. And xanie is far from that. She is very deep and quite special.
-- blissmiss, Nov 16 2018



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