eyelid concept for a greenhouse

[boatkinson]

Actually incorporating principles a creature's eye in this case to enhance photosynthesis....

Assuming one link is allowed, here is my plan to build this summer (in Maine USA)

http://www.midcoast.com/~bo/EyelidGreen ... House.html

The page illustrates the concept for a self heating design based on annualized heat storage. New materials will be limited to new plastic sheet on the south side only, retractable foam eye lid for cold night, some metal rods and a little bit of portland cement. The opaque north side will be modified paper-mache from recycled paper. Ground insulation, one key to annualized heat, will be recycled cardboard (instead of expensive foam). After all, it also is a risky plan because my site is wet, here in rainy Maine.

I tried for years to get into the self-heating-house business, but the market is fairly conservative and my only promotional efforts are web based. Credit where it is due, such principles can be googled, to see the basics have been proven in cold Montana, USA--

Yet a means to push climate zones in cold regions, without a fuel, deserves, i should hope a small post here or there. Especially now that selsuficient-ish people may have to intensify efforts in these economic times.

Glad to join your ish group. ^_^

[Green Aura]

Looks complicated!

[Colin]

Hi Bo
Mine is along similar lines.
The interesting part is keeping the door enty and ventilation accessable 24/7 without compromising the insulation. Making everything modular so it can fit through the door and/or be removed for the summer.
Is it built yet?

[Ellendra]

Looks incredibly complicated, definately not something I'd want to build.

[Colin]

It would be a lot of fun to build and even the kids could help with the lower sections
If its 30ft in diameter, anyone that can manage a single tube 30" long could build it..assuming they can reach 15ft high

[boatkinson]

Hi All,

Admittedly, i like a good challenge but the main objectives in my eyelid concept is frugality along with warmer conditions in frigid winters-- That is really the complicated part. Frigid winters, brrrr. So many desirable plants can't stand up like kale for example which sort of hangs on, in ordinary cold frames, but does not flourish as well as it would if warmed 24/7.... Annualized heat storage has been proven over two decades, now. No complications, once a summer's heat is really saved up conveniently. The main invention here, by a Montana professor, circa 1980, was to insulate a whole house lot, not just the house, (so to speak). I should improve the diagrams to better show this. Lots of links could be googled, once we are laid off due to recessions. Once we find veggies are priced a bit too high. Let one's stomach decide if it is worth while.

I will add another link to the www page as summer progresses, to document actual building progress. My conditions are not ideal by any standard, but if successful, it may offer inspiration for people in search of productive avenues, in case of further recessions world wide. Industrialized food may or may not prove "less complicated", as evolution will rather indifferently let us fail, when leaders make poor choices for the masses.

[Colin]

Hi Bo
I admire your out of the box thinking, your project appears to be fairly large scale

Most greenhouses in the uk don`t use the most basic of perimeter insulation, so not too many would aspire to insulating the entire garden. Boring deep holes for pipework wouldn`t be that popular either.

The big hurdle is relying on the UK summer to heat the huge thermal mass, it would be a little like trying to heat a lake with a 50w aquarium heater. It may take a while

[boatkinson]

Collin,

Do you have a link which shows what you are doing. On Mar 24, you wrote "Mine is along similar lines." I would love to see your approaches and interests.

As i recall a few months spent in southern England, it was chilly enough to take an interest in warmth, in case one wished for warmer plants. More-so if the gulf stream alters it's characteristics according to climate models, tipping points, etc... Could England become more like southern Scandinavia or Holland? I'm not one to focus a great deal on climate models, but have instead acknowledged the importance of "being prepared", small footprints, etc... (Since 1974 or so, when scientific journals began reporting climate change issues, pollution, etc...)

Another issue i've considered is to provide summer openness, hence an "eyelid". Actually several "lids" if a simple pest screen is also counted on an openable frame. Or a frame alternately exchanged with plastic sheet for winter daytime exposure. It calls for more than just a shoulder width door on the north side. The thermal annualizing approach i will carry out is actually simpler-- My diagram needs correction for that. Blogging helps supply motivation for the writer's block ;-)... I'm using drilling with a hand held mason's drill. Trickle-down-solar uses gravity very economically to deliver summer heat to ground mass below. Water is clean tap water from a garden hose. Solar control will be similar to an automobile thermostat, no electronics needed. Simple solar pistons are adjusted for lifting insulation-eyelid in winter and switched to handle winter insulation lid for severe cold. One can simply use manual efforts as an option. Simplicity which i have actually used in my greenhouse and my domestic solar water collector for years (a simple gravity feed solar water tank for domestic uses).

BTW, my "house lot" insulation will be recycled cardboard, available at next to nothing, but sandwiched between layers of plastic sheet, (including some extra recycled tarps for cushioning). Indeed my labor tasks are extensive, but ordinary for a self-sufficient lifestyle. Yes annualizing does "take a while", but a low investment, besides some labor. My little eyelid will be 16 ft diameter, which might supply substantial veggies all winter. We have plenty of perrenials to add, as a future option. Does self-sufficient-ish imply healthy, vigorous work?

[Colin]

Hi Bo
I don`t have a webpage or anything like that.
My project has slowly evolved over time, i did have a gameplan initially but i tend to go off track as i get and add new ideas..which is why its still not finished
The dome is a little smaller than yours at 14ft dia x 9.5ft high. I designed and built the frame, which is based directly on the Eden Project in Cornwall. The triple wall inflated pillows appealed to me as i really enjoy a challenge
It sits on a concrete ring foundation with a short riser wall to provide a full 78" door height. The perimeter insulation consists of 2" xps board installed 2ft deep vertically, eventually the exterior beds will add a further 4ft of horizontal wing insualtion.

The heating and cooling solution consists of 15 sections of perforated tubing buried in two layers in the clay floor, the deepest being 4ft. A central plenum houses a 10" duct fan which can route all the greenhouse air underground in about 90 seconds, it has a feature which allows the air to recirculate underground in a closed circuit for experimenting. The fan is controlled by a speed controller and a homebrew differential thermostat which senses the difference between the air and soil temperatures. I have a 160ft2 homebrew air heating solar panel project underway to help capture more of the limited winter sun to route into the dome and thermal mass, it uses the existing plenum fan.

The night insulation is similar to your eyelid design except it rotates horizontally, pretty much like a observatory dome used for telescopes. One section is fixed to the north wall and the other section rotates to cover the south glazing. In the daytime the rotating section "parks" on the northwall effectively doubling the north insualtion value. The rotating wall is controlled by a homebrew photocell switch and two microswitches which will automatically close the insulation at dusk and open it again at dawn in around 30 seconds. My personal view is that greenhouse glazing is pretty useless in the dark except for losing heat

So there you have it, one mad scientists approach to greenhouse design
I`m looking forward to following the progress of your unique project, i`m sure you will have a lot of fun along the way
Apologies for the epic sized post.

Best wishes

[boatkinson]

Ah yes, the universal solvent!... Hindsight-creativity does very often provide good solutions I certainly rely upon that principle as well, especially as the day grows short.

I see we share a deeper than usual interest in such things. Thanks for your details. I am impressed with your side-ways eyelid for an insulating closure-- Apparently the animal kingdom also has examples--
http://www.harunyahya.com/books/science ... eye/29.jpg

Are you using some sort of fury wind-stop, for your sliding door?

I too like the basic hypocaust floor ventilator approach having made a ferrocement version for my home. Mine got invaded by long-distance-burrowing shrews, because FC was omitted at the base. I was trying to use low-pressure solar chimney power alone, without fans. The trickledown method is quiter though and ulmately may prove beneficial for plant stimulation as well. Have yet to learn what the shrews will make of it

Always glad to continue off-forum contacts, so as not to waste bandwidth here.
I hope a non-spam link is now and then permitted for illustration, with citation.

Lovely-ish forum style, thanx to management