Many problems I see with your kickstarter idea. I have been dwelling the past several months on a much bigger idea, yet much smaller as well.
Here's my take so far on what I'm trying to research the idea for.
A fireproof, rustproof, rotproof, rustproof, insectproof, rodentproof, waterproof, hopefully fireproof and bulletproof all in one house which heats itself, provides its own water and hopefully even(still a long ways off on this) provide its own source of power(non solar, wind, or hydro). Everything will be contained in a structure which is secure, not a homestead but a securestead.
My idea as it currently stands, it keeps on evolving all the time into something much better:
Fiberglass structure, no wood(wood burns) and very little to no metal(rusts). The fiberglass is waterproof and can be structural enough when used with regular sheet insulation to make it so you can make non standard walls(not vertical but slanted walls).
This is a small house, under 32 sq ft, no permit necessary and no property tax assessment.
The bottom level will have an air gap between the ground and the floor of the compost pile/house. The air gap prevent any worries about radon gas(5-6 miles north of where I live is known for uranium deposits).
The compost pile will sit with a lightly insulated fiberglass housing. It will have a door on one side for removable of compost and also to let the heat out during the summer months.
Above the compost pile will be storage space, probably 2-3 feet thick, this is closet space for the house right above it.
Right above the storage area will be the main room of the house, no walls. other than the outside walls which both inside and outside are made of fiberglass with R50-60 insulation between them. The outer wall would be much thicker than the inner wall. The heavy insulation is for both keeping the house warm but also to make sure the heat wants to move one direction only, upwards.
The walls of the house turn lean outward at an angle. The angled walls are used for both shade against the walls to keep the UV light down, since UV likes to break down fiberglass, but the angled walls also help to create more garden space up on the roof. of the house. The angled walls also make it harder to try to climb the walls to get to the door into the house which is on the roof.
There are no windows in the walls, and the front door is also not in the walls. This makes it difficult for someone to break in and steal anything or take any of your food unless they bring a nice big ladder with them so they can get up on the roof. Being built out of fiberglass it won't burn as easy as it would if was built out of wood. Also by being built out of fiberglass you aren't limited to the confines for insulation like you are with wood and you don't have the heat loss due to the wood interrupting the insulation in the walls.
On top of the house you have the rooftop garden which can be covered like a standard greenhouse. Only now it is protected from prying thieves due to it being up on top of the house. You have quick easy access to it while in the house since you go right by it every time you come or go from house since the front door is up on the roof. You need to manufacture a quick release/quick(small) storage ladder scenario so you can easily remove the ladder and take it with you anytime you leave. This further protects the house and greenhouse/garden from thieves, and animals.
Down in the compost pile you have a tank, which receives all liquid waste from the house this liquid waste gets heated up and rises up into the house and recondenses into fresh drinking water. At the same time a pipe through the floor/storage area which goes down into the compost pile receives all your shit for the compost pile/wastewater tank.
Everything is compact in design and the flow of everything works the way it is supposed to and gets rid of all the complex plumbing and heating problems associated with standard houses today.
The heat from the compost pile rises to heat the house. The heat from the compost pile warms the grey water tank and causes it form condensation which also rises into the house where it recondenses into fresh water. The heat from the house continues to rise to the ceiling(still not sure how much insulation I would want in the ceiling given the rooftop garden). Once the heat from the house leaves the ceiling it warms the rooftop garden which is also helping to insulate the structure underneath it. Now put a simple greenhouse on top and you should have close to a year round greenhouse out of reach of most people and animals. The only trouble would be providing enough sunlight during the winter months to keep anything growing all winter long.
This is a day and age where protection is far more important than having an item. You can have a car but if you have no electricity or gas supply, what good is the car to you. You can have the garden/greenhouse but if your neighbors/rioters/looters can come and take everything from it and leave you with nothing--than what good is it?
The biggest problem with your design shown on the kickstarter page is the simple fact of it sitting partially buried in the ground. That leaves it totally unprotected from troublemakers, which there are plenty of anymore, with many more being added each day. Your design needs a secure method of protecting the garden/greenhouse or what is the point of building it in the first place? You can't make a point of the idea being feasible if everybody has stolen all the food from the greenhouse.
Remember your old forum posting about cutting your heat bill by 87%. Why not get rid of it entirely. The trouble with your way of approaching it is space. Space is the dumbest frontier, not the final frontier. The more space you have the more it takes to heat up the space. I have lived in a 468 sq ft shack for 20 years now but stumbled into the tiny house concept back in '13 or '14. I trimmed my living/heating space down to 48 sq ft and wrapped the 6 walls with R60 pink panther insulation. I spent a couple of years in that room before shrinking it on down to 32 sq ft and lived in it for two years. Both years included R30 in the ceiling with the second year also including R30 in the floor. Last summer thanks to your 87% posting I shrank the room down to around 50 cubic ft with R60 completely surrounding the room. Unfortunately I didn't get the chance to try the room out this past winter since right after finishing the room I moved in and started full time caretaking for a friend of mine. I've been hoping to completely get a setup made where I could 100% eliminate the heating bill other than body heat and stray electricity from lights and a laptop computer. Typically during the summer months I only use 4-6 Kw /month, aka laptop and light. I need to get rid of the heating bill 100% and then I'm doing pretty good, but not until then.
I think the idea I'm looking at now is far more along the lines of what I'm hopingto accomplish with a lot of side benefits to it as well since I live with plenty of deer which love to eat the garden. I also have tons of mosquitoes and I have recently heard of the possibility of getting rid of the mosquitoes by moving everything up off the ground. I hear they don't like it much above 5-6 feet above ground. If I could garden or sit outside on a nice summer day and enjoy without having to deal with the bugs, because I'm above them then I win.
Still not sure about the electric generation but I am thinking something along the lines of using the evaporating/condensing water cycle for it, not sure how I could though with such limited production. Everything, in this day and age, needs to be completely self-contained and secure or else you have nothing.
Edward Lye wrote:I read this book about the construction of China's railway line to Tibet. "Methods included using pipes called thermosiphons along the sides of the tracks to refrigerate vulnerable parts of the soil along the highest parts of the plateau, an area that comprises the largest continuous sub-Arctic permafrost region on the planet. These cooling sticks are 7.6-meter-long steel tubes drilled into the soil; they contain ammonia, which draws latent heat out of the soil as it evaporates. " Might this be an alternative to that hole/trench? It has no moving parts.
Mike Haasl wrote:My design suggestion is to massively increase the surface area between the deep soil and the greenhouse interior.
Mike Haasl wrote:With any underground tubing, I think we can learn a lot from the Citrus in the Snow and the CRIMPI approaches. They have fans and TONS of ductwork in contact with deeper soil. This application is completely different but it's worth keeping in mind the scale of what they need to do to harvest heat from soil. Many many many square feet of surface area. With forced air movement.
Kyle Bob wrote:I don't understand how the thermosiphon works to cool the greenhouse.
Kyle Bob wrote:I don't understand how the thermosiphon works to cool the greenhouse.
Greg Martin wrote:
So it sounds like their thermosyphons are a form of heat pipe? Heat pipes utilize gas phases to very rapidly move heat in the vapor phase from a warm source and deliver the heat to the cold spots by condensing into liquid, which delivers the heat through the phase changes. If ammonia were to leak it would kill you, so another fluid would be desirable, but one that works at the right temps. The CRIMPI system relies on water vapor to deliver the heat to the earth battery, which provides the added benefit of dehumidifying the greenhouse air. Using water is very attractive. For example, you could channel water down the inside glazing at night into a rain gutter that would deliver it back down into one of the pipes. Since this system is a greywater treatment system their should be a good supply of water into the system to make up for any lost to the deeper ground. Paying close attention to the water cycling in this system would be a VERY good idea as it may be critical to the efficiency of the system. I'd very highly recommend using sensors that measure and log both temperature and humidity in the key locations of the system to understand how it's really moving heat.