Dave Turpin

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since Dec 07, 2012
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Groton, CT
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Recent posts by Dave Turpin

Are you just going for the look or are you looking for more thermal mass in the house?

The simplest solution for the look would be to anchor mesh to the concrete using concrete screws, then affix the stone facing using mortar. Special mortaring techniques are required for big stones, though.

If you wanted a 11' tall rammed earth berm... Well, that is an engineering challenge and I am afraid it would be prohibitively expensive.
8 years ago
Erin, you are in Lander? Do you know my uncle Ralph Allen? His family (now 3 generations) have lived there for as long as I can remember.

I agree that a lot of the "math" doesn't add up. That doesn't mean that it is unfeasible, however. Earthships simply must be built fairly large to be self-sufficient, and they will never be self-sufficient for food, something any builder of an Earthship must understand. 3200 square feet of roof may sound big, but how big is that really? Let's do some quick numbers.

The living space inside the Earthship is only a part of the roof. Let's say a family of four needs a conservative 1500 square feet of living area. This could be 75 feet wide by 20 feet deep. Now using the recommended form factor for the greenhouse, you would need an additional 10 feet of greenhouse in front of your living area. Now the cisterns. After accounting for the depth of the cisterns, the insulation and berming, and if you were to put the "drain" into the cistern as far back as possible, (not forgetting that the Global design cisterns are too small and will need to be amped up), you have about another 10 feet of roof space.

Adding an overhang of 2 feet, a slope of 7 degrees, and you now have a roof area of 3173 square feet. It is feasible, you just have to eek out every square foot of your roof that you can. Now, if you live in a rainy area, it is easier.
8 years ago

allen lumley wrote:

For historical accuracy it must be mentioned that all early Telegraph Communications - like those used through-out the U. S. Civil War, and as the long-lines
communication that supplanted the "Pony Express " (Whose "Hey-day'' was less than two calendar years beginning to end !) was designed and used to generate
its energy from an earth based galvanic reaction between the Cathode / Anode plates buried in the ground.

I agree completely. What I was saying is that the design shown above will not make power FROM THE PLANTS. If anything, it will make power by galvanic corrosion, as in telegraph lines. Some unscrupulous person, on the other hand, may try to sell this design to someone with the advertisement that it IS creating power from the plants, IMPLYING that the anode and cathode won't quickly corrode away. If someone says, "Come on, I don't believe you. Show me that this makes power." The scammer will hook a voltmeter up to the anode and cathode and show voltage potential! But that potential is short-lived and has nothing to do with the plants.
8 years ago
Sure, but why use pumps? Build your water heater to utilize natural circulation.
8 years ago
There is a serious problem here: For a battery to work (and this is decidedly a battery), you must be able to "intercept" the free electrons in the chemical reaction in order to get current flow. Yes, there are definitely electrons moving about in a hydrocarbon reaction, but those electrons are moving from the water molecules to the hydrocarbon molecules as they are formed. Stabbing an "anode" and a "cathode" in the ground will do nothing to capture these electrons, and I would be willing to bet that any demonstration pieces that exist will be using either iron and zinc or copper and iron electrodes to create ACTUAL electron flow by means of a galvanic reaction of the electrodes themselves (this is, after all, how a battery works), in order to trick investors.

In this diagram, basically the "plant matter" is just the electrolyte from which the electrons pass from the anode to the cathode.

If you actually wanted to intercept the electrons from the hydrocarbon reaction, you would need an anode made of water, another anode of oxygen, and a cathode of hydrocarbon. Of course this cannot be done, and even on a very, very large scale, there is never a electrical potential developed in plants, otherwise trees would shock you.

That said, there is nothing that says you cannot use the waste heat from this reaction to power a thermoelectric generator. It would be horribly inefficient, though.
8 years ago
You're bermed in with crushed stone? Did you crush the stone yourself?

Just wondering. I like the thought of using materials from the site, but in some places (like New England) the soil is usually very thin with large boulders and bedrock not far below.
9 years ago
One unfortunate fact leads to further discussion:

Despite the fact that the technology has been around for more than 40 years, no commercially viable engine has yet to be made.

Why not? Well, the reason is right there in the research paper from the 70's. Nitinol engines are about 4% efficient (absolute). By comparison a Sterling engine can be up to 30% efficient, almost ten times as efficient, and Peltier bridges, which have no moving parts at all, are up to 8% efficient, still double what the Nitinol promises.

Now there is one use that I can see for Nitinol engines: Despite their low efficiency, they can create power at very low temperature differentials. So you can conceivably extract power from huge amounts of "warm" fluids vice small amounts of hot fluids.
9 years ago
I have always been a proponent of the Earthship concept as more than just the Earthship Biotecture Global Model design and their ilk. I actually just finished my Master's Thesis on the subject and have designed a concept which meets all of the tenants of the Earthship while also being able to be built, to code.

I will spare the gruesome details, but ultimately, and keep in mind that this is only my opinion, that as long as the Earthship tenants are followed (as closely as they ever can be followed), it does not matter how the Earthship is made.

Thus, instead of packed tires, you can use insulated concrete forms. Does just as good of a job, but building code supported.

Instead of off-grid solar systems, you can use the grid, so long as your energy use is offset by sustainable production somewhere on the property.

And, to heck with spending a year of backbreaking work pounding dirt. Feel free to use machinery.

Michael Reynolds came up with the basic idea of these designs in a time when no recycling existed (at least in the US) at all, and it made sense to reuse as much as possible. In my opinion, building a home which will not fall down in fifty years meets the same purpose.
9 years ago
Many professional and amateur cyclists are now using the ISM Adamo racing seat (in its many incarnations)

Basically the seat lacks a nose so that all the pressure is on the pelvis instead of the perineum.

It's all personal choice, though. I ride hundreds of miles on a seat with a nose and have not yet had trouble having kids.
9 years ago

Dedfa Noyb wrote:All anybody seems to agree on is that I should not use diaper water in a greywater system.

There is a simple reason for that. Diaper water is not grey water, it is black water, and should be treated as such.

If you build your home with separate grey water and black water treatment paths, you must route the sink or machine that you intend to clean the poopy diapers into the black water. Personally I use a 2-step process: Clean the bulk of the poo off in a deep sink (black water), then final wash and sterilize the diapers in a washing machine with a steam sterilization cycle. In my case the effluent from the washer DOESN'T go into a grey water treatment area, but I believe that it could.

This requires an expensive HE washer with a sterilization cycle, but it kills two birds with one stone: The diapers are sterilized for my kids and the effluent from the washer is also sterile.
10 years ago