Rob Meyer wrote:
With the wofati, you get:
1.) The use of locally abundant materials.
2.) Passive cooling.
3.) Minimal ecological displacement, since the roof is green.
With the earthship, you get:
1.) The use of locally abundant AND recycled/otherwise waste materials.
2.) Passive cooling AND heating.
3.) Minimal ecological displacement, since the thermal swale can be planted.
4.) Electricity production.
5.) Water harvesting.
6.) Waste water treatment and reuse with the added benefit of...
7.) Indoor year round food production.
Anyone have any thoughts on this?
Rob Meyer wrote: It uses recycled materials, i.e. bottles, cans, and mainly tires. By doing so, it removes these products from potential landfill, but it also removes them from recycling, which means more fresh materials will be required to continue to make those materials. On the other hand, if those materials were recycled into new tired, bottles, or cans, the mining of new minerals/extraction of new rubber could be avoided all together, so long as there is enough recycle-able material to provide these products.
Annually, more than 250 million scrap tires are discarded in the United States.
A report from 2003, cited by the EPA, says that markets ("both recycling and beneficial use") existed for 80.4% of scrap tires, about 233 million tires per year.
I have read that the average earthship takes about 2000 tires
Jami McBride wrote:
I only read about it, but apparently the tires do off-gas even when covered with soil. You can also google it.
to assess the risks to human health and environment posed by the use of recycled tires in Earthships, one must look at the pathways of exposure, and the state in which this potential contaminant exists. The letter states that, "A tire under proper conditions will break down into the above products." "The proper conditions" for rubber to degrade would be: high temperature, exposure to light, or the presence of strong oxidizing chemicals. None of these conditions exist when a tire is entombed in an Earthship wall surrounded by packed earth, vapor barrier, stucco, and paint. The argument has been made that tires must off-gas because "old tires smell." The reason "old tires smell" is due to the photo degradation of rubber. Essentially what happens is that photons from light bombard the rubber and knock atoms from the long rubber polymer molecules. This causes the rubber to degrade, and smaller molecules to vaporize. In the absence of light, this does not happen.
Tires are not exposed to light when used in an Earthship. In order for the tires to affect the indoor air quality of an Earthship, the tires must off-gas vapors which must travel from the tires, through the walls, into the living space of the Earthship. The production of such vapors will be proportional to the vapor pressure of the compounds producing the vapors. The NIOSH pocket guide lists the vapor pressure of carbon black as "0 mm (approx.)." This is an extremely low vapor pressure. In other words, this chemical produces almost no vapor. What this means is that the potential for tires to affect indoor air quality will be severely limited by the extremely low vapor pressure of the source chemical.
The letter also states, "We do not need these products leaching into our water systems." In order for a tire to affect water quality, it must come into contact with water, and release chemicals into the water. In a properly designed and constructed Earthship, there will be no flux of water through the wall. Therefore, no water will contact the tire. In the unlikely event that water should contact the tire, the water will not become contaminated because carbon black is insoluble in water (NIOSH Pocket Guide).
Jami McBride wrote:(2) And it is not possible to raise even half your food in a 'house's greenhouse. Some of the points are covered in Paul's article on greenhouse suck factor. The biggest problem is the amount of constant carbon dioxide (fresh air for plants). A large volume of plants means air, moisture and light management - the more you grow the more you have to manage. People have asked 'how green is this' when one is spending lots of time and resources to grow plants in an artificial environment. Basically it boils down to, you can only realistically grow a small percent of your total food needs in a greenhouse attached to your house. And after saying all this I still plan on having a greenhouse on my house for passive solar gain but growing plants will be the least of what it will do for me.
I'm not saying Earthships are bad, or that people shouldn't consider them as a choice, just that a deeper look may be warranted.
velacreations Hatfield wrote:why would anyone want to pound 2,000 tires? That's a lot of work, and thank goodness they aren't paying for labor...
We use a modification of Oehler's PSP method. Earthbags could work, too.