Re: Questions about autonomous houses
- To: Derek dot Schatz at predictive dot com
- Subject: Re: Questions about autonomous houses
- From: Patrick Salsbury <salsbury at sculptors dot com>
- Date: Thu, 26 Jul 2001 14:43:44 -0700
- Cc: domesteading at bootstrap dot sculptors dot com
- In-reply-to: Your message of "Thu, 26 Jul 2001 15:40:09 EDT." <OF99974403.91E301EB-ON85256A95.006A149F@predictive.com>
I got the following from a friend who was checking out the website. Wanted to
CC: the Domesteading list, since I think the questions are very good, and
should be thought about by the community.
I've also asked Derek to join the list. :-)
> Hi Patrick-
> I just read through your RS pages - very interesting. Some
> - Your overall design is very well thought out
Thank you. :-) For those who haven't seen them, yet, I just added some
of the most recent renderings yesterday afternoon near the bottom of
These include pictures showing some various wall/window combinations.
> - Aerogels are very cool, but how close are they to manufacturability? For
> some time after that point, I expect that aerogel panels as you describe
> will be quite expensive, especially with a polymer liquid crystal
Yes, I suspect they probably will be quite expensive for a while. From
what I've read, there is a bit of trickiness to manufacturing, but mainly due
to fragility, and the need to use high-pressure CO2 to force
the ethanol out of the aerogel.
The 'gel' is injected as a liquid into a mold, or simply into a pan
or petri dish. It's then allowed to solidify into the silica aerogel matrix,
which is still full of liquid, but now has the sponge-like structure within
it. This can take several days to solidify fully. Then the aerogel is put into
a high-pressure chamber. It uses a CO2 atmosphere at pressures ranging from
750-1050 psi. The high pressure means you don't have to use much heat. In
fact, the whole process can be completed in temperature
ranges from 5-31C (41-88F). This causes the liquid ethanol to
be forced out of the matrix, and it can be drawn off.
There's a detailed description of this process, including recipes and
procedures, here: http://eande.lbl.gov/ECS/aerogels/saprep.htm
If you envision a triangular "pizza box" design made of Lexan or glass,
you'll have the basic idea for a panel as I'm thinking of it. At one corner is
a valve to inject the liquid gel, and at another corner is a valve to release
air/liquid during the process. You inject, let it sit, then remove the ethanol
as noted above. After that, the valves could be permanently sealed, and you've
got a super-insulating panel.
Yes, it will be expensive to start. So were automobiles, and the
tooling necessary to produce the production lines for a new car often range in
the $2-4 Billion range. However, if the first car off the line costs $4
billion, the second is only $2 billion, and by the time you're cranking out
hundreds of thousands, the price drops into an affordable range.
I suspect that part of the reason aerogels aren't widely used yet is
1) It's extremely difficult to make them clear. Thus they aren't widely
used in windows, yet. This will change as soon as they perfect transparent
production. Mark my words. :-)
In my case, I'm not concerned with perfect transparency, and am happy
to get just "pretty transparent" results. In fact, if we don't do LCD
light-shutter panels at the outset (also expensive) then we'll want many
opaque panels. You can make opaque aerogels by 'doping' them with other
materials. Carbon and iron for black, copper for green, iron oxide for orange,
nickel for blue, etc. You can see photos of some of these, and even a magnetic
aerogel (made with iron oxide), here:
2) I don't think there's been a real need/demand for them, yet. I hope
to correct this by creating the demand for millions of panels, so that many
companies begin to compete for this market and develop manufacturing processes
that streamline production.
I've emailed Hubert van Hecke, who's page I reference, and even he, as
an aerogel researcher, doesn't see much demand commercially. So far, they're
mainly a scientific curiosity, and used in esoteric research, such as space
projects. Current housing practices use stone and wood and foam as insulators.
They aren't concerned with weight, nor with transparency. I'm concerned with
both, so I've focused on aerogels, but I realize there are other ways to do
it, and some of those are cheaper (but may not give all the properties I want.)
> - The articulating legs will also be very expensive
Perhaps not. As I posted to Domesteading last year
(http://reality.sculptors.com/~hyprmail/domesteading/1505.html) these things
are already being manufactured for the trucking industry. I don't know the
unit-cost of them, but I suspect it's not a large fraction of the overall
price of the truck. As another list member (Don Bowen) pointed out in a
followup message, hydraulic elevator lifts are another fine example of
existing technology for this component.
> - Despite their advantages, dome homes have not taken off in popularity.
> The vast majority of people are too used to box-shaped houses to even
> consider something so different.
Granted. However, as a counterpoint to this argument, I live in a
dome, and have had hundreds of people visit over the last 3 years. Not a
single one has voiced dismay, disgust, or outright rejection. In fact, almost
uniformly the response has been quite the opposite, with approval, admiration,
and in some cases outright desire to have one for themselves.
> - The main cost component of a home is the land, so your design will only
> become cost-effective in outlying areas where land is cheap. I would
> guess that the "egg" would not be any cheaper to build than a traditional
> structure. Yes, cost will come down with mass production, but IMHO the
> potential market is much, much smaller than you hope for.
We'll see. At first, I'd agree with you. But the idea is to radically
change the housing industry over the long-run. In the beginning, demand for
automobiles was small, and only the rich could afford them. In the beginning,
demand for computers was small, and the head of IBM predicted there'd never be
a need for more than perhaps 12 of their machines, worldwide.
I'm hoping to bring the same technological advantages shown in car and
computer manufacturing to bear on the housing industry.
According to calculations done by Bucky Fuller, a full-scale
manufacturing facility producing houses would be roughly comparable with a
full-scale automobile manufacturing facility. It would cost billions to set
up, but would produce products roughly comparable in price to automobiles.
At first, I'm sure they'll be very expensive. But in time, I suspect
they'll drop to the $25,000-$50,000/unit range. This would put them in the
"MUCH cheaper than ordinary housing" category (at least, in California! ;^) )
and in the "cheaper than ordinary housing" category elsewhere. Coupled with
the 4000+ square foot living area, the self-contained life-support systems,
and the non-reliance on external utilities, it should prove to be a better buy
than traditional housing. At least, that's the hope.
Land prices may well skyrocket once it's as easy to live in the remote
wilderness as it is in a developed area. But with this house, you should be
able to rent land from farmers, or rooftops from building owners in Manhattan
or San Francisco. The house should work anywhere, if built correctly.
Farther out, these will be massively useful for off-world colonists,
moving to the Moon, Mars, or points beyond, where infrastructure doesn't exist.
> - I could see corporations using these for worker housing at remote job
> sites, like northern Alaska, but you won't sell any to an Inuit
True again. I've posted elsewhere on Domesteading about the use for
remote research teams, with laboratory resources, etc. They won't be the
perfect solution for everyone, but they should be another option in the
spectrum of housing for those who want them, regardless of race.
> - For very cold climates, you'll need the panels to provide an R-value of
> at least 25, or extra insulation will be needed. The internal open design
> means you have to heat the entire space, as there's no way to limit it to
> a subsection where the residents are actually living at the moment (like
> closing vents to unused rooms in a traditional home)
Aerogel is R20/inch, and if you evacuate the air from the aerogel
(which would be possible in the panel design I outline above) then it goes up
to R32/inch. Doing a 2" panel would put you into the R40-R64 range, plus any
insulation you get from the glass/Lexan encasing the panel.
I want the house to be versatile, including changeable wall
configurations, and even changing floor configurations. An open design allows
for greater circulation and all-around temperature balance, but the ability to
close off sections is also useful. My recent renderings include separate rooms
on the 2nd floor. I actually envision the house having options to create
spaces on any floor, and even to get rid of the vaulted space, if people want
more floor space. (The vaulted space is nice, but it removes about 1000 sq.
feet from the available floor space, reducing it from about 5200'sq. to about
I feel that the floor plan and wall layout should be options left up
to the owners, and changeable as the family changes, or whatever their desire.
I like to think of the "house as a theater stage". You should be able to
change your set, move around walls, change the lighting, etc. The structure of
the dome means that you don't *require* any internal support walls, but that
doesn't mean you can't have walls.
> Just some stuff off the top of my head - I'd love to hear your thoughts.
> Best regards,
> Derek Schatz, CISSP
> Sr. Consultant
> Predictive Systems,
> Global Integrity Information Security
Excellent questions, all! I'm glad you posted them, and again would
invite you to join the Domesteading list.
Anyone else want to contribute thoughts/questions/answers on this?
___________________Think For Yourself____________________
Patrick G. Salsbury - http://reality.sculptors.com/~salsbury/
Interested in Airships? See http://reality.sculptors.com/lists.html
There is a difference between apathy and withdrawing in disgust.
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