re: rammed earth: earthships! SOLAR.KnowledgePublications.com

re: rammed earth: earthships!
10 may 1997
willie schmit, crl <"info"@anchor-new mexico.com> wrote:
 
>nick is a proponant of the "light and tight" school of thought.

i've been realizing lately that a solar closet house needs lots of thermal
mass too, so it can keep itself warm on an average winter day (and night),
with an average amount of sun, without using its cloudy day storage.

i've been helping design a solar house in utica, ny, which will likely end up
as a 28x40' 2-story house sloping up to a 40' wide x 24' high south wall
full of windows, as part of an 8' low-thermal-mass sunspace, with a central
solar closet made of masonry with insulation outside it, 20' high and 12' wide
by 8' deep, in the sunspace, containing about 90 drums full of water stacked
6 high (on 6 2x6 shelves) by 5 wide by 3 deep.

the floorslab will contain 4" pvc pipes on 1' centers, running ns, with
sunspace air circulating through them, using a couple of large, low-speed
blowers. this design needs lots of internal thermal mass to work well, in
the sense that if the closet has to supply heat for the house on a 24 hour
average december day (cold and cloudy, with about 600 btu/ft^2 of sun on a
south wall and 27 f in utica), it needs lots of glazing and airflow and
thermal mass surface. if not, it can have a lot less of all that, and be a
"trickle charged heat battery," only discharged on cloudy days. hence the 
slab. this house needs about 250k btu to stay warm on an average day, about
200k of that at night, and the floorslab will have about 10k btu/f, so the
dusk-dawn temp swing might be 20 f. (steve baer says "superinsulation is
fine for heating, but for cooling, you need thermal mass.")

>i am a mass nut - but realize that it has more appeal locally than it would
>elsewhere.  for instance my building site... has over 6000 degree days of 
>heating per year. this figure isn't far off of what it was when i lived 
>in chicago. locally the most important factor is temperature swing.  mass 
>walls - insulated outside can be used as a thermal flywheel to take the 
>peaks off of temperature swings that average 40 degrees a day.  this is a 
>benefit in both summer and winter - with proper overhang pasive solar (or 
>hybrid solar) can contribute to 100% self-sufficiency.

this utica house will have a thermally-isolated sunspace, which may be
vented in summer with shadecloth over the outside to keep it cool.

>...best to listen with one ear- to people that "have done it this way for
>years" to know what is appropriate for the site - then listen to thermal
>engineers (like nick) to bring your ideas into the 21st century!

hey, thanks for the promotion! :-) i'm an ee by training, and most of this
stuff seems like ohm's law to me. newton invented his "law of cooling" a
long time before ohm applied it to electricity, so it seems to me we are
just getting into the 18th century :-) 

nick

nicholson l. pine                      system design and consulting
pine associates, ltd.                                (610) 489-0545 
821 collegeville road                           fax: (610) 489-7057
collegeville, pa 19426                     email: nick@ece.vill.edu

computer simulation and modeling. high performance, low cost, solar heating and
cogeneration system design. bsee, msee. senior member, ieee. registered us
patent agent. solar closet paper: http://leia.ursinus.edu/~physics/solar.html
web site: http://www.ece.vill.edu/~nick 

ps: willie, do you have an email address that works?