permaculture

[YankeePerm@aol.com]

In a message dated 11/9/97 2:41:03 PM, erba@lincolnu.edu wrote:

>The web page (if you want to find it do a search on solar strawbale
>greenhouse) to which I referred has a description of how the
>straw bale greenhouse used earth tubes to preheat or precool air depending
>on the season which also dehumidified the air.  It also has an eloquent
>peice on how the use of solar greenhouses will allow people to grow their
>own food and reduce the impact on the earth from all the transportation
>currently used to transport food. I would be interested to see the design
>plans for this greenhouse.  Also, in reading the book "The Strawbale
>House" I have learned that you can use a variety of plasters to put over
>the bales, creating the surface of the walls, probably even concrete which
>could be water proofed, thus reducing or eliminating the concern about
>humidity causing the bales to decompose.  If anyone is interested in
>strawbale construction get a copy of "The Strawbale House"  it has the
>answers. 
>
>Once again Dan H. Thanks for all the info on using rabbits/animals in 
>greenhouses.

No problem, I need to be reminded I know about this stuff as I get older.

I still recommend skepticism about the durability of strawbale as a
greenhouse wall.  Bear in mind that we are talking mainly about endwalls with
a span, normally, of about 12 feet often tapering to nothing, depending on
the design of the greenhouse, which SHOULD be dictated by climate,
availability of reflective surfaces on the ground, etc.

Now I have to be a party pooper again.  All practical, applied experience I
have heard about with subterranean air intake tubes has been dissapointing to
horrifying.  Dissapointing because the tubes don't really temper the air all
that much and horrifying because, where there are large temperature
differences with the house warmer than the soil, the dehumidification
mentioned leaves moisture in the tubes (That's where it goes) as condensate.
 Besides dumping large amounts of heat in phase change, which of course
negates some of the effectiveness of the cooling, the moisture often, if not
invariabily, promotes growth of molds that sooner or later cast spores that
have very bad effects on human health.  The only practical and lasting
remedy, other than digging a number of 6x6x3 foot holes equaling the
population of the building, is to plug the tubes that you installed at great
expense and difficulty.

This system is not alone in this difficulty.  There are otherwise very, very
efficient rock thermal mass storages, where air circulates through the north
wall (Northern hemisphere) which is filled with rocks of about the same
size*, then travels in the same sort of tubes discussed above back into the
greenhouse.  This is phenomenal for buffering cloudy spells.  Alas, it is
also a phenomenal place for those awful molds to grow.

In case this seems trivial to you, be aware that mold spores can really,
really make you sick.  You don't drop dead, you just languish and grow
weaker.  Anyone who has experienced or witnessed chronic candida can attest
to the evil effects.  If you start with a superhuman immune system, it just
takes longer.  Don't find this one out for yourself.  In addition to a
devastated immune system, general decline in the functioning of a number of
organs can happen.  

OK, it would seem as though the mold problem were soluble, but this is a
place where we want to have research grants, build laboratories, and gather
10 years experience before subjecting humans to living in these conditions.
 I shudder to think how many people out there with languishing health are
thinking, at least my solar home works, no realizing that it is the cause or
a major contributor.  We must all be aware by now that immune disorders are
epidemic, apparently due to the stress of toxins, lack of security, and poor
diet of modern life, as well as emotional distress.  I'll let someone else
rant on that.  I'll only say that I thought my wife was dying (probably was)
of apparently intangible cause untill we found someone who understood that it
was immune collapse due to chronic candida, a common disease immune weakened
people.  Knowing what to do, it takes years to recover to the point of a
reasonably normal life.

Regarding vapor barriers, yes, they should be on the warm side of the wall
which is on the interior in climates where the heating load is greater than
the cooling load.  It appears best to leave the vapor barrier out of walls
between the attached greenhouse and the building to which it is affixed.  I
suggest that you re-read that sentence, it is important.  The other thing to
remember is that it seems virtually impossible to create a complete, 100
percent effective vapor barrier, if the actual research done is any
indicator.  So to a great extent it is a vapor channeler, with concentrations
of condensate where the barrier leaks.  Naturally, in time vapor barriers
will spring more leaks.  Murphy is everywhere.  

The insullation I recommend in cold-winter North country areas is sawdust
mixed about 20:1 with masonry lime.  The lime eliminates insects and rodents,
again probably not 100%.  (100% is probably a conceptual fiction when applied
to processes and large populations.)  The sawdust is a fairly good insulator
even when wet, and the lime keeps it from rotting until it can  dry.
 Cordwood construction (stackwall) with the dawdust/lime fill is a good
greenhouse wall in these situations.  Probably you want to stucco interior
and exterior walls to counter air leaks ("infiltration" is how they say air
leaks in the books).  If you do a good job, air leaks are almost invariably
caused by checking of the cordwood and nothing else.  There are techniques
for eliminating this, or at least reducing it.  Since walls are most likely
to check in summer when it is not so important, you can take your chances and
see if your wall needs stucco by August or so.  This means that you can set
up your greenhouse that much sooner, bearing in mind that maybe you need to
be able to get at those walls.  

Straw bale is a great addition to the permaculture tool box and has many,
many appropriate applications, particularly where people grow grain in
quantity anyway.  In the north woods, it can be questionable for a number of
reasons.  I am reminded of people taking a short workshop in the southwest
who went about putting in swales indiscriminately just tearing up the earth
because swales are a good thing.  I saw one design in which the "swales" were
certain to promote erosion.  Every tool that sometimes works is a good one.
 We need to take the trouble to find out when each is appropriate and not
promote any technique indiscriminately, not even mulching.  Proper
permaculture involves knowing a lot of things and being a good designer.  The
earlier one is in the process of gaining that knowledge and skill, the more
conservative s/he must be to avoid doing harm. At the beginning of the
permaculture movement, Bill promoted beginners finding some working
arrangement with experienced designers.  Nothing ever came of that, so far as
I know.  But it is still the only proposal I have heard of that will spare us
a lot of trashing about doing more harm than good by using useful techniques
in inappropriate ways or circumstances.

For Mother Earth, Dan Hemenway, Yankee Permaculture Publications (since
1982), Elfin Permaculture workshops, lectures, Permaculture Design Courses,
consulting and permaculture designs (since 1981), and now correspondence
courses via email.  Next live training:  Paraguay, Sept. 1998. Internships
available. Copyright, 1997, Dan & Cynthia Hemenway, P.O. Box 52, Sparr FL
32192 USA  YankeePerm@aol.com  

We don't have time to rush.