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GSBN: Digest for 5/18/07



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---------------------------------------------------------------------


-> Re Thermal Properties of Straw Bale Walls
     by john@...
-> Re: Re Thermal Properties of Straw Bale Walls
     by john@...
-> RE: GSBN:Re Thermal Properties of Straw Bale Walls
     by stoneandstraw@...
-> Re: GSBN:Re Thermal Properties of Straw Bale Walls
     by Martin Hammer mfhammer@...
-> Re: GSBN:A french cousin of "Small SB" is born
     by MattsMyhrman@...
-> Re: GSBN:Re Thermal Properties of Straw Bale Walls
     by Andrew Webb design@...
-> Re: GSBN:Re Thermal Properties of Straw Bale Walls
     by stoneandstraw@...
-> Re: GSBN:Re Thermal Properties of Straw Bale Walls
     by john@...
-> SV: GSBN:Re Thermal Properties of Straw Bale Walls
     by "Jorgen_Munch-Andersen" jma@...
-> Clay/ Earth: Multilingual Terminology Glossary
     by "Dirk Scharmer- FASBA" ds@...
-> Re: GSBN:Re Thermal Properties of Straw Bale Walls
     by jswearingen@...
-> Re: GSBN:Re Thermal Properties of Straw Bale Walls
     by stoneandstraw@...
-> Re: GSBN:Re Thermal Properties of Straw Bale Walls
     by Rene Dalmeijer rene.dalmeijer@...


----------------------------------------------------------------------

Date: 17 May 2007 14:49:47 -0500
From: john@...
Subject: Re Thermal Properties of Straw Bale Walls

G ' day Balers

Can any of you help with thermal properties of jumbo bales?

I have Nehmiah Stone's work and was wondering if I can extrapulate
from them inch by inch?

If so what value would you give a 900mm or 36" straw bale wall plus
100mm or 4" of render?

We are about to build a community centre in Sydney for the Fairfield
City Council from jumbo balaes 2.4m x 900mm x 600mm.   Bales 6 high or
a wall of 3.8 m finished including top and bottom plates.  The
building will be used for community events in the heart of Sydney or
it's geographical centre.  Will be good for straw bale. Bales on the
flat i.e. 900mm.

Any help will be appreciated thanks.

Aussie R values are around R7-9 for straw bales so multiply by 5.6 for
USA R values, I think.

Kind regards
John Glassford
Huff 'n' Puff Constructions
<a  target="_blank" href="http://www.glassford.com.au/";>http://www.glassford.com.au/</a>
Mount Kilimanjaro Climb 28/8/07
<a  target="_blank" href="http://www.coolamonrotary.com/kili/";>http://www.coolamonrotary.com/kili/</a>
61 2 6927 6027

Yours in Rotary
John Glassford
International Services Director
Rotary Club of Coolamon District 9700
New South Wales, Australia
Mount Kilimanjaro Climb 28/8/07
<a  target="_blank" href="http://www.coolamonrotary.com/kili/";>http://www.coolamonrotary.com/kili/</a>
Road MAPS to Africa Web Site:
<a  target="_blank" href="http://www.coolamonrotary.com/maps/";>http://www.coolamonrotary.com/maps/</a>
Chair RFFA (Australia): Rotarians Action Group Fighting AIDS.
<a  target="_blank" href="http://rffa.org/";>http://rffa.org/</a>
61 2 6927 6027


----------------------------------------------------------------------

Date: 17 May 2007 14:51:01 -0500
From: john@...
Subject: Re: Re Thermal Properties of Straw Bale Walls

Apologies for double senders address it is early here and it has been
raining all night, you beauty!

El Lupo


----------------------------------------------------------------------

Date: 17 May 2007 17:08:09 -0500
From: stoneandstraw@...
Subject: RE: GSBN:Re Thermal Properties of Straw Bale Walls

John,

For all intents and purposes, the value per inch is constant once you get
to the size of a bale.  It might not be if you were dramatically
down-sizing from the test specimens, but going larger, relative uniformity
is a safe assumption.  What we found in the ORNL test was about 1.47 per
inch (3.82/m Aussie).  Since the render adds mass w/o any significant
insulation, the 36" bale wall you are considering should be about R-53
(~R-9.4 Aussie).
Hope this helps.

Nehemiah Stone
stoneandstraw@...



> [Original Message]
> From: John Glassford jacksflat@...
> To: GSBN GSBN@...
> Date: 5/17/2007 1:40:33 PM
> Subject: GSBN:Re Thermal Properties of Straw Bale Walls
>
> G ' day Balers
>
> Can any of you help with thermal properties of jumbo bales?
>
> I have Nehmiah Stone's work and was wondering if I can extrapulate
> from them inch by inch?
>
> If so what value would you give a 900mm or 36" straw bale wall plus
> 100mm or 4" of render?
>
> We are about to build a community centre in Sydney for the Fairfield
> City Council from jumbo balaes 2.4m x 900mm x 600mm.   Bales 6 high or
> a wall of 3.8 m finished including top and bottom plates.  The
> building will be used for community events in the heart of Sydney or
> it's geographical centre.  Will be good for straw bale. Bales on the
> flat i.e. 900mm.
>
> Any help will be appreciated thanks.
>
> Aussie R values are around R7-9 for straw bales so multiply by 5.6 for
> USA R values, I think.
>
> Kind regards
> John Glassford
> Huff 'n' Puff Constructions
> <a  target="_blank" href="http://www.glassford.com.au/";>http://www.glassford.com.au/</a>
> Mount Kilimanjaro Climb 28/8/07
> <a  target="_blank" href="http://www.coolamonrotary.com/kili/";>http://www.coolamonrotary.com/kili/</a>
> 61 2 6927 6027
>
> Yours in Rotary
> John Glassford
> International Services Director
> Rotary Club of Coolamon District 9700
> New South Wales, Australia
> Mount Kilimanjaro Climb 28/8/07
> <a  target="_blank" href="http://www.coolamonrotary.com/kili/";>http://www.coolamonrotary.com/kili/</a>
> Road MAPS to Africa Web Site:
> <a  target="_blank" href="http://www.coolamonrotary.com/maps/";>http://www.coolamonrotary.com/maps/</a>
> Chair RFFA (Australia): Rotarians Action Group Fighting AIDS.
> <a  target="_blank" href="http://rffa.org/";>http://rffa.org/</a>
> 61 2 6927 6027

>




----------------------------------------------------------------------

Date: 17 May 2007 17:48:20 -0500
From: Martin Hammer mfhammer@...
Subject: Re: GSBN:Re Thermal Properties of Straw Bale Walls

Hello Nehemiah,

Is there not a different R-value per inch for bales on-edge and laid-flat?
My understanding is that the Oak Ridge National Lab test showed this.  The
result, in California, being that walls with 3-string bales on-edge (15"
thick) and laid-flat (23" thick) are considered by the California Energy
Commission to have the same R-value of R-30.  If I am correct that would
yield an R-value per inch as follows:

On-edge:  R-2 per inch
Laid-flat:  R-1.3 per inch

I know there has been discussion about straw orientation, which in theory
explains the higher unit R-value for a bale on-edge, and how not all baling
machines bale straw with a clear orientation.  (I can tell you that the
straw orientation of the bales we're making manually in Pakistan have no
orientation.  We just grab big balls of straw and stuff them into the
compression mold!)

I also wonder if there is any appreciable difference from one grain to
another.

Any sage thoughts?

Martin Hammer



> John,
>
> For all intents and purposes, the value per inch is constant once you get
> to the size of a bale.  It might not be if you were dramatically
> down-sizing from the test specimens, but going larger, relative uniformity
> is a safe assumption.  What we found in the ORNL test was about 1.47 per
> inch (3.82/m Aussie).  Since the render adds mass w/o any significant
> insulation, the 36" bale wall you are considering should be about R-53
> (~R-9.4 Aussie).
> Hope this helps.
>
> Nehemiah Stone
> stoneandstraw@...
>
>
>
>> [Original Message]
>> From: John Glassford jacksflat@...
>> To: GSBN GSBN@...
>> Date: 5/17/2007 1:40:33 PM
>> Subject: GSBN:Re Thermal Properties of Straw Bale Walls
>>
>> G ' day Balers
>>
>> Can any of you help with thermal properties of jumbo bales?
>>
>> I have Nehmiah Stone's work and was wondering if I can extrapulate
>> from them inch by inch?
>>
>> If so what value would you give a 900mm or 36" straw bale wall plus
>> 100mm or 4" of render?
>>
>> We are about to build a community centre in Sydney for the Fairfield
>> City Council from jumbo balaes 2.4m x 900mm x 600mm.   Bales 6 high or
>> a wall of 3.8 m finished including top and bottom plates.  The
>> building will be used for community events in the heart of Sydney or
>> it's geographical centre.  Will be good for straw bale. Bales on the
>> flat i.e. 900mm.
>>
>> Any help will be appreciated thanks.
>>
>> Aussie R values are around R7-9 for straw bales so multiply by 5.6 for
>> USA R values, I think.
>>
>> Kind regards
>> John Glassford
>> Huff 'n' Puff Constructions
>> <a  target="_blank" href="http://www.glassford.com.au/";>http://www.glassford.com.au/</a>
>> Mount Kilimanjaro Climb 28/8/07
>> <a  target="_blank" href="http://www.coolamonrotary.com/kili/";>http://www.coolamonrotary.com/kili/</a>
>> 61 2 6927 6027
>>
>> Yours in Rotary
>> John Glassford
>> International Services Director
>> Rotary Club of Coolamon District 9700
>> New South Wales, Australia
>> Mount Kilimanjaro Climb 28/8/07
>> <a  target="_blank" href="http://www.coolamonrotary.com/kili/";>http://www.coolamonrotary.com/kili/</a>
>> Road MAPS to Africa Web Site:
>> <a  target="_blank" href="http://www.coolamonrotary.com/maps/";>http://www.coolamonrotary.com/maps/</a>
>> Chair RFFA (Australia): Rotarians Action Group Fighting AIDS.
>> <a  target="_blank" href="http://rffa.org/";>http://rffa.org/</a>
>> 61 2 6927 6027
>> ----
>> For instructions on joining, leaving, or otherwise using the GSBN list,
> send email to GSBN@...HELP in the SUBJECT line.
>> ----
>>
>
>
> ----
> For instructions on joining, leaving, or otherwise using the GSBN list, send
> email to GSBN@...HELP in the SUBJECT line.
> ----
>




----------------------------------------------------------------------

Date: 17 May 2007 17:52:51 -0500
From: MattsMyhrman@...
Subject: Re: GSBN:A french cousin of "Small SB" is born

I second the kudos, huzzahs and pats on the backs for Andre.  Getting good
stuff on strawbale out in many a "lingua franca" is important support for the
expansion of the method.  What's next, Gaelic?



**************************************
 See what's free at .


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Date: 17 May 2007 17:54:00 -0500
From: Andrew Webb design@...
Subject: Re: GSBN:Re Thermal Properties of Straw Bale Walls

For what it's worth, BERS Pro, the energy-rating software, gives a value
of R5.25 for a 520 thick rendered bale wall and R9.80 for a 970 thick
wall (allowed 35mm render both sides).

- -AW



>> [Original Message]
>> From: John Glassford jacksflat@...
>> To: GSBN GSBN@...
>> Date: 5/17/2007 1:40:33 PM
>> Subject: GSBN:Re Thermal Properties of Straw Bale Walls
>>
>> G ' day Balers
>>
>> Can any of you help with thermal properties of jumbo bales?...
>



----------------------------------------------------------------------

Date: 17 May 2007 18:12:48 -0500
From: stoneandstraw@...
Subject: Re: GSBN:Re Thermal Properties of Straw Bale Walls

The test we did in California had one wall laid flat and one on edge.  And
yes, we got the same total value for the wall both orientations, meaning
that the R/inch for bales on edge is higher than for bales laid flat.
However, we only got about R-0.9/inch both ways due to serious issues with
the top few inches of the walls, inadequate drying (curing) time, and other
anomalies.  The ORNL test was only with bales laid flat.  I don't suggest
putting too much stock in the on-edge/laid-flat difference we "found" in
CA.  ...at least not until someone repeats the experiment with better QC.
BTW, the R/inch for the on-edge bale wall in CA was about R-1.3/inch.
Since no such test was done at ORNL, THAT is the value that someone should
use if they feel a need to have a separate one for "cross orientation."

Nehemiah Stone
stoneandstraw@...



> [Original Message]
> From: Martin Hammer mfhammer@...
> To: GSBN GSBN@...
> Date: 5/17/2007 4:40:23 PM
> Subject: Re: GSBN:Re Thermal Properties of Straw Bale Walls
>
> Hello Nehemiah,
>
> Is there not a different R-value per inch for bales on-edge and laid-flat?
> My understanding is that the Oak Ridge National Lab test showed this.  The
> result, in California, being that walls with 3-string bales on-edge (15"
> thick) and laid-flat (23" thick) are considered by the California Energy
> Commission to have the same R-value of R-30.  If I am correct that would
> yield an R-value per inch as follows:
>
> On-edge:  R-2 per inch
> Laid-flat:  R-1.3 per inch
>
> I know there has been discussion about straw orientation, which in theory
> explains the higher unit R-value for a bale on-edge, and how not all
baling
> machines bale straw with a clear orientation.  (I can tell you that the
> straw orientation of the bales we're making manually in Pakistan have no
> orientation.  We just grab big balls of straw and stuff them into the
> compression mold!)
>
> I also wonder if there is any appreciable difference from one grain to
> another.
>
> Any sage thoughts?
>
> Martin Hammer
>
>
>
> > John,
> >
> > For all intents and purposes, the value per inch is constant once you
get
> > to the size of a bale.  It might not be if you were dramatically
> > down-sizing from the test specimens, but going larger, relative
uniformity
> > is a safe assumption.  What we found in the ORNL test was about 1.47 per
> > inch (3.82/m Aussie).  Since the render adds mass w/o any significant
> > insulation, the 36" bale wall you are considering should be about R-53
> > (~R-9.4 Aussie).
> > Hope this helps.
> >
> > Nehemiah Stone
> > stoneandstraw@...
> >
> >
> >
> >> [Original Message]
> >> From: John Glassford jacksflat@...
> >> To: GSBN GSBN@...
> >> Date: 5/17/2007 1:40:33 PM
> >> Subject: GSBN:Re Thermal Properties of Straw Bale Walls
> >>
> >> G ' day Balers
> >>
> >> Can any of you help with thermal properties of jumbo bales?
> >>
> >> I have Nehmiah Stone's work and was wondering if I can extrapulate
> >> from them inch by inch?
> >>
> >> If so what value would you give a 900mm or 36" straw bale wall plus
> >> 100mm or 4" of render?
> >>
> >> We are about to build a community centre in Sydney for the Fairfield
> >> City Council from jumbo balaes 2.4m x 900mm x 600mm.   Bales 6 high or
> >> a wall of 3.8 m finished including top and bottom plates.  The
> >> building will be used for community events in the heart of Sydney or
> >> it's geographical centre.  Will be good for straw bale. Bales on the
> >> flat i.e. 900mm.
> >>
> >> Any help will be appreciated thanks.
> >>
> >> Aussie R values are around R7-9 for straw bales so multiply by 5.6 for
> >> USA R values, I think.
> >>
> >> Kind regards
> >> John Glassford
> >> Huff 'n' Puff Constructions
> >> <a  target="_blank" href="http://www.glassford.com.au/";>http://www.glassford.com.au/</a>
> >> Mount Kilimanjaro Climb 28/8/07
> >> <a  target="_blank" href="http://www.coolamonrotary.com/kili/";>http://www.coolamonrotary.com/kili/</a>
> >> 61 2 6927 6027
> >>
> >> Yours in Rotary
> >> John Glassford
> >> International Services Director
> >> Rotary Club of Coolamon District 9700
> >> New South Wales, Australia
> >> Mount Kilimanjaro Climb 28/8/07
> >> <a  target="_blank" href="http://www.coolamonrotary.com/kili/";>http://www.coolamonrotary.com/kili/</a>
> >> Road MAPS to Africa Web Site:
> >> <a  target="_blank" href="http://www.coolamonrotary.com/maps/";>http://www.coolamonrotary.com/maps/</a>
> >> Chair RFFA (Australia): Rotarians Action Group Fighting AIDS.
> >> <a  target="_blank" href="http://rffa.org/";>http://rffa.org/</a>
> >> 61 2 6927 6027
> >> ----
> >> For instructions on joining, leaving, or otherwise using the GSBN list,
> > send email to GSBN@...HELP in the SUBJECT line.
> >> ----
> >>
> >
> >
> > ----
> > For instructions on joining, leaving, or otherwise using the GSBN list,
send
> > email to GSBN@...HELP in the SUBJECT line.
> > ----
> >
>
>

>




----------------------------------------------------------------------

Date: 17 May 2007 20:19:09 -0500
From: john@...
Subject: Re: GSBN:Re Thermal Properties of Straw Bale Walls

G ' day Nehemiah and Andrew et al

Many thanks for the replies and for your considered input.  It is very
much appreciated.

I am sure that there is much more work to be done in this area
especially with jumbo bales as they are naturally compacted a lot more
than the smaller bales.  Does that provide more or less insulation?
Many questions ahead of  us.

Kind regards John Glassford.


----------------------------------------------------------------------

Date: 18 May 2007 22:39:44 -0500
From: "Jorgen_Munch-Andersen" jma@...
Subject: SV: GSBN:Re Thermal Properties of Straw Bale Walls

Dear all
 
A summary of different measurements of heat conductivity and U-values (in
SI-units, note also that U-values are the inverse of R-values) are given in
English at pp 43 - 45 in our publication on SB-houses. It can be downloaded
from 
<a  target="_blank" href="http://www.sbi.dk/byggeteknik/konstruktioner/serlige-konstruktioner/halmhuse/halmhuse";>http://www.sbi.dk/byggeteknik/konstruktioner/serlige-konstruktioner/halmhuse/halmhuse</a>
 
There is an optimal density for every material, but it will vary with the type
of straw. The optimum is very flat for most materials, and it surely is flat
for straw. There are much bigger problems than the influence of the density to
be solved if we want reliable U-values. This is also dealt with in our
publication.
 
Best wishes 
 
Jorgen Munch-Andersen
SBi (Danish Building Research Institute)
Dr Neergaardsvej 15
DK-2970 Horsholm
Tel +45 4574 2388 (dir)
Fax +45 4586 7535
jma@...

________________________________

Fra: GSBN pa vegne af John Glassford
Sendt: fr 18-05-2007 04:03
Til: GSBN
Emne: Re: GSBN:Re Thermal Properties of Straw Bale Walls



G ' day Nehemiah and Andrew et al

Many thanks for the replies and for your considered input.  It is very
much appreciated.

I am sure that there is much more work to be done in this area
especially with jumbo bales as they are naturally compacted a lot more
than the smaller bales.  Does that provide more or less insulation?
Many questions ahead of  us.

Kind regards John Glassford.
- ----
For instructions on joining, leaving, or otherwise using the GSBN list, send
email to GSBN@...HELP in the SUBJECT line. 
- ----





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Date: 18 May 2007 22:40:46 -0500
From: "Dirk Scharmer- FASBA" ds@...
Subject: Clay/ Earth: Multilingual Terminology Glossary

Maybe this is interesting for someone:

A Multilingual Terminology Glossary for Clay/ Earth construction for
translation from/ into english, french, spain, russian, german on
<a  target="_blank" href="http://www.dachverband-lehm.de/de/05_wissen/05-4_wissen_glossar.htm#";>http://www.dachverband-lehm.de/de/05_wissen/05-4_wissen_glossar.htm#</a>

Dirk Scharmer

- -----------------------------------------------
Fachverband Strohballenbau Deutschland e.V.
Auf der Ruebekuhle 10
D- 21335 Lueneburg
Tel. 00 49 4131- 2278649
Fax. 00 49 4131- 2278648
Internet: www.fasba.de
Email: ds@...



----------------------------------------------------------------------

Date: 18 May 2007 22:41:21 -0500
From: jswearingen@...
Subject: Re: GSBN:Re Thermal Properties of Straw Bale Walls

That's an interesting question.  I would think that more compression is
better, until the straw fibers are being crushed, because it results in
smaller air spaces for convection.

As to bales flat or on edge, I think since you are hanging by your feet at
the bottom of the globe, and summer is winter and winter is summer and you
point your houses north for solar gain, it stands to reason that your bales
should be on edge....

John "Up Over from Down Under" Swearingen


On 5/17/07, John Glassford jacksflat@... wrote:
>
> G ' day Nehemiah and Andrew et al
>
> Many thanks for the replies and for your considered input.  It is very
> much appreciated.
>
> I am sure that there is much more work to be done in this area
> especially with jumbo bales as they are naturally compacted a lot more
> than the smaller bales.  Does that provide more or less insulation?
> Many questions ahead of  us.
>
> Kind regards John Glassford.

>



- --
John Swearingen
Skillful Means, Inc.
Design and Construction
www.skillful-means.com


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Date: 18 May 2007 22:41:47 -0500
From: stoneandstraw@...
Subject: Re: GSBN:Re Thermal Properties of Straw Bale Walls

John,

I did not see a response from Andrew.  Was that off list?  I am always
interested in what new or other information people have on the thermal
properties of straw bale construction.  Care to share his input?
Also, your Q about how compaction affects R-value is a potent question.  If
hot box testing wasn't so expensive and time consuming, or if there were
funders lined up to pay for it, I'd already have an answer for you.  There
are a number of confounding factors, so until someone has done the actual
research, we can throw around lots of theories.
For example, it is air that creates the insulation value of almost
everything used for wall insulation.  ,,,not the spun glass, not the solid
portions of the foam, not the cellulose, not the straw.   Therefore, if
bales are compacted too much, one would expect the insulation value to go
down.  But, what is "too much?"  If bales are too loose, then the air can
circulate in the air pockets and research HAS shown that this can lead to
convective currents that lead in turn, to a dramatic drop in R-value.  That
was one of the causes (we think) for the relatively low R-values in the ATI
lab tests in Fresno, CA.  Once we stacked the bales in the hot box wall
opening, and compressed them as they'd be in a building wall, we had a six
inch gap at the top.  We filled it with straw as tightly as we could, but
we are not match for either a baler or truckers' strap tightening levers,
so we KNOW that the top (where the greatest amount of heat exchange would
naturally occur anyway) was much looser than the rest of the wall.  Ditto
the sides, though those gaps were significantly smaller (so perhaps, harder
to compact straw into).
Further, though in theory greater compaction - after the optimal point -
will lead to a decreasing R-value, no tests have yet shown that to be the
case.  Perhaps we just haven't found the optimal compression force yet.
Perhaps the theory is wrong.
Lastly, I would question your assertion that jumbo bales are "naturally
compacted a lot more than the smaller bales."  It is mechanically more
difficult to compact a larger bale to the same density as a smaller one.  I
am not saying that the machinery isn't designed to do so - perhaps it is.
But, from a pure physics point of view, it is not "natural" as you said.
One way to verify whether the compaction is greater or not is to measure
the water content and density.  Rice straw bales in California (the ones we
tested) are typically at least 8 pounds per cubic foot at a moisture
content of about 6%.  Do you have similar data on the Aussie jumbo bales?
If you want to get an accurate reading of the moisture content (more
accurate than a moisture meter stuck a random depth into the bales), let me
know and I will send you (offline) a description of how we did it.  The
density (#/cf or kG/cM) is pretty easy, assuming you can weigh a
representative sample of the bales.
Hope this helps.
Thanks,

Nehemiah Stone
stoneandstraw@...



> [Original Message]
> From: John Glassford jacksflat@...
> To: GSBN GSBN@...
> Date: 5/17/2007 7:18:59 PM
> Subject: Re: GSBN:Re Thermal Properties of Straw Bale Walls
>
> G ' day Nehemiah and Andrew et al
>
> Many thanks for the replies and for your considered input.  It is very
> much appreciated.
>
> I am sure that there is much more work to be done in this area
> especially with jumbo bales as they are naturally compacted a lot more
> than the smaller bales.  Does that provide more or less insulation?
> Many questions ahead of  us.
>
> Kind regards John Glassford.

>




----------------------------------------------------------------------

Date: 18 May 2007 22:41:55 -0500
From: Rene Dalmeijer rene.dalmeijer@...
Subject: Re: GSBN:Re Thermal Properties of Straw Bale Walls

John,

You could simply use my java script SB R-value calculator. (
<a  target="_blank" href="http://www.strobouw.nl/technical/sbrvalue.html";>http://www.strobouw.nl/technical/sbrvalue.html</a> this is the deep link
directly to the page, thus avoiding many clicks.)
It is primed with a not too conservative labda value of 0.08 but you
can insert your own favorite value. The calculator also gives some
notes on SB r-values. The calculator works both ways ie you can
determine how thick a SB wall should be to achieve a certain R-value or
given a certain thickness what the r-Value would be. It also takes an
interior and exterior earth plaster into account including the interior
and exterior air transition. In metric and imperial. You can also use
the calculator as a metric to imperial R value converter.

The R value of a SB wall is something of a holy grail for the SB
community it is difficult to give really hard values for. What we do
know is that taking good SB practice into account a labda value of 0.1
is rather pessimistic and 0.045 is very optimistic. Based on previous
discussions I expect that air convection within jumbo bales is even
more of an issue then normal 2-3 string bales this will be offset
though by the higher density of the jumbo bales.

Rene
On May 18, 2007, at 04:03, John Glassford wrote:

> G ' day Nehemiah and Andrew et al
>
> Many thanks for the replies and for your considered input.  It is very
> much appreciated.
>
> I am sure that there is much more work to be done in this area
> especially with jumbo bales as they are naturally compacted a lot more
> than the smaller bales.  Does that provide more or less insulation?
> Many questions ahead of  us.
>
> Kind regards John Glassford.
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> list, send email to GSBN@...HELP in the
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