From: Dirk Scharmer- Architekturb?ro WAND4 <info@wand4...>
Herbert, Andr?, Peter, ...
I sent our last test results directly to Andr?. Herbert, I think you
know the Austrian activities very well but let me speak for the German
results and approvals:
In Germany we did about 15 lambda-Value tests (thermal conductivity)
according to EN 12667 since Mai 2003 (Attention! Herbert used
accidentally the term 'R-Value' which is not the conductivity but the
thermal resistance). We found a variety of values mainly depending on
density, humidity and fibre orientation and probably fibre length
(type
of harvester-thresher).
Our best value was lambda 10,dry= 0,038 W/mK and our worst
lambda10,23/80=0,082 W/mK. We found conversion factors from dry to wet
between 1,07 to 1,2.
We tested densities (dry) from 80/ to 116 kg/m3. We tested wheat and
rye.
The official approved "Baustrohballen" can be calculated perpendicular
to the fibre direction with lambda=0,052 W/mK (max. lambda dry=0,044
W/mK+ 20% addition) and in fibre direction with lambda=0,08 W/mK (max.
lambda dry=0,067 W/mK + 20% addition).
Our current goal is not the maximum optimization of the lambda value
but
the maximum optimization of the usability of local bales which are
produced under normal agriculture conditions. For this it is more
important to provide a calculation lambda value which covers the
variety
of occuring lambda values to avoid failing of some bale charges (the
distributor has to sign for the compliance of the properties).
I think we should have a session at the ESBG in Belgium in August to
this topic where we first present the current knowledge and the
country
results to each other. After heaving heard the international results
and
approaches we should of course discuss, e.g. lambda value
optimization,
fibre direction, humidity, density and strategy, ...
And to avoid another confusion: "Baustrohballen" are of course
"normal"
straw bales and I think there is not a difference to normal austrian
bales (of course we saw differences in past between bales from
different
countries depending on the baler, on the acre, on the type of corn, on
the type of cultivation,.... "Baustrohballen" are produced directly on
the fields with normal balers (common ones in Germany: Welger ap 53,63
and 630 to 830, or different types of John Deere or Claas,...)
I'm keen to see the new Austrian test reports and how you managed to
optimize the lambda Value (pressing method?) and how you want to
ensure
the thermal quality while the production of the bales.
And last but not least: Straw is not equal to straw, testing
procedures
not equal to testing procedures and countries approaches not equal
to ...
And please have in Mind: Most of the international R-Value-Tests (now
I'm speaking about the resistance) shows much higher recalculated
lambda-Values >0,06 W/mk as the Germans and Austrians are talking
about,
on more reason for me, not to count on the best values.
Dirk
Fachverband Strohballenbau Deutschland e.V.
c/o Dirk Scharmer
In de Masch 6
D-21394 Suedergellersen
Tel. 0049 4131- 727804
Fax. 0049 4131- 727805
Internet: www.fasba.de
Email: ds@fasba...