[Strawbale] comparing insulation materials

Herbert Gruber d.sign at aon...
Mon Nov 4 14:46:31 CET 2002

Dear Martin, dear balers
I tried to send this email to the GSBN-list, but I dont know, if I am still
listed, because it came back.
So I do it this way, maybe its interesting for the European list too.

Responding to your idea to compare common building-products (insulation),
here is our calculation based on
* prices from local building-markets
* declarations and tests from insulation-manufacturers
* the values, Holger König (a well known Baubiologist in Germany) describes
in his books (e.g. "Das Dachgeschoß", Ökobuch-Verlag)
* added by the calculations concerning production energy with the help of
Gerd Zwieners book "Ökologisches Baustoff-Lexikon" (C.F.Müller).

(European) terms: 
You know: Lambda L= W/mK describes the amount of warmth going through a 1m
thick material in 1 second per squaremeter, when the temp-difference is 1°K
(=1°C); the lower L is, the better the insulation-capacity. L depends and
differs with the amount of waterdamp, which is in the material, so each
organic material has to have a 20% addiction to
LRTr10 (new after CEN = LNTr10): insulation value (Lambda) for a dry (tr)
material at a temperature of 10°C (for 1m, so L never depends on thickness
of wall)
k-value (new after CEN: U-value): k= W/m2K (Wärmedurchgangskoeffizient, dont
know the english word), depends on the thickness of the wall
PEI: amount of energy to manufacture/transport/.. a matarial

1) comparison of values

material        L      LRtr10         raw-weight    included prod-energy
           (W/m2K)                     kg/m3           (PEI: kWh/m3)

strawbales   0,045     0,038            100             5-30
                      (as proved in our official tests in Austria)

cellulose    0,045     0,038            35-70           110-190
(made from 80% newspaper)

EPS-W15      0,038     0,038            15-30           400-1.050
(polystyrol-plates: XPS or EPS)

XPS            0,020-0,035              15-30           400-1.050

fibreglass   0,038     0,038            100             100-500

reed         0,045-55  0,039-45         225             ? (maybe same as SB)
            (depending on the amount of wire to hold it together)

flax-mat     0,045     0,038            150             ? (prob. 30-50)

cork-plates  0,045     0,038            80              ? low, but long
(heat-expanded cork)                                    transport-ways

cocos-mats   0,045-51  0,038-42         50-125           95

sheep-wool   0,045     0,038            100              5-50 depends on
(Daemwool, washed and impregnated with Mitin)            transport to wash

Conclusion: energy-amortization-times of insulation-materials:

strawbale, reed, cellulose: 0-1 month
cork, sheep-wool: -2 month (depending on transport-distances to
manufacture/wash the material)
cocos-plates: 2-3 month
fibreglass (mineral- or stonewool): 8 month
polystyrol (EPS/XPS): 13- month
polyurethan (PU): 17-18 month (this is the ugly thing people spray between
window- and doorspaces)

2) insulation-price per squaremeter and for 150m2 low-energy house (150m2
living space means ca. 400 m2 wall and roof), all prices in EURO
The following values are necessary to guarantee a wall with U = 0,15 W/m2K
(standard for well-insulated low-energy-houses in Europe)

material    LRTr10    thickness of wall    price/m2   for 150m2

strawbales   0,045          30 cm           3,6        1.453,­

cellulose    0,045          30 cm          18,3        7.326,­

EPS-W15      0,038          24 cm          20,3        8.139,­

fibreglass   0,038          24 cm          23,5        9.419,­

reed         0,045          30 cm          25,6       10.232,­

flax-mat     0,045          30 cm          51,­       20.406,­

cork-plates  0,045          30 cm          87,2       34.883,­

cocos-mats   0,045          30 cm         144,6,­     57.849,­

sheep-wool   0,045          30 cm         163,5       65.406,­

prices for materials are from Austria and can differ with country.

You can combine 1) and 2), the conclusion will always be: strawbale and
cellulose are the ideal insulation-materials (even when you dont use more
parameters than price only). We have only problems in revitalisation of old
buildings, where you cant use these materials.

best wishes
Herbert Gruber
asbn austrian strawbale network
herbert & astrid gruber
email: asbn at aon...

> Von: "Martin Oehlmann" <martin.oehlmann at wxs...>
> Antworten an: "GSBN" <GSBN at lists....com>
> Datum: Sun, 3 Nov 2002 19:34:51 +0100
> An: "GSBN" <GSBN at lists....com>
> Betreff: GSBN:
> Hi,
> We would like to compare production energy and insulation values of regular
> walls (for example: brick + rockwool + cementelements, etc.) with sb-wall
> systems. So far as simple bale-builders we did gently overlook these
> aspects, but are challenged to respond.
> Any idea where to find a list of specified common building materials
> including consumed production energy and insultion values???
> Thanks a lot,
> Martin Oehlmann
> Den Haag
> 0031-70-3650410
> ----
> For instructions on joining, leaving, or otherwise using the GSBN list, send
> email to GSBN at lists....com with HELP in the SUBJECT line.
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