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<TITLE>Re: [GSBN] R value export straw blocks?</TITLE>
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<FONT FACE="Arial"><SPAN STYLE='font-size:9pt'>Hello Lance,<BR>
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A delayed reply on this.<BR>
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A company in California called Oryzatech (<a href="http://www.oryzatech.com/">http://www.oryzatech.com/</a>) has for years been in the development of manufacturing a compressed straw block called Stak Block (see attached fact sheet). They have made claims of an R-value of 3.89/inch (see 2nd attachment). I like this product in many ways and think it has tremendous potential. However I’m skeptical of the R-value claim because I haven’t seen a bona fide testing report, and it’s hard to believe the R-value of a compressed straw block would double compared to a typical straw bale. <BR>
<BR>
The R-value for a straw bale, from the most trusted test in the US (the 1998 guarded hot-box test at Oak Ridge National Laboratory) is R 1.3/inch laid flat and R-2/inch on-edge. This is still a matter of debate, but this is what the testing showed. The difference in R-value per inch is explained by the predominant orientation of the straw in a bale (or at least in the bales tested). <BR>
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Though counterintuitive, it’s possible a compressed bale would have a higher unit R-value than a normal bale, if by being compressed it confines more air spaces. Thermal resistance is all about maximizing the number of confined air spaces and reducing thermal bridging. Regarding the latter, I would expect the thermal bridging across a bale would increase when it is compressed. There is likely an optimum density for straw that will yield the highest unit R-value, but this has yet to be researched and demonstrated.<BR>
<BR>
Another point of thermal resistance comparison is polyiscocyanurate, which has the highest unit R-value of any foam plastic insulation at R 5.6/inch. For years polyiso claimed an R-value of 6.0/inch (or higher), but it was adjusted downward a year ago under new testing protocol. (Sorry to bring a distasteful petrochemical insulation into the discussion of natural insulation! It does have quite an ability to insulate however.) Fiberglass insulation is said to be R3.1 to R4/inch (material only, not including thermal bridging of framing).<BR>
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Regarding density, from the Stak Block fact sheet, the 1’x1’x2’ blocks weigh 30 pounds. So they are 15 pcf or 240 kg/m3. Peter’s compressed bales are 468 kg/m3. Those are quite dense, almost twice as dense as the Stak Blocks, and 4 times as dense as a typical straw bale. Even if you trust the R-values I’m stating for a typical straw bale and for a Stak Block, I don’t know how you would reliably extrapolate them to a denser block. The obvious answer is to subject Peter’s blocks to a reliable test.<BR>
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You or Peter Torok might contact the co-founder of the company Stak Block to better understand nature of their blocks and their tested thermal resistance. Ben Korman: <a href="d2bdesign@gmail.com">d2bdesign@gmail.com</a><BR>
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Speaking of Peter, was he ever seconded and brought into GSBN?<BR>
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I hope this is helpful.<BR>
<BR>
Best.<BR>
<BR>
Martin<BR>
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</SPAN><SPAN STYLE='font-size:8pt'><B><I>Martin Hammer, Architect<BR>
</I></B>1348 Hopkins St.<BR>
</SPAN><SPAN STYLE='font-size:7pt'>Berkeley, CA 94702<BR>
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On 1/1/15 7:41 PM, "Lance Kairl" <<a href="sabale@bigpond.com">sabale@bigpond.com</a>> wrote:<BR>
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</SPAN></FONT><BLOCKQUOTE><FONT COLOR="#1F497D"><FONT SIZE="5"><FONT FACE="Calibri, Verdana, Helvetica, Arial"><SPAN STYLE='font-size:11pt'>Any one have an idea on R value for super compressed export Bales.<BR>
<BR>
Any info will be passed on ,<BR>
Although I should nominate Peter to join the list.<BR>
Is there a seconder out there, and then I will fill you in on his good works.<BR>
<BR>
Regards lance kairl<BR>
Hosue of Bales.<BR>
<BR>
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</SPAN></FONT><FONT SIZE="4"><FONT FACE="Tahoma, Verdana, Helvetica, Arial"><SPAN STYLE='font-size:10pt'><B>From:</B> Peter Torok [<a href="mailto:torokenterprise@me.com">mailto:torokenterprise@me.com</a>] <BR>
<B>Sent:</B> Thursday, 11 December 2014 1:13 PM<BR>
<B>To:</B> House of Bales<BR>
<B>Subject:</B> R value<BR>
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</SPAN></FONT><FONT SIZE="5"><FONT FACE="Times New Roman"><SPAN STYLE='font-size:12pt'>G'day lance, <BR>
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As discussed these bales are very well compacted, the dimensions are 400x500x480 45kg or 400x500x240 22kg baled at less than 12% moisture and compressed at 5000 psi. If the bales were sitting on the 400 side, the straw runs horizontal. I inquired about lowering the pressure and he felt the integrity of the bale would be jeopardized, but more pressure can still be applied. I hope that is enough information to calculate a rough R value for both thickness', I look forward to hearing what you come up with. Thanks for helping me out with this, it's very much appreciated.<BR>
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</SPAN></FONT><FONT SIZE="5"><FONT FACE="Times New Roman"><SPAN STYLE='font-size:12pt'>I have found old studies from around 2003 that calculate between R1.4-2.4 US measure / inch<BR>
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<FONT COLOR="#1F497D"><B>This R1.4 – 2.4 relates to standard housing bales,<BR>
Export ones may equate to the R value for Timber??<BR>
</B></FONT><BR>
Regards Pete Torok<BR>
</SPAN></FONT></FONT><FONT FACE="Arial"><SPAN STYLE='font-size:9pt'><BR>
</SPAN></FONT><FONT SIZE="5"><FONT FACE="Times New Roman"><SPAN STYLE='font-size:12pt'><B>Earth Wood & Straw<BR>
</B></SPAN></FONT></FONT><FONT FACE="Arial"><SPAN STYLE='font-size:9pt'><BR>
</SPAN></FONT><FONT SIZE="5"><FONT FACE="Times New Roman"><SPAN STYLE='font-size:12pt'><B>0411 304 794 <tel:0411%20304%20794> <BR>
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