wrote in message
...
News wrote:
The British Advertising Standards Authority... [objected to] a brochure
for roof insulation. The brochure stated "TRI-ISO SUPER 9 Insulation for
roofs was... Thermally equivalent to 200 mm of mineral wool when installed
in a roof situation, as certified by the European certifying body, BM
TRADA
CERTIFICATION (following real building trials...
... Actis said they had commissioned BM TRADA Certification Ltd (BM TRADA)
to test, assess and report on the TRI-ISO Super 9 product. They provided
us
with a copy of the BM TRADA Certification and Report dated August 1997 and
said that it substantiated their claims... They pointed out that BM TRADA
had used "in situ" testing involving a real external environment with
variations in temperature, humidity, etc. rather than the traditional
methods of laboratory testing...
... We understood that BM TRADA had tested TRI-ISO SUPER 9 and the mineral
wool in two separate roof installations. However, we noted that BM TRADA
had not used the standard industry methods of testing and that the report
provided by Actis did not include sufficient detail to support their own
methods of testing.
We acknowledged that BM TRADA Certification was a leading multi-sector
certification body accredited by the United Kingdom Accreditation Service.
We considered that the BM TRADA report did not provide enough detail to
support their methodology...
... ie they faulted the test documentation, vs the result.
We understood that RT was a symbol of total thermal resistance and
typically
had the standard unit of measurement of mēK/W. We noted that the claim
"RT=5" was not qualified by any recognised units of measurement e.g. mēK/W
and a small footnote stated only "in situ measured values" without further
explanation. Because the value of 5 was not qualified by any recognised
units of measurement, we considered the claim "RT=5" was ambiguous and
should be qualified in future.
... and they faulted the lack of explicit units in the advertised result.
However, we noted that the BM TRADA report did specify an overall
resistance
(RT) of 5.0mēK/W derived from the in situ testing...
Picky, picky. Reflectix does advertise some system R-values:
http://www.reflectixinc.com/script/p...duct.asp?ID=64
http://www.reflectixinc.com/script/p...duct.asp?ID=77
http://www.majorgeothermal.com/PDFs/.../Solutions.pdf
The US R16.8 crawl space number is interesting.
An important question here is how does other insulation perform 'in-situ' if
measured the same way as this product.
If this product can achieve an RT=5 'in situ', that means the overall
measured insulative performance is 5 m^2-K/W. That performance includes the
affects of convection and radiant heat transfer from the living space to the
product, and from the product to the environs on the other side.
But what is deceptive about this, is that if I were to put a simple piece of
conventional building insulation that has an RT=5 value in the same
circumstance, it would undoubtedly have an 'in situ' performance that is
*better* than 5. Because added to the material's own RT=5, would also be
the affects of the convective layers on each side (just like this product),
and the radiant transfer to/from the surfaces.
Unless this products RT value is calculated by taking the 'in-situ'
performance and *subtracting* the insulative performance of those items
common to *all* installations, the RT value is inflated by those other
factors. Thus when compared with other materials tested in the more
traditional manner, it overstates this product's performance.
daestrom