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GBlist: Foam insulation and blowing agents terminology



This stuff may not seem important, until you're trying to get an accurate,
technically correct answer from someone. Your work sounds great, Tim. Now,
to clear a couple of issues with the materials you're using:

>Styrofoam of course, is relatively low in R value but does not produce
>HFCs and doesnt seem quite as nasty.
>

Styrofoam(TM) is trademark of the Dow Chemical Company for their EXTRUDED
Polystyrene (XPS) Insulation. This is the closed-cell stuff, also known as
"blueboard", and it _DOES_ contain ozone-depleting HCFCs. It's the same as
Owens Corning's pink board, which used to called Foamular(TM) from UC
Industries.

The "plain, white stuff" you're talking about is probably EXPANDED
polystyrene (EPS), also known as "beadboard". It is blown with the
hydrocarbon pentane, which does not affect the ozone layer.

Now, about those initials:

HCFC = hydrochlorofluorocarbon, which is less damaging to the ozone layer
than CFC (= chlorofluorocarbon) by about 1/20, but still an issue.

HFC = hydrofluorocarbon, which contains no chlorine, hence doesn't bother
the ozone at all. Some of these are starting to replace HCFCs in
refrigeration and cooling equipment, and in some spray foams and foam
sealants (details in the forthcoming October issue of EBN).

Sorry for being so picky, but these things get confused so often!

Nadav Malin
Environmental Building News


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