Embodied energy is the
energy consumed in producing products. Mineral insulation comes from furnaces
that gulp natural gas to melt sand, slag, or rock. Foam plastics are
petrochemicals. They are literally made out of energy! Cellulose insulation is
made by processing recycled wood fibers through electrically driven mills that
consume relatively little energy when they are operating, and which can be shut
down completely with the flip of a switch at the end of the shift -- or even for
lunch and coffee breaks. Fiber glass, rock wool, and plastic insulation may have
from 50 to over 200 times more embodied energy than cellulose.
Preferred Building Systems, our modular home factory
installs dense-pack cellulose at a 3.8 per inch R value and provides tremendous
air sealing along with the additional air sealing we install. The cellulose is
85% post consumer recycled newspapers with a fungicide and fire
cellulose insulation made with recycled paper is a good green option
with performance - high R value and low ghg emissions
On 11 Dec 2008, at 12:55, Robert Riversong wrote:
Icynene vs straw is a good example of the difficulty in making
appropriate choices of "green" materials.
While I don't think that spray foams should be used in new
construction, stuffing straw into existing walls for a retrofit/upgrade
is not a sensible option and with a limited wall cavity Icynene may be
the best alternative for renovation. Even for new construction, straw
bales - with their low R-value per inch (—1.45, about the same as
lumber) may not be the best choice.
Besides having no global warming or ozone-depleting installation
by-products, Icynene has only a little more embodied energy per cubic
foot than fiberglass (not that I would recommend fiberglass for
anything), typically less installed embodied energy (since framing bays
are not generally completely filled) and better efficiency payback.
Best use of remaining fossil energy and petrochemicals? Not so
simple to discern.
--- On Thu, 12/11/08, Michelle Smith
Mullarkey <[log in to unmask]>
Point taken. I admittedly was thinking of
products like Icynene vs. straw, but it seems fossil fuels really are
part of our entire world.
On 12/10/2008 6:21 PM, Robert
Fossil fuel is still used to manufacture
and transport the majority of green building products (not
natural building products such as straw bales)...
I'm afraid that fossil fuels
are used for the production of most straw and since some of it
is coming from Canada, there's also transportation costs.
"Natural" building materials are not necessarily immune from
the environmental costs of other materials.