Q: What is a better insulation for green-minded homeowners: shredded blue jeans or spray foam insulation?
I know shredded jean insulation is good because the materials are recycled and safe. But, would a green-mined homeowner be better off going with spray foam insulation for efficiency's sake? Thanks.
Posted in Going Green on
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John M from
Four Points Consulting Group
New York, NYA: Foam is much better but there is no perfect product for insulating walls.
Ultra Touch cotton batt insulation contains no chemical irritants and there are no VOC concerns. This insulation contains as much as 85% post-industrial recycled natural fibers and it is safe for workers, homeowners and the environment. The dense cotton will not allow air to penetrate it and it has an r-value of 3.5. But exterior walls have many obstructions such as wiring, electrical outlets, and plumbing that will cause gaps in batt insulation.
Polyurethane spray foam’s great feature is that it expands, surrounding any obstacle. It seals every opening, providing excellent air barrier properties. It’s not all good news though. Environmentally speaking, there are disadvantages to foam despite its benefits. Polyurethane is of course plastic, made from petroleum and takes a considerable amount of energy to produce. This high embodied energy must be weighed against all the energy saved for the life of the house or building.
When foam is applied, they will try to spray it to edge of the studs and then shave off any excess so that the drywall can be installed with no humps or bulges. This waste goes right into a landfill. Additionally, most spray foams rely on chemical blowing agents that contribute to greenhouse gasses. During application, inhalation of these chemicals can cause significant health risks if workplace precautions are not followed. These gasses will dissipate after 24 hrs and there is no health risk for the owners.
For new residential homes, we typically specify open cell foam with at least 2” of rigid foam on the outside of the wall cavity. In New York City, interior space is a premium and R-value drives our strategy. We use closed cell foam for exterior walls in the apartments and brownstones we renovate. Once inside the building envelope, the focus shifts from thermal comfort to preventing sound transmission. Cotton batting is very easy to install and gives the best sound deadening properties for standard wall assemblies.
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Brian B from
K-Co Construction
San Diego, CAA: Another Option
Another green option for insulation is Green Fiber. It is made of 85% recycled paper fibers that have been treated for fire and insect resistance. It is applied by spraying which gives you the complete void filling ability of the foam, but the waste is vacuumed up and sent back to the truck to be applied. It is much safer than traditional fiberglass insulation for the workers and homeowners, much less expensive that recycled jeans, and has great sound deadening qualities. At K-Co we almost exclusively use Green Fiber and have found the cost to be only 12% higher than traditional fiberglass, compared to recycled jeans being 100% higher cost than traditional fiberglass.
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Damien C from
Moonworks Home Improvement
Woonsocket, RIA: The Golden Question
There is a lot of debate as to what insulation material is the most green. There are pros and cons to many different materials - each material has its own "green" camp. Sometimes natural materials are sprayed with chemicals to make them flame retardant and aren't as green as first thought....
Below are some great resources to help you on the quest for your answer. My personal opinion is to present the facts and let the customer decide for themselves.
Insulation Blog Series: http://www.moonworkshome.com/Blog/?Tag=Insulation+Blog+Series
A great resource that is 100% transparent is the Pharos Project. The project rates building materials on a variety of green factors.
Read more about the project here: http://www.moonworkshome.com/Blog/bid/23380/Green-Building-Pharos-Project-Bringing-Transparency-to-Building-Materials
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Angela S
Kernersville, NCA: Spray Polyurethane Foam insulation is the "Greenest" of the Green.
I think the following passage found in the <a href="http://www.insulstar.com" target="_blank">InsulStar.com</a> featured article "How 'Green' Is SPF?" article on spray foam insulation can also help to answer this common question.
"If one chooses to define “green” by such things as
recycled content or use of natural materials, cellulose or
cotton/wool fiber could be considered the “greenest.”
However, comparing the various “green insulations” in more
quantifiable terms, such as R-value at similar thicknesses,
overall energy savings and effect on indoor air quality may
be the most accurate way to assess their “greenness.” By
those criteria, spray polyurethane foam insulation would
appear to be the “greenest” of the “green.”"
The full article can be found at <a href="http://www.insulstar.com/uploads/How GREEN is SPF SF0808L.pdf" target="_blank">How Green is SPF</a>?
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Angela S
Kernersville, NCA: Missing links - Spray Polyurethane Foam insulation is the "Greenest" of the Green
Sorry! These links did not make it to the previous post.
www.InsulStar.com is the home page of the site and the article "How GREEN is SPF?" is
http://www.insulstar.com/uploads/How GREEN is SPF SF0808L.pdf
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