Thoughts on Insulation
“Insulation: Thermal Performance is Just the Beginning” [
1) Regarding polysio insulation, if the conductivity of the hydrocarbon blowing agent is indeed lower than HCFC-141b, then the insulation performance should be better, not worse.
2) I’m less convinced than you that using used newsprint as insulation is downcycling. In a way, permanent building insulation is a higher use for wood fiber than a daily newspaper!
3) I make my choice of insulation material based on a number of factors, many of which you touched upon in your article. In any type of construction, the ability to ensure that the building will get a continuous, robust, effective air barrier is a major input to my choice. In wood-frame housing, I use a lot of cellulose, which I think is the best environmental choice, and very effective. I use it when I know the builder and the cellulose subcontractor. In wood-frame applications where I think it’s unlikely there will be good attention to air-barrier details, I choose low-density spray polyurethane foam (SPF), like Icynene or Demilec. I’ve been asking for exterior application of high-density SPF in cavity-wall buildings, and layered, rigid polyiso boardstock in roofs and over steel framing, so that I have the best likelihood of getting an airtight building.
Marc Rosenbaum, P.E.
Meriden, New HampshireEditors’ reply:
Marc wins last month’s “catch the error” award. The conductivity of the hydrocarbon blowing agent is higher—not lower—than that of HCFC-141b. We have made the correction in our online BuildingGreen Suite.
(2005, March 1). Thoughts on Insulation. Retrieved from https://www.buildinggreen.com/op-ed/thoughts-insulation