Icynene has rolled out a new type of closed-cell spray insulation that uses water as a blowing agent, eliminating the global-warming potential of the hydrofluorocarbon (HFC) blowing agents in most closed-cell foams.
ProSeal Eco is described as a medium-density foam, weighing 2.2 pounds per cubic foot when cured, roughly four times as dense as Icynene’s open-cell foam and about equal to other types of closed-cell foam.
Icynene says the insulation has an R-value of 4.9 per inch, compared to R-6 to R-6.5 for closed-cell foams. But, the company adds, ProSeal Eco will show less of a drop in R-value over time than foams made with HFC blowing agents.
Icynene’s open-cell foam has an R-value of 3.7 per inch. Using those values, a 2×6 wall filled with conventional closed-cell foam would have an R-value of 35.75 (between the studs at the middle of the wall) while a wall sprayed with ProSeal Eco would have an R-value of 26.95. A wall filled with Icynene open-cell foam would have an R-value of just over 20.
Insulation can serve as a vapor barrier
A key difference between open- and closed-cell foam is how well they stop the migration of moisture into wall and roof cavities. Icynene’s closed-cell foam has a vapor permeance of less than 1 perm at a thickness of 2.4 inches, the company says, making it a Class II vapor retarder.
Open-cell foams are not considered Class II vapor retarders at any thickness.
The company says the closed-cell insulation will be helpful in exterior wall cavities, in floor assemblies over damp crawlspaces, and in walls or floors below grade where controlling dampness is important. And with a higher R-value per inch than open-cell foam, it also will be useful to builders trying to get high performance at lower thicknesses.
Improved performance comes with a higher price. Icynene didn’t offer estimates of how much more expensive ProSeal Eco would be, suggesting instead to use the dealer locator on its web site and get a local quote.
A Peabody, Massachusetts, installer said that filling a 2×6 wall with Icynene open-cell foam would cost about $2 per square foot, while ProSeal Eco would cost about $3.50 per square foot.