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R-30 Per Inch? Vacupor

jackofalltrades777 | Posted in Green Products and Materials on

I read online about a new product called Vacupor that claims R-30 per inch. Is this true?

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  1. iLikeDirt | | #1

    Per the data sheet, R-30 is when measured at 1 millibar of pressure:

    Measured at ambient pressure (i.e. the way it'll actually be installed), the R-value is 7.7. Still good, if it's true, but only slightly higher than polyurethane when it's cold or polyiso when it's hot.

  2. user-4524083 | | #2

    Per the same data sheet, you cannot put screws or nails into or through it, and it cannot be cut, so I'm not sure of its applicability, even if these R- value claims are true in any way( which I doubt).

  3. GBA Editor
    Martin Holladay | | #3

    Vacupor panels are not new. Vacupor insulation is a type of vacuum insulated panel (VIP). These have been around for a while, and they have been used in a few specialized appliances. As the manufacturer notes in the spec sheet, "Vacupor NT is not approved by the German building and construction authorities for building applications."

    In spite of this fact, I know of at least one construction project that ignored the manufacturer's recommendations and went ahead and used Vacupor panels on a building. The panels were used over ten years ago for the Waldsee Biohaus in Bemidji, Minnesota -- the first certified Passivhaus building in the U.S.

    I wrote an article for the November 2006 issue Energy Design Update describing that project. I wrote:

    "The R-value of VIPs, like that of Thermos bottles, depends up a vacuum. VIP technology is not particularly new; engineers have been experimenting with vacuum-insulated panels for years (see EDU, January 1994 and February 1996). Although some experts have predicted that VIPs will soon be used in refrigerators or buildings, their widespread adoption has been limited by their high cost. ...

    "The architect specified Vacupor VIPs manufactured in Germany by Porextherm. Each 2-inch-thick panel measures 22 ½ inches by 46 ½ inches; according to the manufacturer, the panels have an R-value of 60 (R-30 per inch). Each Porextherm panel is a rectangular aluminum bag filled with fibrous material mixed with fumed silica. As part of the manufacturing process, the bag is evacuated and sealed. “The aluminum is very thin, just like the aluminum foil you use for barbecuing chicken,” says Pearson, who installed the Vacupor panels above the plywood roof sheathing. “It feels like Thermax foam -- a little bit spongy when you squeeze it. But we didn’t want to squeeze them too hard. The durability of the panels is still one of my concerns. If it’s ever done again, I think there should be some type of housewrap or foam installed underneath the panels to protect them, rather than installing them up against the plywood and the splinters.”

    "Since the panels become worthless once they lose their vacuum, they had to be handled carefully; even a pinprick can ruin a panel. “Installing the vacuum insulation panels was challenging,” said Dehler-Seter. “Every time they were moved or scratched we had to worry about losses. In the end, about eight or nine panels lost their vacuum. The panels are guaranteed for 35 years as long as there is no mechanical puncturing. It is still a very tricky building component, and we don’t recommend people start using them just now.”

    "VIPS were installed on the plywood roof sheathing of one of the BioHaus’s flat roofs, between 2x6s on edge. (The 2x6s were tapered to provide a slight slope to the roof.) The 2x6 bays were then filled up with rigid foam, and the roof assembly was covered with a second layer of ¼ -inch plywood sheathing. Since the VIPs cannot be pierced, fastening them to the exterior of the 2x6 walls presented a challenge. “To install the vacuum insulated panels on the walls, we basically stacked them,” said Zetah. “They’re held with a little bit of adhesive.”"

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