The most effective building insulation materials currently in widespread use are polystyrene and polyisocyanurate panels and polyurethane spray foam. These materials have an R-value of about R-5 to R-6 per inch.
Fiberglass batts, which are widely used in residential construction, have an R-value of about R-3 per inch. Aerogel is an intriguing material which has an R-value of R-10 per inch, but it is still very expensive to produce and, because it is so fragile, it is difficult to incorporate into building materials. As these R-Values increase, so does the efficiency of heating and cooling, the largest slice of the home power-use pie.
Specialty panels with significantly higher performance are available. Vacuum boards can provide as much as R-30 per inch. And a company called Glacier Bay offers Barrier Ultra-R panels, which use aerogel inside a sealed, evacuated panel. Ultra R panels offer R-50 per inch insulation value, roughly 10X better than a conventional polystyrene or polyiso insulation board.
By incorporating the aerogel core inside the vacuum panel, the panels require a less extreme vacuum to obtain their insulation performance. And the reduced pressure differential due to the lower vacuum level translates into a longer life for the panel. A typical panel needs to have internal braces to keep the panel from being crushed by the outside atmospheric pressure (and these braces reduce the effectiveness of the vacuum insulation by acting as a thermal bridge that lets heat move from one side to the other). Aerogel is a very strong material, and supports the panel faces to prevent them from being crushed.
Even if the panel is punctured and the vacuum is lost, these panels will continue to perform at R-9 per inch, still nearly double a conventional insulation board. And the panels carry a 25 year warranty.
Glacier Bay markets these boards primarily for use in boat refrigerators, where efficiency is key, but they could be used in other insulation applications, albeit at an extraordinary price. Unfortunately, this is not a material that could be readily adapted to building construction without some serious modifications to building methods. Construction sites and traditional building methods do not typically deal well with fragile materials such as this.
At present, for building construction, aerogel is most commonly found in high performance translucent windows. However, with a process that could drastically lower the cost of producing aerogel, these panels could be the prototype for insulation panels that could transform how buildings are built.
Retrofitting older homes (or any buildings, really) to higher levels of insulation is hard because there isn't much space available. Currently, superinsulated buildings are sometimes built, but they tend to have thick walls. Affordable vacuum/aerogel insulation panels might lead to superinsulated building performance with walls that are only a couple of inches thick. Even retrofits might be feasible with a panel only an inch thick that would more than double a building's wall insulation.
via Greenbuilding list - Thanks for the tip, Lawrence Lile
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