Posted By Alton on 09/18/2009 6:23 PM
I have no way of knowing the true R-value of Aeonian Brick. Hopefully, I will be able to get an idea from the energy bill after the first house is finished. I do plan to follow up on this since I met the inventor and saw the product some years ago. This technology may work like adobe - that is with diurnal swings in temperature. Time and sufficient data will tell the story.
ASTM C 518 testing sez it's R1.22 @ 8" thickness- that's about as close to "true" as it gets in the R-value rating biz. "Effective R-value" arguments based on thermal mass, solar absorption, infrared emissivity etc are all application & conditions specific, and measure something other than resistance to conducted heat flux.
When the marketing statements are more than an order of magnitude away from an ASTM test result the BS meter hits the stops. The reference to "...a coating applied will give the home a R-20 heat resistance..." for achieving R21 reads like something lifted from the Big Book of Insulation Snake-Oil Marketing. (Applying a "coating" of 2lb foam, 3" thick ought to about do it... :-) )
I'm sure it has significant thermal mass, which will reduce & delay peak cooling loads, but it would be a mistake to build a house in a 5000+ HDD climate with Aeonian Brick as your primary thermal insulation in lieu of an R20 SIP or ICF (or even 2x6 lo-density batt stick-built). Thermal mass can be a good thing, but rarely is it the primary thing for efficiently managing thermal loads year-round.
If they have other/better testing data to back up the R21 claim I'd like to see it. They're effectively claiming K-values higher than perlite or vermiculite insulation, yet their 8" uncoated sample tested only 10% higher than the ~R1.1 you get out of standard 8" concrete block (arguably "in the noise" of sample & testing variation.) Barring any further
data, I'll assume it's R1.22, at 8" thickness, as tested.
Autoclaved aerated concrete (AAC) products are similarly high mass, yet test at an order of magnitude higher in R-value at equivalent thicknesses (eg: http://www.safecrete.com/aac/products/techmanual/pdf/thermal.pdf ) AAC 8" wall houses will likely outperform 2x4 & batt stick built every time, but will likely underperform 2x4 & batt & R5 foam sheathing.