Aerogel Insulation Advances
Nicknamed “frozen smoke,” aerogel is extremely lightweight material, with a density only 3 times that of air. Only a small fraction of a volume of aerogel is the material itself. Most of the volume is filled with air. This makes aerogel an excellent insulator. (Aerogel provides nearly 40 times the insulation of fiberglass insulation.)
Aerogel can withstand great pressures and is also an excellent sound insulator. Aerogels can also be used to absorb airborne pollutants and have been used to clean up oil spills. NASA also used a section of aerogel as part of its Stardust probe to collect samples of material from the tail of a comet.
Aerogel is available for some high-performance applications, but due to its high cost, it has not been widely used. However, new research from a Malaysian scientist offers the potential to drastically reduce the cost of producing aerogel, and could lead to new possibilities for its use as a building and insulation material.
Dr. Halimaton Hamdan from the Universiti Teknologi in Malaysia has developed a method of producing aerogel that could reduce the cost of producing aerogel by 80% by using agricultural waste from rice husks as the feedstock. Rice husks evidently have a high silica content, and silica is the main constituent of aerogel. In addition to potentially being able to produce aerogel for one-fifth the current cost, this also addresses a problem with disposing of rice husk waste.
Because aerogel is translucent, rather than completely transparent, one of the places it has first been used in architectural applications has been in daylighting panels. Commercial applications of aerogel are from companies such as Kalwall and Advanced Glazings, both of which produce diffuse lighting windows that incorporate aerogel to produce panels that transmit light while having an insulation R-value equal or better than that in an insulated wall in a new home. These windows aren’t for vision, but they allow a high percentage of light to be transmitted, allowing for diffused daylighting, which is a better method for lighting without producing unnecessary glare. However, until now, these windows have been used only in special instances because of their high cost.
If prices for aerogel become significantly lower, it should be possible to see highly insulating panels that can replace traditional forms of insulation. Even more compelling is the possibility for retrofitting existing buildings with relatively thin panels that can significantly improve their thermal performance. Since buildings last for such a long period of time, retrofit solutions are going to become an important part of reducing the amount of energy used by buildings without needing to demolish and replace everything that has already been built.
Links:
Green Building Elements: Super Insulating Vacuum Glass
Green Building Elements: Better Daylighting
NASA: Aerogel fact sheet
Image Source: NASA via Wikipedia
via: EcoGeek
If you looked at a 1/8″ thick aerogel panel in a standard 4′ x 8’size, it would weigh 28.3 grams (about the weight of 10 pennies) and, at almost 40x the insulation value of fiberglass, would be roughly equivalent in insulation value to a well insulated 2×4 stud wall.
And can anyone purchase these 4 x 8 sheets of Aerogel? No?
Well, then, keep dreaming. When it arrives at Home Depot, and can be delivered there without damage, then we can talk about a practical product.
“Talk about it, talk about it, talk about it, talk about it…. Won’t you take me to…. FunkyTown?”
Wow. Now large skylights made with aerogel panels could provide light without the downside of sound and thermal transmission. When will they be available?
What makes the cost so high? cant we throw a bunch of funding into an assembly line of these?
I don’t know enough about the manufacture of aerogel to give you a complete answer. Part of the cost is in the refinement of silica. Since rice husks have a high silica content (20%, I believe) they make a good supply feedstock, and this is at the root of the new production method.
@Chuck Orr - as I mentioned, manufacturers including Kalwall and Advanced Glazings are presently making windows and panels with aerogel. But they are very expensive.
There are many sources of silica, straw being one of them. Some entrepreneurial Chinese boys will pick this up and be selling us Made in China insulation before we Americans can get up to eat lunch. This will not be lost to mankind, only to our workshops because we don’t feel we have too anymore, we proved ourselves in the WWII era and now we’re done!
Uncle B, you are right. Our dependance on the industrial age as made us prehistoric in the coming web v2.0 age. Our power is not limited by our potential, simply our lack of ability to be flexible. Our nation is led by large companies with no ability to do what the market calls for. Even if they were built to be that flexible, good luck having the administration with the Gonads to pull the trigger.
Here is a page on how silica aerogels are made.
http://eande.lbl.gov/ECS/aerogels/sa-making.html
there seem to be several factors that severely limit aerogel manufacturing. One is that the time required to manufacture a piece is heavily dependent on its thickness, because many steps are slow diffusion processes. Another factor is that the pressures and temperatures involved are high and must be precisely controlled, thus require a special environment and a batch-type manufacturing process.
Another consideration is that silica aerogels tend to flake and release micro-particles into the air. I’m not sure if these would be more dangerous than the micro-particles produced by fiberglass, but it is a potential safety concern. Aerogel also has a strong dessication effect, absorbing moisture strongly enough to cause “burns” on human skin after prolonged contact. This, along with aerogel’s fragility, would make installation a tricky process if you were to use large panels as insulation.
Of course, granulated aerogel can be embedded into other materials to mitigate a lot of the logistical problems associated with it, but you also lose a significant portion its insulation potential (since pretty much everything is significantly more thermally conductive than aerogel). It depends on how much insulation you need, I guess, and how much space you have to put it in.
That’s a great link you provided, Mike. Thanks very much.
As to an insulation product made using aerogel, I think it would be necessary for it to be completely encapsulated. It’s far too fragile to stand up to a direct loose-fill application (like fiberglass). It would have to be something like a board that incorporated an aerogel inside.
“Uncle B” is right, there is no longer any urgency left in the USA . Part of the reason I think is legal issues and regulation. The roadblocks to good ideas in our fair country make the majority of aspiring inventors and entrepreneurs run for cover when they first encountered these obstacles.