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I see that www.buyaerogel.com has begun to offer various insulating blankets, though it seems targeted for industrial use rather than consumer use.

Does this aerogel look like a suitable technology for home insulation in its current form? Or would it not be up to the task (perhaps due to durability, or toxicity)?

How does its insulation performance compare with something more standard, say, polyester blanket?

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Your question is very broad and can't be easily answered. There are few existing products, so the answer is also somewhat speculative.

Aerogels are a form of material, like foam or dust. It's very likely that a suitable house insulation could be made with an aerogel, almost regardless of the detailed requirements that you have in mind (barring contradictory requirements, like "cheap" and "aerogel"), since a wide range of aerogels already exist and some could be used this way.

Current aerogels are typically made from silica gel or carbon particles partly fused together, but could in theory be made from almost anything. You could conceivably replace the aluminium in an alumina aerogel with another metal to get different characteristics, since those are essentially just fused dust (in the same way as humans are essentially just bags of dirty water). The difference between a sintered metal and a metallic aerogel is largely density if we ignore the difficulty of producing it. Silica aerogels turn to dust when crushed, as well.

Since aerogels typically have a much lower thermal conductivity and density than their parent materials, they can be used as insulators. Flammability will typically be higher due to the larger surface area and likely oxygen infiltration over time, even if oxygen was not present when the aerogel was made. Toxicity depends almost entirely on the constituent materials, with silica aerogels being largely inert and minimally contaminated. But carbon aerogels typically burn, and if you made an aerogel with fused plutonium dust it would be dangerous in all the ways that plutonium is.

For home insulation with current technologies, silica aerogels are the best candidate. They are expensive, and somewhat fragile. Unfortunately the current methods for producing them are inherently expensive (supercritical drying at high pressure and temperature).

This product from the site above sells for $2.30 a square foot when 5mm thick, with an R value of about R2.8 W/K/m² (if I've done the maths correctly from 14 mW m-1 K-1), compared to a similar thickness R1.3 foil+bubblewrap for $0.40/square foot here in Australia. The aerogel is also fragile and dusty, where the foil product is not. A layer of foil plus a layer of "earthwool" R2 for a total of $0.70/sq foot and ~50mm thick gives better insulation for a significantly lower price.

I think it's more likely that an affordable aerogel will be made from a carbon lattice, since we have a multitude of different techniques for working with carbon already. Current carbon aerogel thermal insulation (see link below) is made via pyrolysis (combustion) so is usually fragile and chemically reactive, limiting it to specialised applications (most vacuum-related).

The main problem with using aerogels for home insulation is the variety of low-cost solutions already in the market. At the extreme are things like straw-bale insulation, where the raw material is a low-cost byproduct. Many cellulose-based insulators use similar source products, making them equally cheap.

Which is also the problem - to be cost-competitive with existing insulation products the aerogel would have to be better in some way and not significantly more expensive. Many parts of homes don't have significant thickness limitations - it's quite reasonable to have 200mm or 300mm of insulation in walls, and if an aerogel competitor was available that allowed that R value to be achieved in 50mm that would not be a huge advantage.

Here's a pdf presentation (from 1999) on carbon aerogel thermal insulation.

  • Looking at the website more closely, there is a product "Spaceloft" which says it's for insulating buildings and apparel. buyaerogel.com/product/spaceloft Good answer though, thanks – Highly Irregular Mar 17 '14 at 22:54
  • I love the way they use both metric and imperial units. 5mm thick give R2.8 for $2.30 a square foot, compared to R1.3 foil+bubblewrap for $0.40/square foot here in Oz. Three layers of that is half the price of the aerogel (but 15mm thick) and it's not dusty or fragile. Or a layer of that plus a layer of "earthwool" R2 for a total of $0.70/sq foot and ~50mm thick. Obviously the aerogel is a specialist product. (oh, and the conversion is ~12x for R values IIRC, so our R2.8 is your R50-ish, probably). – Ⴖuі Mar 17 '14 at 23:18
  • It seems rather odd to say that "There are no existing products" given the question contains a link to one of several places that sells these products. And it's also incorrect to say that "Many parts of homes don't have significant thickness limitations": in some parts of the world, and in very many cities, they do. – EnergyNumbers Mar 18 '14 at 1:33
  • @EnergyNumbers I'm really only familiar with building codes in Australia and New Zealand, where to meet code walls will normally have a 75-100mm cavity in the centre and there are multiple products available that can meet the insulation requirements in that space. Unfortunately I don't have a link to hand, but even the cheap "earthwool" above will give the usual R4 in a 100mm cavity. – Ⴖuі Mar 18 '14 at 3:09
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    @Ⴖuі worth remembering that in many parts of the world with older buildings, solid walls are common - so the thicker the insulation, the smaller the room when you've finished! Good answer though, thanks. – Flyto Mar 18 '14 at 13:34
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Aerogels show some promise for use in buildings

conductivity is around 0.013 W/mK for commercially available aerogels compared to around 0.04 W/mK for glassfibre quilt and 0.025 W/mK for eps/styrofoam type insulation

Toxicity would probably not be an issue due to the generally unreactive nature of silica aerogels

The most likely health issue seems to be from dust production.

International Agency for Research on Cancer has classified it as not carcinogenic to humans and there's been no evidence of problems from people with long-term exposure.

Its hard to say what durability will be like in buildings as this will take some time to determine.

As well as opaque insulation translucent aerogels can be used in windows and solar collectors.

summarised from: Baetens, Ruben, Bjørn Petter Jelle, and Arild Gustavsen. “Aerogel Insulation for Building Applications: A State-of-the-Art Review.” Energy and Buildings 43, no. 4 (April 2011): 761–69. doi:10.1016/j.enbuild.2010.12.012.

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Available products

Aerogels in composites are typically two to four times more thermally insulating than the next-best alternative.

And since the recent expiry of some aerogel patents, the number of suppliers of these products has started to increase. The Space Loft and Thermal Wrap products at the site linked in the question are indeed aimed at the residential market, as well as the industrial.

The RockWool company now offer Aerowolle, a hybrid of aerogels and rockwool, as well as aerorock id-vpk - internal wall insulation (IWI) which combines aerogel with a plasterboard.

In Britain, the ThermaBlok range includes self-adhesive aerogel strips for fitting on studs and joists, to prevent thermal bridging; wall boards, ceiling boards, floor boards, and an insulating blanket..

You can also get aerogel-composite tiles, for retrofitting insulation on the reveals around windows: one of many cases where very narrow spaces require a material with particularly high thermal-insulation characteristics.

And there are aerogel particles, which can be blended into paints and plasters, for a wide range of applications: suppliers include Sto (StoTherm In Aevero), Fixit (222), Tnemec (Aerolon), Birdair (Tensotherm), Wasco (Lumira aerogel Skylights) and TGP (Profilit channel glass system)

Costs

Given planning-permission constraints (e.g. in Britain), and given the high unit cost of land in many cities, aerogels and other super-insulators have a key role to play: internal space is at a premium, so the space-saving offered by super-insulators can be very valuable. That high pressure on the demand-side, together with an industry that was until recently constrained by patents, means that aerogel composites are (as of early 2014) more expensive, per unit of heating energy saved, than materials such as PIR. When you take into account the economic value of lost space, aerogel products are often cheaper.

Suitability

Wherever space is a constraint, and you've got the budget, aerogel products offer some interesting opportunities. The supply chain is best-developed in and around Germany at present, but is growing elsewhere. Like fibreglass, it can in some forms be dusty and unpleasant to work with: see the material data sheets and take appropriate safety precautions when installing.

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There are already aerogels used in residents that are blankets and much more resilient than other legacy products available. They roll out easily and have none of the issues as fiberglass and other insulation materials.

The product is amorphous silica so comparable to sand, completely safe and comes in forms that are also waterproof, offer sound dampening and heat resistance up to 1200°F (650°C). In Europe, they are standardizing the product for its safety and longevity benefits. One of the latest manufacturers uses aerogel.com website, but are sold through global contractors. It’s expensive, but for high-end home or capital investment it's a small price to pay for quality.

  • Thanks for your answer! I'd love to see links to any other businesses producing or selling it, if you're aware of any. – Highly Irregular Aug 20 '18 at 21:41
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If cost was not an issue and you were simply doing it to remove dust then yes cost aside this particular panel although expensive http://www.buyaerogel.com/product/airloy-x103-large-panels/ The H density class is .043W/m-K So I hope that answers your question and this particular panel is also 10-1000x better at acoustic dampening. It should be noted that at the time I wrote this the panel was apparently $490 30cm x 30cm x 0.5cm.

  • Welcome to Sustainable Living! Are you affiliated with the mentioned website? Posts that do not mention affiliation with recommended products or websites are sometimes marked as spam by other site users and may be deleted. – THelper Apr 3 '16 at 7:37
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I used Aspen Aerogel blanket between a concrete stem wall and the granite sill that was to rest on it. It was great for this special application where space was a premium, and I wanted to stop the bridging of heat from the sill and foundation.

protected by THelper Aug 21 '18 at 7:36

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