What Is Aerogel Insulation? | The Solid That’s Mostly Air

Aerogel insulation is a synthetic, highly porous material that delivers extreme thermal performance in a thin, lightweight layer.

If you’ve ever wondered what material insulates better than fiberglass, foam, or mineral wool while taking up a fraction of the space, the answer is aerogel. It holds over a dozen Guinness World Records, including the lowest-density solid and the best solid insulator. It’s used everywhere from subsea oil pipelines to winter jackets.

Here’s what aerogel insulation actually is, why it performs so well, and the differences between the products sold under that name.

What Makes Aerogel Such A Good Insulator?

Aerogel is the insulating phase of the material — over 90% air by volume. That air is trapped inside a silica structure so fine that it nearly eliminates the three ways heat moves: conduction, convection, and radiation. The result is some of the lowest thermal conductivity values measured in any solid.

Product data sheets for aerogel blankets commonly report thermal conductivity around 0.015–0.020 W/m·K, depending on the product and test conditions. By comparison, conventional fiberglass insulation typically lands near 0.04 W/m·K — meaning aerogel insulates roughly twice as well per unit of thickness.

Because it’s so thin for its performance, aerogel is the default choice where space is tight: industrial piping, subsea equipment, and high-end outdoor gear.

How Is Aerogel Insulation Made And Sold?

Pure aerogel is fragile, so manufacturers compound it with fibrous reinforcements — usually glass fiber, polyester, or ceramic fiber — to create usable blanket products. The aerogel is the insulating phase; the fibers provide strength and flexibility.

Aerogel insulation comes in several forms, and the differences matter:

• Blankets and boards for buildings and industrial equipment.
• Strips and subsea products for pipelines.
• Powders and sheets for specialty applications, including clothing.

Given this range, one of the biggest mistakes is treating “aerogel insulation” as a single identical product. Properties like density, water resistance, and maximum use temperature vary widely, so check the spec sheet for the exact product you’re considering.

Two main standards govern aerogel insulation depending on the application. ISO 22482:2021 defines aerogel blankets as factory-made products used for thermal insulation in buildings. ASTM C1728-22 covers flexible aerogel thermal insulation more broadly, with a continuous operating temperature range from -321°F (-196°C) to 1200°F (649°C).

Mixing those two standards is a common error: the ISO standard is for building blankets, while the ASTM spec covers flexible aerogel insulation across more demanding environments.

Real Aerogel Spec Sheets: What The Numbers Mean

To see what a real aerogel product looks like, consider Pyrogel HPS, a widely used industrial blanket. Its manufacturer lists it as ASTM C1728 Type III, Grade 1A, with a maximum use temperature of 650°C (1200°F), compressive resistance of at least 3 psi at 10% deformation, and water vapor sorption of ≤5%. It also reports a flame spread index of ≤5 and a smoke developed index of ≤10.

One number does not tell the whole story. Thermal conductivity values vary by product form, test method, and temperature, so relying on a single figure from one brochure can mislead you. Always cross-check the spec sheet against the standard that applies to your project.

Corrosion compatibility also matters in industrial settings. Pyrogel HPS reports a pass on ASTM C795 for use over austenitic stainless steel and a pass on ASTM C1617 for corrosiveness to steel — checks worth confirming for any aerogel product you spec for metal equipment.

Where Is Aerogel Insulation Actually Used?

Aerogel insulation appears in buildings, industrial piping and equipment, subsea pipelines, and high-performance consumer products. In construction, it solves the classic problem of retrofitting insulation into walls that have no cavity to fill. In industry, it insulates steam lines and cryogenic equipment where space is at a premium.

For everyday buyers, the most visible use is in aerogel insulation jackets that pack serious warmth into a thin, flexible layer — the same material that protects pipelines now protects people in extreme cold.

Moisture resistance is a point where products genuinely differ. Many aerogel data sheets emphasize hydrophobicity and low water absorption, but performance varies. Some aerogels handle humidity well; others are better in sealed industrial systems. Never assume two aerogel products share the same water resistance or vapor sorption values — verify the spec sheet for the specific product.

FAQs