Below is a short summary and detailed review of this video written by FutureFactual:
Flamethrower vs Aerogel: Veritasium Demonstrates Aerogel Insulation Capabilities
In this Veritasium experiment, Derek Muller tests the insulating power of aerogel by subjecting a 1 cm thick blanket to a flamethrower and measuring heat transfer to the far side. The air-filled nanopores in aerogel, which can be up to 99.8 percent air, dramatically slow diffusion and conduction, especially when embedded in blankets like Pyrogel XTE. The video contrasts silica aerogel with Pyrogel XTE blankets and demonstrates how a thin Alon aerogel coating enables “safe touch” even at temperatures well above boiling. The discussion then shifts to cryogenic uses, including liquid nitrogen and NASA applications, and ends with a compelling industry case: aerogel-enabled pipe insulation for subsea oil pipelines that dramatically reduces required pipe diameter and ship time. The verdict: aerogel performs exceptionally well, often outperforming conventional insulations.
What is Aerogel and Why It Matters
Veritasium's video introduces aerogel as one of the most effective insulating materials, then contrasts two practical forms: Pyrogel XTE, a fiberglass blanket infused with aerogel, and bare silica aerogel. Dr. Stephen Steiner explains that the material’s nanoscale sponge-like pore structure traps air and disrupts heat transfer, while the solid network itself is a poor conductor of heat. This foundational explanation frames why aerogel can outperform many traditional insulators in real-world applications, even though its pristine form is fragile and impractical for everyday use. "air gel can be up to 99.8% air, but it's a better thermal insulator than air because those pores are so tiny that hot air struggles to diffuse through them." - Derek Muller
Materials and Test Setup
The test uses Pyrogel XTE, a 1 cm thick blanket, and a silica aerogel blanket for comparison. Derek notes that aerogel in blanket form is robust enough for engineering use, while the bare form is fragile. Dr. Steiner adds that Pyrogel XTE is three times better than polyurethane foam for insulating large pipes, enabling dramatic reductions in outer pipe diameter and unlocking pipeline capacity that saved billions of dollars. "It's 3 times better than polyurethane, so I can take this much polyurethane foam and shrink it into an insulation that's that much aerogel now." - Dr. Stephen Steiner
Extreme Heat: Flamethrower Test
In the main heat challenge, a flamethrower is directed at the aerogel blanket from a mere centimeter away. The near side reaches temperatures well over 600°C, while the far side remains around 50°C or lower for an unexpectedly long period, illustrating the blanket’s heat barrier. The experiment includes a dramatic Hershey's Kiss test to show rapid heating without protective insulation, underscoring the stark contrast between uninsulated objects and aerogel-protected surfaces.
Safe Touch Demonstration
To address how heat can be managed safely, the team coats a metal plate with about 1 millimeter of Alon aerogel. An uncovered area reaches roughly 126–127°C, but the aerogel-coated surface remains approachable, and water droplets on the bare metal boil while the coated area remains tolerable to touch. "Safe touch, so that something that would normally instantly burn you, something hot enough to boil water, you could hold your hand on for minutes and it wouldn't hurt you at all." - Dr. Stephen Steiner
Cryogenic Applications and Everyday Warmth
The video then turns to the cold end of the spectrum. Cryogel submerged in liquid nitrogen remains flexible, a crucial property for cryogenic systems used in LNG facilities and NASA missions. Aerogel-based coatings and blankets also find their way into ski jackets and pockets to keep devices warm in extreme cold, illustrating the material’s versatility from extreme heat to cryogenic environments.
Industrial Impact: Subsea Pipelines
Dr. Steiner describes the killer app for aerogel in subsea oil pipelines. In a pipe-in-pipe configuration, insulation mass and outer-diameter reductions enable large-diameter pipes to be laid by far fewer ships. Aspen Aerogels’ insulation delivers three times the performance of polyurethane, allowing ships to lay more pipe with less equipment and time. This capability has eliminated backlogs and saved billions, transforming offshore construction economics and reliability.
Conclusion: Aerogel Wins the Heat Battle
The test eventually reveals the limits of the flamethrower as fuel-depletion and safety measures intervene, but the data speak clearly: the aerogel blanket resists heat transfer far more effectively than uninsulated materials. Derek finalizes the narrative with a definitive verdict: "In the battle of flamethrower versus Aerogel, Aerogel definitely won." - Derek Muller