Aerogel is a category of low-density solid gels in which the liquid has been replaced with gas or air. Insulating your entire house with aerogel sounds crazy at first, but the truth is, aerogel insulation may prove to be pretty effective.
This article will discuss everything you need to know about aerogel and why it might be good for insulation.
What Is Aerogel?
The structural framework of aerogel is usually composed of silica. Thus, silica aerogel is often just known as “aerogel.” Nevertheless, other structural materials have been used to manufacture aerogels, including:
- Iron oxide
- Organic polymers
Regardless of what material is used, aerogel generally has an almost transparent appearance. The high gas content of aerogel also gives it many distinct properties, such as very low thermal conductivity, extremely high porosity, and incredibly low density.
What Makes Aerogel a Good Thermal Insulator?
Aerogel is a good insulator due to its three-dimensional, intertwined porous structure, making it a poor conductor.
The solid part of silica aerogel comprises minute, intertwined, three-dimensional clusters. They make up only three percent of the volume and are extremely poor conductors. The air in microscopic pores makes up the rest of aerogel’s volume.
This air doesn’t have a lot of room for movement, preventing gas-phase conduction and convection. Because of these characteristics, aerogel is the world’s lowest-density solid and most effective thermal management insulator.
Pros of Aerogel Insulation
Low Density and Thermal Conductivity
Aerogel appears translucent because a lot of the material is just air, which also explains its incredibly low density.
They are the lightest solids on earth; even a six-foot block of aerogel will only weigh less than one pound.
Aerogel is also particularly valued for its incredibly low thermal conductivity, which can be as low as 0.015 W m-1 K-1.
High Thermal Insulation
One of Aerogel’s distinctive physical properties is its incredible heat insulation (0.023 W/mK at 100˚C).
When used for thermal insulation, aerogel effectively improves equipment energy efficiency, which also helps cut down emissions and energy costs.
Aerogel has high water-repelling capabilities. In addition, thanks to its hydrophobic nature, it can safeguard operating and insulating components from corrosion and moisture damage.
Aerogel can maintain its shape in high-temperature environments and doesn’t clump, sag, or crack like other insulators. As a result, it resists impacts, vibrations, and frequent traffic reasonably well. Plus, it can be reused after a comprehensive inspection.
Outstanding durability allows aerogel a considerably longer service life.
Thinner aerogel blankets allow for easier installation and removal for repairs and maintenance, reducing installation costs and time.
Incredible Acoustic Properties
Aerogel has terrific acoustic properties, offering much better sound insulation than polyurethane forms.
Cons of Aerogel
Difficult Manufacturing Process
Despite the advancements in production technology, aerogel is still quite hard to manufacture.
The most extensive aerogel panel the industry has managed to make was 90 x 90 cm. And these dimensions were only possible because of highly advanced machines.
If you were looking for aerogels to purchase, the biggest size you would be able to buy is 30 x 30 cm. Special orders need to be placed for bigger sizes.
Price is another reason why many people hesitate to use aerogel.
As mentioned, aerogel is the most effective thermal insulator. Hence, it is accompanied by a hefty price tag.
Furthermore, the expensive manufacturing process means the cost is ultimately passed on to the buyers. Because of this, a silica Aerogel with dimensions 2.5 cm x 2.5 cm x 1 cm costs more than $50.
One major challenge the aerogel industry faces is its brittle nature. While the material is quite strong and can hold several times its weight, it doesn’t hold up well under tension.
According to a report by the U.S. Department of Health and Human Services, exposure to aerogel insulation is linked to upper respiratory tract infections.
The Department’s investigators visited an Illinois facility where employees used aerogel insulators in their projects. The intention was to analyze airborne exposure to materials from aerogel insulation.
The analysis was positive for “Airborne exposures for amorphous silica aerogels.”
Moreover, the interviewed employees attributed dry skin and respiratory tract irritation to handling aerogel insulation.
The above side effects manifested due to the fact that, aerogel particles are respirable in size.
Potential Applications for Aerogel
Aerogel has been used as an insulating material for years. Presently, you can find it in wetsuits, paints, and cosmetics.
The use of Aerogels in the aerospace industry has also increased over time. Most notably, it was used in NASA spacesuits for its incredibly durable and lightweight nature.
The one-of-a-kind material was also used as the insulating material that kept the Mars Exploration Rover warm while on its mission.
One of the more contemporary applications of aerogel includes using it as an insulator for buildings. Home insulation using aerogel entails products such as aerogel sheets and aerogel blankets.
Aerogel windows are another innovative technology that sandwiches aerogel between two glass sheets. They are lighter than triple-layer glass windows and offer a much higher level of insulation.
A recent invention known as cotton aerogel is gaining popularity in various industries. For example, this material can be used as an insulator to substitute traditional bulky jackets.
An astonishing application is cotton aerogel as a hemorrhage control device. It can be inserted into a bleeding cut. As the material expands, it applies pressure on the wound and stops the bleeding.
Aerogel insulation is also ideal for high-temperature applications where other insulations can melt. Thanks to its high melting point of about 1,200℃ (2,192℉), aerogel insulation will not melt easily at high temperatures.
Finally, due to its thinner nature, aerogel insulation is suitable in compact environments with limited application space.
Aerogel vs. Other Insulators
There are various materials used for insulation. Here, we will compare some of the most common types of insulators with aerogel so that you can make an informed decision.
Aerogel vs. Fiberglass
Because of how fiberglass is manufactured, it can reduce heat transfer and is an excellent non-flammable insulator. Another benefit of fiberglass is its low cost.
The main disadvantage of fiberglass insulation is the danger of handling it. The glass powder and minute shards of glass can damage the lungs, eyes, or skin if proper safety precautions aren’t taken during the installation.
Unlike fiberglass, aerogel insulation is efficient. Aerogel has seen declines in costs, too, as it gains popularity in several markets.
Aerogel vs. Mineral Wool
Mineral wool refers to various kinds of insulation, such as glass wool and rock wool. It can be bought as a loose material or in batts.
Most mineral wool does not contain additives to make it fire-resistant. Thus, in extreme heat conditions, mineral wool isn’t an excellent choice on its own.
Instead, you will have to use it with more fire-resistant forms of insulation that can be more expensive.
On the other hand, aerogel is incredibly fire-resistant. It’s the perfect choice for both cold and hot temperature environments.
Aerogel vs. Cellulose
Cellulose insulation is probably one of the most environmentally friendly types of insulation.
Cellulose is made with recycled paper, cardboard, and other paper materials. Since it doesn’t contain oxygen, it’s highly resistant to fires.
However, it can trigger newspaper dust allergies. Moreover, finding skilled individuals to install this insulation is relatively difficult.
Aerogel and cellulose are almost the same when it comes to their fire resistance and eco-friendly properties, but aerogel is much easier to handle and install.
While aerogel is a good option for insulation, you need to keep its drawbacks in mind to make a fair and reasonable decision.