The Difference between Thermal and Acoustic Insulation

To insulate yourself from something is to isolate or protect yourself from an outside element, typically using some sort of material. However, depending on what you’re trying to insulate yourself from, the materials in use may look vastly different from case to case. Mankind has been trying to insulate themselves against the elements for all of recorded history, with different cultures discovering thermal insulation completely independent of each other.

However, a more modern issue that plagues the populace—particularly in more urban societies—is noise. Noise pollution is a major problem in inner cities as well as near aviation hubs such as airports or military bases. Acoustic insulation has gone up in demand as a result, and with the current shift towards independent content creation, more individuals are looking for ways to soundproof their homes—or at least one room.

So, with all this said, how do thermal and acoustic insulation differ? Moreover, is there any overlap?

Thermal Insulation
Thermal insulation is the most immediately recognizable to most Americans. It exists in most homes in some form or fashion, usually in the attics or hidden beneath the walls. Thermal insulation provides a straightforward purpose: keep the temperature inside the home from going up or down as much as possible. It provides a barrier preventing the transfer of heat either into the house from outdoors or out of the house from indoors. A well-insulated home can save a homeowner thousands on their electric or gas bills since their HVAC systems don’t need to work overtime in order to keep the interior at a stable temperature.

Seeing as it’s been around since the dawn of civilization, thermal insulation can take on many different forms depending on the region and time period.

Fiberglass
Invented in the 1930s, fiberglass remains the most prolific type of insulation in American homes. It usually appears as a dense pink fluff, akin in appearance to cotton candy. Fiberglass is able to decrease heat transfer due to the way it is created, which involves weaving thin strands of glass into a dense layer. This makes it not only a very effective insulator, but also resistant to flame.
The biggest disadvantage of fiberglass insulation is the potential for injury when handling it. Glass powder and tiny shards of glass are created as a byproduct since fiberglass is composed of tightly-woven silicon. If one tries to install or interact with this material unguarded, these invisible shards might cause damage to the eyes, lungs, and even the skin. However, if the right safety equipment is utilized, the installation of fiberglass insulation can be completed safely.

Spray Foam
Adapted for home use in the 80s, spray foam insulation is a slightly more modern take on thermal insulation. It comes in high, medium, and low densities, all of which have different parts to play when fully insulating a home. All densities have one thing in common, though: they’re able to fit into minute cracks and crevices. This makes foam more effective than fiberglass by default since it can cover a larger possible number of air leaks. As a general rule, the less air that’s allowed in, the more insulated your home will be.

Spray foam is what’s most commonly used in new construction and is constantly being innovated. Recently, some spray foam was made incorporating aerogel, giving it a 20% reduction in thermal conductivity. Aerogel itself is also an incredible insulator, though it isn’t commonly used outside of major organizations due to cost concerns. Notably, aerogel often sees use in NASA.

A Note on Asbestos
“If you or a loved one have been diagnosed with mesothelioma”, how many times have you heard those words echoed on TV? It’s no secret that many homes in America were unsafely insulated with materials containing asbestos before the harmful effects of the substance were brought to light, but it’s important to note what asbestos is. Asbestos is a naturally occurring mineral that is made up of flexible fibers that are heat, electrical, and corrosion-resistant. These characteristics make the mineral extremely beneficial as an insulator. Asbestos exposure, on the other hand, is extremely harmful and can cause a litany of different lung diseases.
If you buy an older home, be sure to check the type of insulation it uses while performing your home inspection. If the material in use contains asbestos, do not move in until it is removed safely.

Acoustic Insulation
Acoustic insulation is somewhat different in that, though thermal insulation can help control noise, you don’t need to douse your entire room in spray foam in order to control noise. While sound is the movement of atoms and molecules in rapid waving patterns. Heat is the completely random movement of atoms and molecules. Sound can be controlled far more effectively than heat in this sense, and soundproofing often looks far different than weatherproofing.

Shapes and Sizes
Acoustic insulation is usually either made of mineral foam or wool, similar to the spray foam and fiberglass of thermal insulation. However, stepping into the world’s quietest room, it will look a lot different than the most thermally insulated room. In Microsoft’s headquarters in Redmond, Washington, you can visit the quietest room, and you’ll quickly note that every surface is covered in tall, concrete, pyramid-esque structures. These structures create what’s known as an anechoic chamber, and the decibel levels within dip into the negative 20s. At that level of quiet, you can hear your blood pumping and your bones grinding.

In recording studios, similar materials are used—acoustic foam is often installed in large pyramid shapes or in elongated pyramid-esque slats. Though, these may be considered sound-absorbing rather than sound-insulating. If you want true, by the book, acoustic insulation installed in your home, tightly-compressed mineral wool and fiberglass boards are often used in walls to keep sound from being relayed to other parts of the building.

No matter your insulation needs, we at Smartech have you covered. From thermal to acoustic, we have a wide range of insulators to suit any project.