When it comes to choosing or making your own window shades for your van, Reflectix is often recommended. But is Reflectix truly the best? After making comparisons, we choose XPE foam covered with double-sided aluminum foil for our VannCamp window covers. Why do we prefer the XPE? This article will explain our reasoning.
Getting to Know Reflectix and XPE
What is Reflectix?
Reflectix is a reflective insulation product made from polyethylene bubble wrap sandwiched between two layers of aluminum foil. It’s designed to reflect radiant heat.
Insulation Mechanism: Primarily insulates by reflecting radiant heat. The aluminum foil reflects up to 97% of radiant heat, while the bubble layer provides some resistance to conductive heat transfer.
What is XPE covered with double-sided aluminum foil?
First, let’s introduce XPE. XPE, or cross-linked polyethylene foam, is a type of polyethylene foam that has undergone a cross-linking process, which enhances its properties compared to regular polyethylene foam. XPE foam is characterized by its closed-cell structure, making it highly durable, water-resistant, and thermally insulating.
As the name suggests, XPE with double-sided aluminum foil is XPE covered with a layer of aluminum foil on both sides.
Insulation Mechanism: Provides thermal resistance through its foam structure and reflects radiant heat via the aluminum foil.
Insulation Performance of Reflectix and XPE
Thermal insulation performance is primarily associated with two properties: heat conduction and heat reflection.
Heat conduction
First, let’s take a brief look at the basics of heat transfer.
Heat conduction is the process by which heat energy is transmitted through collisions between neighboring atoms or molecules. In this process, heat flows from the higher temperature region to the lower temperature region. The rate of heat conduction depends on the temperature gradient, the properties of the material (such as thermal conductivity), and the cross-sectional area and length of the material through which heat is being transferred.
For a fair comparison, we base it on the assumption that both materials are subjected to the same temperature gradient and have identical cross-sectional area and length. It is evident that the thermal conductivity is the remaining point of difference.
The main factors affecting a material’s thermal conductivity are its material composition (chemical elements and compounds), material structure (crystal structure and density), and the phase of the material (solid, liquid, or gas).
In terms of material composition, XPE is similar to the Polyethylene Bubbles in Reflectix, both composed of ethylene molecules (CH2=CH2) and air.
In terms of material structure, XPE and Reflectix primarily achieve insulation by hindering air conduction. Since XPE features a multitude of closed-cell structures, further impeding air convection between the internal pores, leading to superior insulation performance. Conversely, the air bubbles in Polyethylene Bubbles are significantly larger, allowing for more air convection, resulting in inferior insulation compared to XPE.
Heat Reflection
Both use double-sided aluminum foil, in this respect, they are similar.
Therefore, in terms of insulation performance, XPE has a slight edge.
In addition to insulation performance, we also focus on other aspects, such as sound insulation and durability.
Noise reduction capabilities of Reflectix and XPE
The reduction of sound is related to two aspects: absorption and sound insulation. That’s right, sound absorption and sound isolation are two different concepts.
Sound absorption is the process by which sound waves are reduced in intensity as they encounter an absorptive material. When sound passes through a material, some of the sound energy is converted into other forms of energy, such as heat, vibration, or motion, causing the sound to become quieter or less noticeable. Absorbent materials typically have a porous structure.
Sound isolation, also known as soundproofing, is the process of reducing the transmission of sound waves through a material or structure. It aims to prevent sound from entering or exiting a space, creating a quieter and more controlled acoustic environment. Soundproofing materials typically have a high density.
Compared to Reflectix, XPE is a porous material with air pockets that can trap and absorb sound waves, reducing their intensity and reverberation. This is particularly effective for higher frequency sounds. Meanwhile, XPE has a much higher density than Reflectix. its dense and closed-cell structure can dampen vibrations and reduce both airborne and impact noise.
Durability of Reflectix and XPE
Due to its three-dimensional network structure from cross-linked polyethylene foam, XPE boasts superior strength and durability.
Reflectix is also quite durable, but it is still not as stable as XPE.
Conclusion
XPE with double-sided aluminum foil surpasses Reflectix in terms of insulation and heat resistance, while also offering additional soundproofing and superior durability. Therefore, we opt for the former as the insulation material for our van window covers.