How Radiant Barrier Works in a Metal Building
What is radiant barrier?
Radiant barrier is a material that reflects radiant heat transfer. Radiant heat transfer exists in our world in many ways, but primarily people understand the examples of radiant heat from the sun and from heat sources like fire.
Radiant heat is different from conductive heat because it travels through (or across) air until it is either absorbed by an object or it is either absorbed by an object or it's reflected from an object. Here's a simple example: the sun radiates heat toward the earth. The heat from the sun travels through our atmosphere and down toward earth. The sunlight warms buildings, cars, roads, people, etc. This heat from the sun continues while the sun is up and the heat is absorbed into the object. So if you're doing yard work on a sunny day, even if the air temp outside is cool, you can work up a sweat because of the sun's radiant heat absorbing into your skin. What about when a cloud passes over? You notice it, right?
The cloud shades us from the sun's radiant heat and we can feel that difference.
In essence, BlueTex™ insulation is like a shade for your metal building! Just like sitting in an outdoor stadium is unbearably hot on a sunny day, but tolerable on a cloudy one, radiant barrier makes a hot building more tolerable because it reflects the infrared energy (heat) emitting from the sun away from the building. What’s unique is the radiant heat can be reflected from INSIDE the building.
BlueTex™ has a pure aluminum layer that is a great solution to reduce heat flow through roofs and external walls by reflecting 97% of the radiant heat.
What about in winter? Good news! As long as you have a source of radiant heat inside the building (typically radiant heaters or wood-burning stoves), radiant barrier will help stop the heat from transferring through the foil layer to the other side. So in winter this means your BlueTex™ also helps hold heat inside your building.
Radiant Heat vs. Conductive Heat
Radiant heat (the process of heat transfer through air/space with no contact) and conductive heat transfer (the process of heat transfer through direct contact between materials/objects), both play significant roles in a warehouse or metal building environment.
It’s important to recognize that any structure is exposed to both radiant and conductive heat gain, so depending on how you’re using the building, you should consider which one is best suited to your application.
Traditional insulation, with its R-value, effectively slows down conductive heat. R-value simply quantifies how effectively an item or material inhibits heat gain. But in a building that’s not being heated and cooled, would you rather block heat or slow it down? Conductive heat is slowed by traditional insulation with R-value. R-value is simply a measure of how well an item (or material) slows down conductive heat gain.
A radiant barrier isn’t measured with r-value because it doesn’t just slow down heat, it prevents radiant heat from passing through it.
Blocking heat from coming inside in the first place is the most effective way make the building comfortable and easier to cool down quickly, especially if you have an A/C unit that you only run on an occasional as-needed basis.
In a truly non-conditioned building, a radiant barrier alone can sufficiently block heat from entering or escaping so no r-value is needed. For this reason, a radiant barrier is the best choice for semi-conditioned and non-conditioned buildings.
How Radiant Barrier Works in Your Building
What makes radiant barrier foil exceptionally effective in cooling down a hot warehouse or garage is its ability to block 97% of radiant heat. When it does this, it prevents that heat from being absorbed into spaces such as garages, barns, and warehouses, thereby fostering a more comfortable and energy-efficient environment.
To illustrate, imagine holding a hot brick a few inches away from your arm; you can distinctly sense the radiant heat emanating from it. However, when the brick is pressed against your skin, the heat transferred becomes conductive, as both objects are in direct contact.
Radiant heat, being part of the light spectrum, travels at the speed of light until it is either absorbed or reflected.
You can block radiant heat with a radiant barrier, which is made of a highly reflective sheet of pure polished aluminum foil, laminated to a heavyweight, tear-resistant internal woven scrim.
Functioning virtually the same as a tear-resistant tarp, the product is tough enough to be pulled and stapled/screwed into inside a metal building. Meanwhile, that aluminum surface reflects over 97% of the radiant heat coming toward it. Now, when BlueTex™ is placed between the individual and the hot roof or walls, the highly reflective surface of the radiant barrier foil redirects the heat outward, away from the contents inside the building, thereby maintaining a cooler environment inside the building.
BlueTex™ Compared to Bubble Foil & Other Similar Products
A common question we hear is: How does BlueTex™ radiant barrier compare to other metal building insulation products, like Bubble Foil insulation? Find out the answer to this popular question here.
The main differences are in how BlueTex™ is made versus how Bubble Foil is made. Bubble Foil products are mostly made of plastic and aren't near as strong and durable as BlueTex™ insulation. BlueTex™ is made from pure aluminum and dense foam, creating a tear proof and puncture-resistant, UV protected layer that blocks radiant heat, stops air transfer and protects against condensation. Additionally, unlike Bubble Foil products, BlueTex™ is backed by 20-year warranty and won't break down over time.
Other Common Questions
How do I attach BlueTex™ to the metal frame? Does there have to be an air space? Will BlueTex™ stop moisture? How much does BlueTex™ cost? Answers to all of these questions and more can be found in our Frequently Asked Questions here.