Dust Accumulation Ruins Radiant Barrier

If a radiant barrier is on the ground, then dust can land thereon and over time won’t that cover the foil and make it useless? Why would you suggest anyone install the foil over the insulation if this is often true?

Myth: the buildup of dust on radiant barrier compromises it’s reflectivity and thus its ability to figure as a reflector of radiant heat.

To begin, it’s truthful to mention that the majority homes won't accumulate enough dust within the attic area to diminish aluminum’s reflective quality. Even at a look, a skinny layer of dust on your AtticFoil™ radiant barrier has been shown to cause no difference within the ability of the fabric to reflect radiant heat. An easy thanks to consider this is often to think about a mirror in your home which may get dusty; the more dust that accumulates, the more reflectivity the mirror will lose.

Dust and Single-Sided Foil

Before double-sided foil was created, radiant barrier existed as a single-sided product. due to this, installation was precise during which side of the foil needed to confront or down. About 30 years ago, when single-sided foil still dominated the market, most installations consisted of laying the foil on the attic floor, over the prevailing insulation. The foil was installed with the foil side facing up, leaving it susceptible to dust collection. In cases where dust accumulated rapidly and regularly, it had been noted that this had an impression on the reflectivity of the radiant barrier. Large amounts of dust can reduce, or eliminate, aluminum’s ability to act as a reflector of radiant heat.

Therefore, it had been determined that when employing a single-sided product, careful measures had to be taken so as to attenuate dust accrual. a number of these measures included stapling the foil abreast of the rafters and using multiple layers of foil on the ground, but eventually the superior idea of making a double-sided material was born.

Dust and Double-Sided Foil

The creation of a double-sided radiant barrier proved to be cheap thanks to increased year-round benefits, while eliminating the threat of dust endangering the reflectivity of the foil’s surface. The most advantages of double-sided heavyweight radiant barrier foil are that it allows for cover against radiant heat by one among two ways: reflectivity or emissivity. Both properties are present within the foil, so if/when one is compromised, the foil can still get rid of the opposite property, without a decrease in overall performance.

Reflectivity and Emissivity

Reflectivity is defined as a measure of the power of a surface to reflect radiation (or energy/heat). Aluminum’s reflectivity is 97%; therefore, aluminum has the power to reflect 97% of the radiant heat waves coming in touch with it. This is often why AtticFoil™ radiant barrier works so well against radiant heat – when the sun radiates heat to the world , it's either absorbed or reflected. Typically your roof will absorb the warmth (because the bulk of roofs aren't reflective) and it'll travel through the roofing materials until it reaches your attic. At that time there's nothing left to return in touch with therefore the heat converts from traveling conductively (through materials that are touching within the roof) to its radiant form (heat traveling across an air space) where it can now be reflected (via the radiant barrier) back towards the direction it came from.

Emissivity is defined because the ability of a surface to emit (release) energy. While aluminum features a high reflectivity (97%), it's a coffee emissivity (only 3%). This suggests that aluminum only allows 3% of radiant heat to undergo it by means of trapping 97% of the radiant heat behind the foil.

Therefore, counting on which side of the double-sided product the air gap is one, the foil are going to be either using reflectivity to reflect heat or emissivity to dam it. Either way, your results are getting to be 97% rejection of warmth transfer.

Dealing with Dust

So what do reflectivity and emissivity need to do with dust and the way it affects foil? Where previously foil had one side, optimal conditions were required so as to form sure the topside wouldn't be compromised by dust accrual. Now, with double-sided foil, albeit the dust does get to some extent where it jeopardizes the

reflectivity, the foil on rock bottom side (the side facing the insulation on the floor) will get rid of it’s emissivity quality, only allowing 3% of the warmth to undergo.

If it’s wintertime and you’re heating your home, this suggests you’re not losing heat through the roof then your home stays warmer without using the maximum amount energy (to replace what's being constantly lost). If it’s summertime, this suggests only 3% of the radiant heat entering your attic are going to be emitted into the insulation on your floor. So instead of absorbing 100% of the warmth and having to run your air conditioning to stay your lebensraum cool, you now only need to affect about 3% of that heat. meaning a cooler, easier home and a more reasonable energy bill. Overall double-sided foil is that the most suitable option for all applications of a radiant barrier because it offers you the advantage of both of aluminum’s properties, making dust a non-issue.