Best Radiant Barrier Placement Location In An Attic

So you've decided that you want to use a radiant barrier product in your attic but you aren't sure where it should be installed? In a retro-fit installation project, a radiant barrier is typically installed in one of two locations:

• rolled out over the attic floor with or without existing insulation already in place, OR
• stapled to the underside of the roof rafters.

Which is the best location that yeilds the highest savings? There are several factors to consider:

1. The Reflective Insulation Manufacturers Association (RIMA) conducted a study on the placement of radiant barriers between the two locations and found that the placement on the attic floor yeilded the highest benefits.
2. Opponents to placing a radiant barrier on the attic floor have the following concerns:

• dust accumulation can diminish the effectiveness of a radiant barrier over time - in response to this claim, Tennessee Valley Authority project engineer James R. Hall conducted a study on radiant barrier dust accumulation effects and found that dust accumulation had little to no affect on the performance of a radiant barrier on an attic floor placement.
• AC duct work suspended in an attic above a radiant barrier placed on the attic floor is continually subjected to radiant heat as if no barrier had been used therefore causing warm air to initially blow out the vents into livings spaces - in response to this claim, this can easily be overcome by laying an additional piece of radiant barrier over the duct work like a blanket.
• items stored in the attic on top of a radiant barrier placed on the floor render that section of the radiant barrier ineffective - in response to this claim, this can easily be overcome by laying an additional piece of radiant barrier over the storage items like a blanket.

Armed with the studies, claims, and responses above, we hope we have made it easier for you to decide what attic installation location is best for your application.