Radiant Barrier Journal

Almost every one familiar with insulation knows two basic things when it comes to R-Values:

1. An R-Value is a measurement of how effective a conventional insulation product is at reducing the transfer of heat, and
2. The higher the R-Value, the better when comparing products.

However, exactly what an R-Value measures alludes many people and therefore, causes confusion when discussing radiant barriers and how they reduce heat transfer.

Heat ALWAYS moves from a warm area to a cooler area and it does so using three different transfer methods:

1. conductive heat transfer – the transfer of heat through a substance or to another touching substance.
2. convective heat transfer – the transfer of heat through a fluid or gas such as heated air rising from a boiling pot of water.
3. radiant heat transfer – the transfer of heat across an air space (or vacuum).

Click here to read more…

FAQ:  Will adding a radiant barrier to my attic space make my roof hotter or harm my shingles?

ANSWER: A radiant barrier will increase the surface temperature of your roof between 2 to 5° F on a hot sunny day but it’s already between 160 to 190 degrees at that time so the difference is very negligible and shouldn’t adversely affect your shingles (per a 2002 study performed by the Florida Solar Energy Center).

Because a radiant barrier reflects radiant heat back toward the roof decking, this is a very common question.  As a result of the rise in use of radiant barriers, and an increase in this concern, a study performed by the Florida Solar Energy Center was conducted on radiant barriers and roofing materials in 2002.  Click here to read more…

FAQ:  Will a radiant barrier work when installed under my new asphalt shingles?
ANSWER:  No.   A radiant barrier MUST be facing an air space for it to reflect the radiant heat.  Without an air space on at least one side of a radiant barrier, radiant heat will conduct all the way through it as if not installed. Click here to read more…