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Radiant Barrier

How Radiant Barriers Work

A radiant barrier reflects or blocks radiant heat energy instead of trying to absorb it.   A radiant barrier can also reduce convective heat transfer by acting as a physical blockade against convective air flow.

Radiant Barrier Diagrahm Key Energy Solutions

How does a radiant barrier reflect/BLOCK radiant heat?


 

The reflective surface of radiant barriers has two properties that enable it to reflect or block radiant heat when at least one air space is provided on one side:

  1. Reflectivity = The natural reflectivity property of a reflective surface facing a heat source across an air space allows the aluminum to reflect radiant heat back to the direction from which it came.
  2. Emissivity = All materials have emissivity's ranging from 0% to 100%.  The lower the emittance percentage of a material, the lower the amount of radiant heat radiated from its surface.  The naturally low emissivity property of a reflective surface facing an air space results in very low emittance of heat from itself; it does not radiate much of its own heat from itself.

A Radiant barrier reflects radiant heat that strikes its surface across an air space from a heat source and conversely, it emits very little radiant heat from its surface across an air space opposite a heat source.