How can radiant barriers be installed in an attic?

Radiant barriers are designed to reduce heat transfer via radiation, and installing them effectively can significantly influence the thermal performance of an attic space. The correct method involves hanging radiant barriers from the rafters or laying them on top of ceiling joists.

This installation method works because it allows the radiant barrier to create an airspace that enhances its ability to reflect heat away from the living space below. When the barrier is positioned in this manner, it effectively reflects radiant energy away from the attic, preventing it from warming the insulation and, consequently, the living areas of the house. This is particularly beneficial in hot climates, where reducing heat gain is often a primary goal for energy efficiency.

Positioning the radiant barrier in other ways, such as on the ceiling below the attic, within insulation, or solely on the roof surface, would not harness the full potential of the barrier's reflective qualities. For instance, placing it directly on the roof surface may not be as effective because it doesn't create the necessary air gap to maximize radiation reflection. Moreover, embedding it within insulation can obstruct its reflective capability, losing the intended benefits of reducing heat transfer.