Let’s start with defining the two. Fiberglass insulation is used to slow down the loss or gain of heat within a home. It provides a barrier between the inside of the home and the significantly different temperatures outside of the home. Radiant barrier, or foil insulation, differs from fiberglass insulation in that, instead of slowing down the process of heat transfer, it blocks and reflects heat.
Great! Now we have a foundational understanding of how the two types of insulation work. So, which is better? Let’s talk a little about heat transfer first. Heat transfer occurs through 3 different processes: conduction, convection, and radiation. For more detailed information on these processes, see our previous blog, “The Difference Between Conduction, Convection and Radiation.” Fiberglass insulation offers protection from conductive and convective heat, but what about radiant heat? Fiberglass insulation only slows radiant heat gain. That’s where radiant barrier comes into play. Radiant barrier’s unique reflective properties prevent up to 97% of radiant heat gain by reflecting rather than absorbing the heat.
What does this mean for the consumer? Adding radiant barrier to your building increases the efficiency of indoor heating and cooling, meaning big savings on energy bills!
So, no, radiant barrier is not the same as insulation, though it is a type of insulation. Radiant barrier can work alongside other types of insulation to increase the efficiency in your home and add the missing component to protect your home from radiant heat.