Radiant barriers and reflective foil insulation are proven to lower your energy cost. As their use continues to climb, it is important that consumers understand the difference between the various products. Unfortunately the wide variety of industry products available can be confusing. This article is to clarify the differences between attic radiant barriers and reflective foil insulation.
Maybe, the confusion is that all reflective foil insulation is a radiant barrier. That is its purpose, to reflect the transfer of radiant heat. With that said, here is the differences and nomenclature needed to understand and speak about foil insulation intelligently.
Radiant barriers, or more specifically radiant barriers designed for attics are a two or three ply membrane consisting of foil/polyethylene or foil/polyethylene/foil respectively.
Foil, No-Tear Weave, Foil
This is an industrial layer of aluminum material bonded with a polyethylene fabric to create a reflective surface that is both extremely tough and resilient. It is marketed, as its name implies, as an attic radiant barrier product and should be the only used in attics.
Reflective foil insulation on the other hand is still a radiant barrier but it is designed differently, and for different applications. Bubble foil, as it is commonly called, is a single or double layer of ultra strong polyethylene bubbles sandwiched between two layers of reflective foil.
Foil, Double Bubble, Foil
These products should be the only ones used in under slab or around slab applications, wrapping ductwork, or insulating crawlspaces.
Please see the different areas of a home or building and which product should be used:
Radiant Barriers:
- Attics
- House-wraps
- All vapor barrier applications
- Ceilings
- Side Walls
Reflective Foil or Bubble Foil Insulation:
- Flooring or Radiant Heat
- Ductwork
- Crawlspace
- Pipe wrap
- Basement Wall
- Under Slab
- Ceilings
- Side Walls
Note: Most attic applications require a perforated product to allow moisture transfer. Double check your application before applying any solid product that could act as a vapor barrier.
Reflective foil insulation can also be configured in a bubble/foil/bubble design for concrete applications or in a foil/bubble/poly (white) configuration designed for metal buildings, commercial applications, or agricultural buildings.
