
How fiberglass insulation works
Fiberglass insulation is designed to be fluffy and take up as much of a framing cavity as possible. Fiberglass insulation is also designed to be encapsulated, which means covered on all sides, like a box. For maximum efficiency of fiberglass insulation, the encapsulation should be sealed not allowing air movement. But here is the confusing part. The woven fibers that make up fiberglass is not an insulation material. The layers of woven fiberglass create air pockets that are designed to trap the air inside the framing cavities and prevent thermal changes from occurring. While most people accept this explanation, there are some major problems with this scientific explanation:
Problem 1: There is no such thing as an air tight framing cavity. Air movement is imminent unless closed cell ...