is there a formula to measure the difference between fiberglass insulation and spray polyurethane foam?

Question by orlando z: is there a formula to measure the difference between fiberglass insulation and spray polyurethane foam? (ie) a home 20′x20′ with 8′ sidewalls 1 door 3′x6′ and 4 windows 2′x3′ with an envelope of fiberglass verse’s foam what would be the energy savings per year per product? Best answer: Answer by jedThe difference between these two products will depend on their U-values. First you need to know the thermal conductivity of each material. Then you need to determine also the thicknesses of each material. Then you will get the thermal resistance of each material by dividing the… Read more about is there a formula to measure the difference between fiberglass insulation and spray polyurethane foam? →