What is the approximate R value of one inch of fiberglass insulation?

The approximate R-value of one inch of fiberglass insulation is indeed around 3. R-value is a measure of thermal resistance, indicating how well an insulating material resists heat flow. The higher the R-value, the better the insulation's effectiveness. Fiberglass insulation is widely used in residential and commercial applications due to its favorable R-value, which generally ranges from 2.9 to 4.3 per inch, depending on various factors like density and type. The figure of 3 serves as a good average for many types of fiberglass batts and rolls.

Understanding the R-value is critical for determining how much insulation is needed to meet energy efficiency standards and ensure comfortable building temperatures. The R-value affects heating and cooling costs, making it an essential concept in HVAC design and installation. Additionally, when planning insulation, it’s important to consider local building codes and climate conditions, which may recommend higher R-values for particular areas.