UNDERSTANDING R AND U VALUES IN THERMAL INSULATION

WHY U-VALUE MATTERS.

When selecting the right insulation system for your construction project, understanding the difference between R and U values & knowing you have a choice to meet code using either value, is critical. These values are key indicators of thermal performance, but they measure different aspects of insulation effectiveness.

U-VALUE: A COMPREHENSIVE MEASURE.

U-value measures the rate of heat transfer through a system, taking into account the entire assembly, including insulation, framing, and other materials used. Unlike the R-value, a lower U-value indicates better insulation performance.

The U-value is a superior metric for measuring insulation systems because it accounts for real-world factors such as thermal bridging, which can significantly impact the effectiveness of your insulation. (The table above C402.1.4, taken from IECC 2021, displays where/how the IECC communicates the U-Factor method’s requirements for meeting the code.)

R-VALUE: THE BASICS.

The R-value measures an insulation material’s resistance to heat flow. The higher the R-value, the better the material insulates. This measurement is essential in determining how well an insulation material can keep heat from escaping or entering a building. For instance, if you have an R-30 insulation, it provides greater resistance to heat flow than an R-15 insulation. (The below Table C402.1.3, taken from IECC 2021, displays where/how the IECC communicates the R-Value method’s requirements for meeting the code)

Why U-Value Matters More.

While R-values are useful for understanding the properties of individual insulation materials, U-values provide a more comprehensive picture of a building’s overall thermal performance. Here’s why you should prioritize U-values when choosing an insulation system:

  • Holistic Assessment: U-values consider the entire assembly, not just the insulation material. This includes potential heat loss through framing members and other components that can compromise insulation effectiveness.
  • Real-World Performance: Construction projects often face issues like thermal bridging, where heat bypasses the insulation through conductive materials like metal girts and purlins. U-values account for these heat transfer paths, providing a more accurate representation of the building’s thermal performance.
  • Energy Efficiency: Lower U-values translate to better overall energy efficiency, reducing heating and cooling costs over the building’s lifetime.

Beyond Envelope Continuous Insulation: The Superior Choice For Maximizing U-Values.

When it comes to maximizing energy efficiency and thermal performance, selecting a comprehensive beyond envelope insulation system is essential. Unlike traditional faced fiberglass liner systems that often get compressed at girt and purlin supports, a beyond envelope continuous system, such as R-Seal®, ensures consistent insulation coverage without gaps or compression.

Key Benefits.

  • Eliminates Thermal Bridging: Continuous insulation covers the entire building envelope, minimizing thermal bridges and  nsuring more uniform thermal protection.
  • Consistent Performance: Our system maintains its integrity and insulation value across all areas, unlike faced fiberglass liners that can lose effectiveness when compressed.
  • Enhanced Comfort and Savings: Better thermal performancemeans improved indoor comfort and significant savings on energy bills.

Investing in a continuous insulation system, with a focus on U-values, ensures your construction project achieves optimal thermal performance, energy efficiency, and long-term savings.

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