Thermal Resistance Calculator
Calculate thermal resistance (R-value) of a material layer: R = d / k.
Thermal Resistance
2.5000 m²·K/W
Thermal Resistance vs Material Thickness
Formula
## Thermal Resistance Thermal resistance quantifies how well a material layer resists heat flow. ### Formula **R = d / k** where d is thickness and k is thermal conductivity. Higher R means better insulation. For multiple layers, R-values add in series.
Exemplo Resolvido
10 cm of fiberglass insulation (k = 0.04 W/(m·K)).
- 01R = d / k
- 02R = 0.1 / 0.04
- 03R = 2.5 m²·K/W
Perguntas Frequentes
How do R-values add up?
For layers in series (like wall construction), R-values add directly: R_total = R1 + R2 + R3. This is similar to resistors in series.
What does R-value mean on insulation packaging?
It indicates thermal resistance per unit area. Higher R-value means better insulation. R-19 is typical for walls; R-38 to R-60 for attics.
What is the difference between R-value and U-value?
U-value is the reciprocal of R-value (U = 1/R). Lower U-value means better insulation. U-value is commonly used in building codes outside North America.
Aprender