Which wall configuration is better for insulating against heat conduction?

The choice of a wall with R-values of 10 and 3 is better for insulating against heat conduction because R-value is a measure of thermal resistance. The higher the R-value, the better the material is at resisting heat flow. In this case, the combined R-value of the two layers indicates a stronger overall effectiveness in reducing heat transfer.

When considering wall configurations, it's important to evaluate the total R-value achieved by layering materials. The configuration with R-values of 10 and 3 not only benefits from the substantial resistance to heat transfer provided by the layer with an R-value of 10, but it also adds to that resistance with the additional layer of R-value 3, resulting in a cumulative effect that enhances insulation against both heat loss in winter and heat gain in summer.

Walls with lower or multiple R-values, such as the one with values of 1, 11, and 0.5, do not provide sufficient insulation for effective heat retention or rejection because the lower R-value of 1 greatly diminishes the overall thermal performance. A single layer also lacks the cumulative resistance that multiple layers can achieve. Lastly, stating that R-value is irrelevant ignores the fundamental principle that adequate insulation is critical for energy efficiency, comfort, and climate