What does the R-value in insulation indicate?

What does the R-value in insulation indicate?

• A. Indicates how well it can resist heat flow
• B. Indicates moisture resistance
• C. Indicates reflectivity
• D. Indicates acoustic absorption

Answer: (A)

R-value measures thermal resistance to heat flow. It tells you how well insulation slows the transfer of heat between indoors and outdoors—the higher the R-value, the more resistance to heat transfer and the better the insulation’s performance in keeping warmth in or out. It depends on both the material and its thickness: increasing thickness or choosing a material with lower thermal conductivity raises the R-value. In practice, you add the R-values of all layers in an assembly (and any surface air films) to get the overall resistance. The other properties—moisture resistance, reflectivity, and acoustic absorption—are different concerns and aren’t what the R-value measures.

R-value measures thermal resistance to heat flow. It tells you how well insulation slows the transfer of heat between indoors and outdoors—the higher the R-value, the more resistance to heat transfer and the better the insulation’s performance in keeping warmth in or out. It depends on both the material and its thickness: increasing thickness or choosing a material with lower thermal conductivity raises the R-value. In practice, you add the R-values of all layers in an assembly (and any surface air films) to get the overall resistance. The other properties—moisture resistance, reflectivity, and acoustic absorption—are different concerns and aren’t what the R-value measures.