R-Value

R-value is a  measure of a substance's resistance to heat flow. It measures a material’s ability to slow down or resist the transfer of heat energy, also called thermal resistance. The greater the R-value, the better the resistance, the better the insulation. R-values are the reciprocal of U-values.

While many in the building community consider R-value to be the primary indicator of energy efficiency, it only deals with conduction, one of three modes of heat flow: conduction, convection, and radiation and it is not particularly important in the Dallas-Fort Worth area.

R-value is a term predominantly used in the building industry to quantify the insulating properties of construction materials and building assemblies. Supposedly, the higher the R-value, the greater the insulation.

R-values do offer a useful means of comparing the performance of different products. However, R-value must be placed in it proper context as other factors are instrumental in maintaining thermal comfort--for example, 25% to 40% of a home's energy use can be attributed to air infiltration.  

Also, R-value is not particularly important in the Dallas-Fort Worth area.

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