Assertion: insulation's r value | /r/HasProperty | additive
Facets:
value: no longer
type: TEMPORAL
value: for layers of materials
type: PURPOSE
Source sentences:
text: R-values are additive for layers of materials, and the higher the R-value the better the performance.
text: As long as the materials involved are dense solids in direct mutual contact, R-values are additive; for example, the total R-value of a barrier composed of several layers of material is the sum of the R-values of the individual layers.
text: However, this generalization comes at a price because R-values that include non-conductive processes may no longer be additive and may have significant temperature dependence.