What is the primary function of the "R" factor in insulation?

The primary function of the "R" factor, or R-value, in insulation is to quantify the thermal resistance of the insulating material. It indicates how well the insulation can resist heat flow; the higher the R-value, the greater the insulation's effectiveness. This value is crucial for assessing the energy efficiency of buildings, as it helps determine how much energy is needed for heating or cooling.

While thickness can play a role in the overall R-value, the R-factor specifically measures thermal resistance rather than just material thickness. Therefore, it is a crucial metric for evaluating how well an insulating material can prevent heat transfer, thereby contributing to energy savings and greater energy efficiency in buildings. Other options, such as measuring cost or weight, do not accurately represent the primary function of the R-value in insulation.