General tab on Materials Dialog.
Materials are used to define the properties of construction layers. There are 2 types of material:
This field is used to enter the thermal conductivity of the material layer. Thermal conductivity must be greater than zero.
This field represents the specific heat of the material layer. Only positive values of specific heat are allowed.
This field is used to enter the density of the material layer. Density must be a positive quantity.
This field is used to enter the thermal resistance (R-value) of the material layer.
Note: Materials defined using an R-value do not contribute to construction (and hence building) thermal mass in the calculations and so should be used with care, especially if you plan to use the model for dynamic thermal simulations.