Number of Nodes Conduction Finite difference

I used CFD for simulation of two different wall materials. Both are thermal mass. For one material, even with less thickness; number of nodes is more than the other material. Could this be related to the thermal properties such as conductivity? Let's say the wall material with less conductivity results in more nodes? In brief, would like to know how the number of nodes is chosen in CFD? If there is any reference about this that I could get more info about this, I would appreciate someone could introduce.

You should be able to find more information regarding the number of node calculation in the Engineering Reference. The following is an excerpt from the engineering reference, please refer to the link above for full context.

The discretization method allows CondFD to assign different node spacing or grid size to different material layers in a wall or roof, as building walls and roofs typically consist of several layers of different materials having different thermal properties.
Δx =√(CαΔt)
The actual integer number of nodes for each layer is then calculated by rounding off the result from dividing the length of the material layer by the result of the equation above.