How can ICF have an R Value of 50?
A. To begin with, think of when the weather man tells you the outside air temp is 30 degrees, but taking the wind in to count the wind chill is 0. Although it is still 30 degrees, it feels like 0 with no wind. Now think about how an ICF wall is made. The R in R Value means the resistance to heat flow. The three main ingredients of energy efficiency is infiltration of air, insulation, and thermal mass. The density of ICF foam when combined with concrete, will not allow air to pass through. The ICF foam is an excellent insulation, especially when compared to fiber glass insulation. Although concrete itself it not a good insulation, it is a good thermal mass source, maintaining a constant temperature when encased by the ICF form. So, knowing this and thinking about wind chill, it is easy to see how an ICF wall can be considered R-50 plus.
