Open and Closed Cell Insulation Boards from Kingspan

Open versus closed cell phenolic foams

When comparing different rigid phenolic insulation boards, it is important to distinguish between 'Open Cell' and 'Closed Cell' designs, as their respective performance characteristics vary widely.

Kingspan Insulation's Kooltherm® insulation boards are made using Closed Cell phenolic foam for the following reasons.

Open Cell insulation foam, as the name implies, permits the blowing agent to quickly disperse and enables transfer of air or water vapour through an 'open' or 'porous' interconnected material structure, just like a sponge. This is why only an aged R-value is a true representation of its performance and not the value achieved immediately after manufacture. The degree of movement through the body of the material is dependent on a range of factors, including the size and density of the cells, moisture ingress, as well as the chemical composition of the material itself.

The salient point is that porous, sponge-like characteristics are not ideal features of insulation. Quite simply, any flow through an insulating material is defeating its purpose as it facilitates unwanted energy transference.

By contrast, Closed Cell materials feature millions of unconnected cell pockets, which effectively contain the blowing agent long term.