The R value of reflective thin insulation

Judging reflective thin insulation: looking past thermal resistance

Should reflective thin insulation be judged on its thermal resistance?

What is the R value of thin insulation?

Do not judge a fish by its ability to climb a tree

As Albert Einstein put it, everybody is a genius, but if you judge a fish by its ability to climb a tree, it will live its whole life believing it is stupid. The remark fits reflective thin insulation rather well. These products are regularly dismissed against conventional insulation on the strength of their low thermal resistance alone.

Thermal resistance is not the whole story

Videos and websites criticise reflective thin insulation on the grounds that its thermal resistance is very low. It is worth remembering that the thermal resistance calculation depends on thickness. The thicker the product, the higher the figure.

An insulation specialist weighs several criteria

Judging reflective thin insulation on thermal resistance alone is therefore misleading. A genuine insulation specialist weighs several criteria to assess how a product performs, among them:

• Reflection of thermal radiation
• The ability to prevent heat loss by radiation
• Resistance to water vapour diffusion
• Ease of installation
• Acoustic performance

Anyone who focuses on thermal resistance alone is leaving out much of what decides the outcome on site. A complete and honest assessment is a better basis for choosing the right product for a given job.