The race to the best thermal conductivity

logo_smallNot so long ago, a thermal conductivity of 0.025 W/mK was considered as very good. But today, it is possible to buy 0.005 W/mK and it seems that the market is interested.
This super insulation, called VIP, is very fragile because it is in fact a moderate vacuum bag, filled with a nano porous material. A little damaging and the thermal conductivity increases to 0.025 W/mK. Changing dimensions is not possible due to the vacuum and also the life time is limited due to the thin bag, which allows always a certain diffusion.

I was teached that the market is always right but marketing is a strong weapon which is able to put the market on the wrong leg. Is the market stupid? Windows makes a lot of money with the WINDOWS operating system and OFFICE suite while LINUX and LIBRE OFFICE are free of charge. Free of charge Android was able to pass IOS but GOOGLE has a strong marketing machine. It seems that only strong marketing is able to let happen what is logic.

In the building industry, Ytong (Xella) was the first building material which was insulating and load bearing. With a thermal conductivity of 0.090 W/mK and U= 0.15 W/(m²K), we get walls of minimum 60 cm thickness for passive housing. The price is typically 96€/m³ or 58€/m². The same job can be done with cellular glass GLAPOR PG900.2 (0.055 W/mK) boards up to 3×1.5m at 73€/m². The last one has as bonus water- and vapor tightness. For comparison, VIP-insulation has a cost of 224€/m² for the same U-value, while VIP-insulation is totally not load bearing.

For a 1 stock house of 200 m² in 10 x 10 m, we arrive at 500m² or 40000€ for the construction materials (GLAPOR) in case we use an intelligent shape. Better insulating materials without load bearing capacity need extra construction materials. A the end, the construction is much more expensive if the market joins the race of the best thermal insulators. Efficient marketing needs to promote the use of load bearing thermal insulation for the building industry. With large GLAPOR boards, passive house construction can be done at very sharp prices.

For the building industry, I believe that the race for the best thermal conductivity is like an F1-race. At the end of the race, you are back at start, there is not any evolution. The race for the best thermal conductivity is a useless race for the building industry.



3 thoughts on “The race to the best thermal conductivity

  1. Pingback: Natural convection in the (Belgian) double wall | BELGLAS BVBA

  2. Pingback: Dynamic thermal insulation with cellular glass | BELGLAS BVBA

  3. Pingback: Recycled glass is pure gold | BELGLAS BVBA

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