This post is about an old substance which was recently discovered for insulation purposes, Aerogel.
This material is a cavernous, very light and solid material, which even can be transparent. It was invented in 1931, but the first industrial use was made in 1974 for a detector of radiation. Aerogel can be found in the Guiness Book of Records with several entries, because of its low density and best insulator.
Aerogel is dry gel. Here small pores have come into existence within the drying process. These pores are very small. Here the diameter is around 20-40nm, while in other materials normally the pores are bigger (60-80nm).
This is the main reason for the great heat insulation of this compound as there is no space for heat convection. In addition heat conduction within the material is very low as the air molecules cannot transfer the energy to the molecules of the Aerogel and the air trapped inside this material.
For the last possible method of heat transfer, the radiation, it depends on the source and the kind of wavelengths. But as this material has great adsorption and reflection values this way of heat transfer is negligible.
This material is already in use. For example polycarbonate and glass will be filled with this Aerogel. Naturally the transparent form is used here. Therefore it can be used for increasing the share of windows in buildings. The advantage of this is that fewer electric lights have to be installed as the day light is used more efficiently while the heat loss is reduced to a minimum due to the good insulation abilities of Aerogels.
This technology was used recently in Norway to construct an energy efficient grocery store. The store is meant to use 30% less energy than normal stores. One reason is the use of this Aerogel for the roof and transparent walls. In addition a system for shading off the sun did not need to be installed here because of this compound.
Furthermore there is a highly efficient heating and cooling system in place. The surplus heat from the cooling facilities is used and stored. There is a control system in place, which monitors the energy consumption of the store. It has to be emphasized that it is only one single system. Therefore no conflicts can occur between more systems.
All of the refrigerants (working fluids which transfer the heat) are environmentally friendly, because of the usage of CO2,, Butane and Propane. It has some more great features, for example the surplus of heat is so much that it is used to melt the ice in front of the shop. Therefore there is no slippery surface in winter times and it is likely that fewer accidents occur.
Aerogels are used in Aerospace already for a longer time. But research & development are going in the direction to make this technology available for the public. With all of this potential this technology should be made more known in the world.