It isn’t cars and vehicle traffic that produce the greatest volumes of climate gas emissions – it’s our own homes. But new research will soon be putting an end to all that! The building sector is currently responsible for 40% of global energy use and climate gas emissions. This is an under-communicated fact in a world where vehicle traffic and exhaust emissions get far more attention.
In the future, however, we will start to see construction materials and high-tech systems integrated into building shells that are specifically designed to remedy this situation. Such systems will be intelligent and multifunctional. They will consume less energy and generate lower levels of harmful climate gas emissions. With this objective in mind, researchers at SINTEF, a scientific institute located in Norway, are currently testing microscopic nanoparticles as insulation materials, applying voltages to window glass and facades as a means of saving energy, and developing solar cells that prevent the accumulation of snow and ice. SINTEF researcher Bente Gilbu Tilset is sitting in her office in Oslo. She and her colleagues are looking into the manufacture of super-insulation materials made up of microscopic nanospheres.
“Our aim is to create a low thermal conductivity construction material “, says Tilset. “When gas molecules collide, energy is transferred between them. If the pores in a given material are small enough, for example less than 100 nanometres in diameter, a molecule will collide more often with the pore walls than with other gas molecules. This will effectively reduce the thermal conductivity of the gas. So, the smaller the pores, the lower the conductivity of the gas“, she says.
While standard insulation materials such as mineral wools have conductivities in the region of 35 milliwatts per metre, nanospheres may exhibit values as low as about 20 mW/m. This is lower than the thermal conductivity of air. At present, these spheres are only available as a powder, but our dream is to aggregate them to form flexible mats.
In the future, nano-insulation materials such as these will enable us to reduce existing insulation material thicknesses. The mats will probably be more expensive than current products such as ‘Glava’, but will offer a better option in situations where space is at a premium such as in protected buildings where there are restrictions on making modifications to facades. They also work well as insulation materials for oil pipelines and industrial tanks.
Solar cells installed in panels fixed to our roofs and walls will be a thing of the past. Instead, they will be integrated into the roof tiles and external wall panelling materials. This will save on building materials and construction costs, and will reduce electricity bills.
“In spite of Norway’s long, dark, winter nights, we are exposed to just as much daylight as Germany or the UK. A colder climate is in fact an advantage because solar cells are more effective in the cold. We reckon that this will become part of the Norwegian building tradition“, says physicist and SINTEF researcher Tore Kolås. Researchers are planning to look into how we can utilise solar cells as integral housing construction components, and how they can be adapted to Norwegian daylight and climatic conditions.