Thermal properties of aerogels: From theory to practice

Abstract

Due to growing economies and populations, the world temperature has risen gradually. The increase in temperature reached about 0.8 within the last decades. Global warming is considered as one of the vital issues for not only human beings but also for all living beings. The increase in global warming is attributed to greenhouse gas emissions (GHGEs). According to the results from the latest researches, the increase in the surface temperature of the earth is to be in the range of 1.1 - 6.4°C depending on the lowest and highest emission scenario, respectively. For this reason, of oil equivalent in 1999 and in another study it is underlined that the buildings located in developing countries account for 35% of GHGEs (8.3 Gt CO2). When considering all above, the energyefficient buildings are vital for reducing energy demand. Wall insulation is of significant relevance to the overall performance of energy-efficient buildings. The research carried out in the UK points out the potential decline in GHGEs through proper wall insulation as 5.5%. Although conventional insulation materials improve energy efficiency of the building envelopes, the improvement is not at desired level in most cases when compared to superinsulation materials. Moreover, superinsulation materials are more attractive than the conventional ones in terms of several aspects, such as less energy consumption, providing more living space, and enabling aesthetic solutions. Aerogel, known as a typical superinsulation material, has a wide range of application areas, including main sectors such as buildings, automotive, electronics, and fabric sectors. When comparing thermal resistance of some conventional and superinsulation materials, it can be easily reached that the performance of aerogel is notably better than the others. Thermal conductivity of mineral wool, EPS, XPS, PUR and aerogels are in the range of 0.034 - 0.045, 0.029 - 0.055, 0.029 - 0.048, 0.020 - 0.029, and 0.012 - 0.020 W/mK, respectively. Aerogel also enhances indoor thermal performance of the residential buildings with slimmer structural details and reduces heat losses by 90% through external building envelopes when compared to traditional insulation materials. © 2019 Nova Science Publishers, Inc.