The product consists solely of hydrophobic silicate aerogel, in form of granules with grain sizes up to 4mm. Different grain size distributions and qualities regarding optical properties are available. The use of unprocessed granules is limited. In the building sector, it is primarily used for the insulation of cavity walls. In this case, the air-filled cavity between the load-bearing wall and the façade wall will be blown out with granules by application of pressure. The use in other cavities is also possible but, to our knowledge, has not been made so far. For both applications, the leakage of dust from small openings in the cavities is a problem. However the granules can be processed to boards or used as an aggregate in an insulating plaster. Granulate of Cabot and Enersens is part of this group.
Granulate of the company Cabot with the product names P100 (Grain size: 0.01 – 4.0 mm), P200 (0.01 – 1.2 mm) and P300 (1.2 – 4.0 mm). The thermal conductivity of the bulk is about 19 mW/(m·K), under (high) compaction lower thermal conductivities of 13 – 14 mW/(m·K) can be reached. In addition, an aerogel of Cabot with a higher light transmission named Lumira is available.
Granulate of the company Enersens is available in various versions: Kwark, Kwark White und Kwark Plus. The thermal conductivity is declared with 18 – 20 mW/(m·K), the change of which under compression has not been evaluated yet.
Blankets consist of a carrier non-woven, in which aerogel is embedded. During production, the liquid raw materials of the aerogel are poured into the carrier non-woven so that the aerogel is created in the non-woven. The non-woven stabilizes the aerogel mechanically, resulting in a flexible, mechanically resilient material. It is available in thicknesses of 5 and 10 mm. The blankets have a very low thermal conductivity. They can be cut, fixed with dowles, glued and bent. Therefore aerogel blankets are a very flexibly applicable material. It is suitable for a variety of construction details, e.g. for the insulation of roller shutter housing or for window reveals, but also for the insulation of ventilation pipes bringing in outside air or for hot water pipes of solar thermal systems. Due to their mechanical flexibility blankets are also suitable for the insulation of façades with external thermal insulation composite system. There is no corresponding system product, but the application at the milling building in Oberhallau has shown, that blankets can be applied successfully in this way. Aerogel blankets are available as the product Spaceloft of the company Aspen Aerogels.
Aerogel insulation blanket with high mechanical flexibility and low thermal conductivity (14 – 15mW/(m·K)). Besides the main application as an industrial insulation especially of oil- and gas pipes, it is used in construction in various areas, e.g. as external thermal insulation composite system or for details of the thermal envelope such as dormers or roller shutter housings. Due to the open pore structure of aerogels also this insulating blanket is diffusion opened, i.e. vapour can pass through the material.
Aerogel boards differ from aerogel blankets in their higher stiffness and in their larger material thickness. Boards are being produced by either bonding for multiple aerogel blankets or by compounding aerogel granulate. With the addition of glue, the thermal conductivity increases in comparison to aerogel blankets. The boards can be used as external thermal insulation composite system or for interior insulation. Depending to the system they have to be glued and doweled or only glued. In Switzerland, the commercially available aerogel products are the Heck AERO board and the Sto Aevero insulation board.
Aerogel insulation board, i.e. a product with higher stiffness and in some cases higher material thickness, which is manufactured by the bonding of individual blankets. The bonding results in a slightly higher thermal conductivity of 17 mW/(m·K). On the other hand another carrier non-woven is used than for Spaceloft in order to reach a non-combustible fire rating. The board is mainly used as an external thermal insulation composite system. Like the Spaceloft blankets it is diffusion open.
Aerogel insulation board which is produced by compounding of Cabot aerogel granulate. The board reaches good thermal properties with 16 mW/(m·K). The fire rating worse than the one of other boards or blankets due to the gluing. The applications of the board are internal insulation as well as the solution of details on the building exterior (window reveals, roller shutter housings, soffitts). An application advantage of the board is that it does not have to be dowelled but is attached only through glueing and that its handling releases very little dust.
Aerogel insulating renders are manufactured by the compounding of aerogel granulate with inorganic binder systems based on lime and/or cement. Like that a thermal con-ductivity is achieved, which is slightly below those of conventional insulation blankets or boards, but which is approximately half of the size of other insulating renders. Aerogel renders are very well suited for use in the renovation of historical façades because on one hand they can replace the present render and on the hand side enable a variable application thickness, which adapts to the circumstances of the façade. In addition, the insulation around the window reveals or the beams of timber-framed houses can be made thinner, so that the appearance of the façade remains with its historical details is conserved. Currently there are two insulation renders available in Switzerland: The product Fixit 222 of Fixit as well as the product HAGATHERM Typ Aerogel of HAGA AG.
This aerogel render, which was developed in with a joint project between Empa und Fixit, binds aerogel granulate from Cabot in an inorganic render mixture, so that the majority of the volume is taken up by the granulate. This results in a good thermal conductivity of 28 mW/(m·K), which is about one-third to one-half the thermal conductivity of conventional insulation renders. The inorganic involvement of granules results in a non-combustible fire rating. In addition the render is diffusion open.
HAGATHERM Typ Aerogel
Also, the company HAGA AG developed an aerogel insulation plaster with a thermal conductivity of 29 mW/(m·K), which is also diffusion open.
Translucent aerogel elements
Translucent elements are composed of a hollow chamber with transparent walls, which are either made of glass or plastic. The chamber is filled with aerogel granulate. Aerogel is transparent in its monolithic form. A granulate filling on the other hand is only translucent be-cause the light is refracted between aerogel and air. Like that, light can pass through the element, but no picture of the objects behind will arise. This diffuse light enables a good illumination of rooms without a harsh shadowing or glare. Therefore translucent aerogel elements are well suited for the application in offices and industrial buildings or in sport or factory halls, both as skylights and as façade elements. At the same time they provide a very good thermal insulation in comparison to normal double or triple glazing. The product Okagel of the company Okalux is available as a translucent element in Switzerland.
Translucent glass-elements, in which aerogel granulate is embedded between two glass panes. Due to the granulate u-values of 0.3 and 0.6 W/(m²·K) are reached – depending on the thickness of the element – while still 45 and 59% of the incident light still passing through the element, respectively.