Laboratory and pilot scale characterization of granular aerogel glazing systems

The paper deals with the experimental characterization of double glazing units with granular aerogel in cavity at laboratory and pilot scale. In the laboratory investigation, three granule sizes and three aerogel layer thicknesses (10–35 mm) were considered. Light transmittance is in the 0.41–0.75 range (the highest values for the highest granule size and the minimum thickness). The U-value is 1.5 W/m2 K with 10 mm aerogel, whereas it decreases to 0.5 W/m2 K when considering 35 mm of aerogel, regardless of the granules size. After a systematic characterization, aerogel with large granules, the most common on the market, was chosen for an investigation at pilot scale. A window composed of two 6 mm clear float glasses and 15 mm aerogel in gap was tested in an experimental field with two boxes, in comparison with a conventional window. Aerogel sample allowed a reduction in the peak value of the indoor temperature of about 8–9 °C during sunny days, while similar values were achieved in the two test boxes during the night.