The high cost of air conditioning during the summer makes it crucial to develop strategies to reduce energy use in buildings, especially in hot arid climates. Nanomaterial-based external window insulation is considered an effective method for achieving this goal. This research examines the effectiveness of using aerogel-based glazing systems combined with passive design techniques to improve energy efficiency in buildings in hot arid regions. This study presents various scenarios, including building orientation and aspect ratio, utilizing field measurements and energy simulations with aerogel-filled windows. This study is two-phased. The first phase compares two rooms with aerogel and conventional glazing in Aswan. The new glazing system made the room 0.3–1.9 °C cooler. The second phase simulated the Egyptian Japanese School in Aswan to assess the effects of aerogel glazing systems and altering the enclosed semi-open courtyard’s building orientation and aspect ratio. Results show that using aerogel glazing systems and altering the building orientation and aspect ratio can significantly reduce energy consumption and improve indoor thermal comfort. The results reveal that Scenario 1, which represents using aerogel glazing in the northern façade, could reduce the average air temperature between 0.30 and 1.49 °C below the base case (BC). Scenario 3, which used aerogel glazing on the southern facade, reduced annual energy consumption by 26.3% compared to the BC. Meanwhile, Scenario 5, a semi-open courtyard with an aerogel glazing system and an aspect ratio of 2.40, could save 25.7% more energy than Scenario 1. The economic viability of the scenarios was also analyzed using a simple payback period analysis, with Scenario 3 having the second-shortest payback period of 4.13 years. By insulating the exterior panes of windows, this study proposes that adopting aerogel glazing systems can make windows more cost-effective and ecologically sustainable.

Nanomaterial technology involves the fabrication and manipulation of materials at the nanoscale, which can result in novel properties and applications. Aerogel is a nanomaterial that has remarkable properties such as high thermal resistance and optical clarity. These features make it a suitable material for glazing windows in school buildings located in hot and arid regions, where daylighting and thermal performance are important design criteria. This study aims to evaluate the performance of aerogel-glazed windows in classrooms with different orientations and compare them with conventional windows. The study uses Design-Builder software to simulate the daylighting and thermal performance of the classrooms with aerogel-glazed windows in different orientations. The findings show that aerogel glazing on the northern and southern façades reduces heat gain from windows by 7.46 and 26.88%, respectively. East and west orientations should be avoided due to extreme solar heat gain through exterior windows. Investigated glazing systems meet the LEED V4 spatial daytime autonomy (sDA) standards for regularly occupied floor areas, with an acceptable sDA of ≥ 55% for all building orientations. The northern façade exhibited the most favorable results, preserving nearly 69.52% of spatial daylight autonomy and an average daylight factor of 2.65%. The northern orientation also had the highest useful daylight illuminance of 89.6%. Aerogel glazing is an effective building insulation technology that balances classroom window-specific heat gain with daylight in hot dry locations.