Temporal and Spectral Analysis on the Performance of Solar Windows Film in Office Buildings in a Hot-Dry Climate

This study examines the performance of solar window films installed on double-glazed windows of typical offices in actual working conditions in a hot and dry climate. Passive thin films stuck interiorly on double-glazed windows were used to affect various solar-optical impacts including energy saving, UV reduction, and increased thermal comfort. Real-time measurements of environmental parameters, including temperature, humidity, and luminous, were performed continuously in 5-minute intervals over three summer months of June, July, and August 2019 in Kuwait and data were stored automatically through a WiFi system. Arduino-type microprocessors and various temperature, humidity, Lux, and UV sensors were assembled and programmed to transfer and store data in real-time. Temporal and spectral analyses were conducted to compare the effects of the window films on these environmental parameters. It is evident that windows film has good potential to decrease interior temperature and its variability, to save energy and reduce CO2 footprints, to save water by preserving interior humidity to level of human comfort, to restrict the solar UV rays to minimum level, and to reduce visual impacts of high solar luminous in hot-dry climates. The benefits and drawbacks of the selected windows film are discussed.