Abstract: This paper reviews the research progress of energy-saving and heat-insulation films of vehiclewindshields
to reduce energy consumption caused by air conditioners. Some typical film design methods were
introduced, with several experimental results being compared. The films include heat-insulating coating, indiumtin-
oxide (ITO) coating, mono-silver-base or dule-silver-base low-emissivity (Low-E) coating, transparentinsulation
coating and sol-gel coating. The results show that the heat-insulating film technology is most widely
used in the vehicle market, but to obtain both high visible light transmittance and good thermal insulation is
difficult. Transparent-insulation coating and sol-gel coating are the latest rise of insulation films with low infrared
light reflectance. Dual-silver based low-E films which can bear thermal bending are the best solution to obtain
high visible-light transmittance and high infrared reflectance. In the future research focus is to find an excellent
protection material of Ag-layer to slow down or eliminate the oxidation, agglomeration and diffusion phenomenon
of Ag at high temperatures.

Key words: vehicle windshield, energy saving, heat insulation film, low emissivity (Low-E) coating, Sol-gel
coating