Appropriate technology to improve thermal performance of existing window

Technological development for reduction of CO2 emissions has been actively carried out globally. In buildings, windows and envelops are the parts that generate the greatest heat loss. Therefore, it is the target to improve primarily for the energy efficiency. Various techniques such as vacuum glass and heat-insulating reinforced frame have been developed to improve the thermal performance of windows, however, these techniques can be applied only for new windows. To apply these technologies, it is necessary to install them in a building on construction or to replace all of windows of existing building. In this paper, we developed the technology to improve the thermal performance of existing windows. This technology can be applied without any movement of occupants or furniture. Moreover, it is affordable, durable and available for everyone without any special expertise or tools. Another benefit of this technology is that it does not affect daylighting and view since it has a high transmittance. In order to verify the performance of it in terms of the thermal aspect, the mock-up experiment and the field test were conducted. Thermal transmittance of windows was measured and analyzed before and after improving their thermal performance with the technology. The result shows that the values of the thermal transmittance of windows have improved by 20% after application of the technology.