Energywindows

Energywindows is a category of glazing systems designed to reduce building energy use by controlling heat transfer and solar radiation. These windows typically feature dynamic or multi-layered glazing with selective coatings and advanced frames to reduce heating and cooling loads while maintaining daylight and view.

Key technologies include dynamic glazing such as electrochromic, liquid crystal, thermochromic, and suspended particle devices, which change transmittance in response to voltage, temperature, or light. Other approaches include gas-filled double or triple panes with low-emissivity coatings, vacuum insulated glazing, and spectrally selective tints that transmit visible light while reflecting infrared radiation. Some systems integrate shading devices or sensors with building management systems.

Energywindows operate by balancing solar gains and heat losses. In winter, high transmittance and thermal resistance help capture heat and reduce heating needs; in summer, reduced solar gain and improved insulation lower cooling demands. The performance depends on climate, orientation, and window size, and is often evaluated using metrics such as U-factor, solar heat gain coefficient, and daylight availability.

Applications include new construction and retrofit projects in residential, commercial, and institutional buildings. Benefits cited include lower energy bills, improved thermal comfort, reduced peak electricity demand, and enhanced acoustics and daylighting. Some implementations also integrate with smart-home or building automation platforms.

Challenges include higher initial costs, long payback periods in mild climates, durability concerns for dynamic coatings, and the need for skilled installation. Market adoption varies by region and building code requirements; research continues to improve material longevity and reduce cost. The term is sometimes used interchangeably with advanced glazing or smart glass.