A Multimodal Smart Window with Visible-NIR-LWIR Electro-Modulation for All Weather.

Area of Science:

• Materials Science
• Sustainable Building Design
• Energy Efficiency

Background:

• Smart windows are crucial for sustainable buildings, but independent control of visible light, near-infrared (NIR) heating, and long-wave infrared (LWIR) cooling remains a challenge.
• Dynamic regulation of multi-functional radiation is needed for varying operational requirements and weather conditions.

Purpose of the Study:

• To develop a multimodal smart window (LHE-ED) capable of independently modulating visible, NIR, and LWIR spectral bands.
• To achieve precise control over lighting, heating, and radiative cooling for enhanced indoor comfort and energy savings.

Main Methods:

• A novel PET/ITO/PB/Pt-NPs electrode was fabricated for dual-band modulation of visible and NIR radiation through ion insertion and electrodeposition.
• Electrochromism and dynamic emittance were manipulated for tri-band modulation, creating six independent electro-driven states.
• Building energy simulations were conducted to evaluate the LHE-ED's performance against commercial low-E glass.

Main Results:

• The LHE-ED demonstrated excellent wavelength selectivity with △T_Vis = 41.24%, △T_NIR = 53.95%, and Δε_8-13µm = 0.35.
• Simulations showed the LHE-ED outperforms commercial low-E glass in various climate zones.
• Significant reductions in CO2 emissions (up to 34.01 kg/m² year) and HVAC energy consumption (34.18% annually) were observed.

Conclusions:

• The developed LHE-ED offers unprecedented tri-band spectral modulation for smart windows.
• This technology significantly improves energy efficiency and reduces environmental impact in buildings.
• The LHE-ED represents a next-generation solution for energy-saving and environmentally friendly building design.