A Colorful Electrochromic Infrared Emissivity Regulator for All-Season Intelligent Thermal Management in Buildings

Area of Science:

• Materials Science
• Nanotechnology
• Building Physics

Background:

• Radiative cooling offers building energy-saving potential via high emissivity materials.
• Static radiative cooling materials face challenges like winter overcooling and reduced summer effectiveness due to the urban heat island effect.

Purpose of the Study:

• To design a dynamic infrared emissivity regulator for all-season building thermal management.
• To enable real-time switching between radiative cooling and insulation based on environmental conditions.

Main Methods:

• Development of a multi-film ultrathin electrochromic device.
• Application of nano-photonics theory for multilayer optical films to achieve dynamic emissivity control.
• Integration of high reflectance in non-atmospheric windows to minimize external heat gain.

Main Results:

• The regulator achieves dynamic infrared emissivity modulation within the atmospheric window.
• Demonstrated environmental adaptivity, including response time, cycle life, and bending resistance.
• Achieved ≈2 °C (nighttime) and 3 °C (daytime) temperature adjustments.
• Simulated annual building energy savings of 3.46 MJ m^-2.

Conclusions:

• The developed intelligent regulator offers a viable solution for all-season building thermal management.
• Dynamic emissivity control enhances the effectiveness of radiative cooling and insulation.
• The technology shows promise for improving building energy efficiency and occupant comfort.