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Radiative heat pumping from the Earth using surface phonon resonant nanoparticles
1Department of Physics and Advanced Materials, University of Technology, Sydney, P.O. Box 123, Broadway, NSW, 2007 Australia. angus.gentle@uts.edu.au
Nano Letters
|January 9, 2010
Summary
Radiative cooling using silicon carbide (SiC) and silicon dioxide (SiO2) nanoparticles can achieve subambient temperatures. Combining these nanoparticles in practical cooling systems offers a low-cost, high-performance solution for passive cooling applications.
Area of Science:
- Materials Science
- Nanotechnology
- Thermodynamics
Background:
- Nanoparticles with specific infrared absorption bands can enable radiative cooling below ambient temperatures.
- Atmospheric transparency windows allow thermal emission to space, facilitating passive cooling.
- Silicon carbide (SiC) and silicon dioxide (SiO2) nanoparticles exhibit unique spectral properties for infrared applications.
Purpose of the Study:
- To investigate the potential of nanoparticles for subambient radiative cooling.
- To analyze the performance of SiC and SiO2 nanoparticles in cooling applications.
- To evaluate a practical cooling rig utilizing a mixture of these nanoparticles.
Main Methods:
- Optical properties of SiC and SiO2 nanoparticles were analyzed.
- Subambient cooling performance was assessed for doped polyethylene on aluminum substrates.
- A cooling rig incorporating a mixture of SiC and SiO2 nanoparticles was designed and tested.
Main Results:
- SiC nanoparticles show resonance from 10.5 to 13 mum, outside the ozone band.
- SiO2 nanoparticles absorb from 8 to 10 mum, covering the ozone emission band.
- A mixture of SiC and SiO2 nanoparticles demonstrated high-performance, low-cost cooling.
Conclusions:
- Nanoparticle-based radiative cooling is a viable method for achieving subambient temperatures.
- The spectral complementarity of SiC and SiO2 nanoparticles enhances cooling efficiency.
- Practical cooling rigs using nanoparticle mixtures offer a cost-effective solution for passive cooling.
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