Passive radiative cooling below ambient air temperature under direct sunlight

  title={Passive radiative cooling below ambient air temperature under direct sunlight},
  author={Aaswath Pattabhi Raman and Marc Abou Anoma and Linxiao Zhu and Eden Rephaeli and Shanhui Fan},
Cooling is a significant end-use of energy globally and a major driver of peak electricity demand. Air conditioning, for example, accounts for nearly fifteen per cent of the primary energy used by buildings in the United States. A passive cooling strategy that cools without any electricity input could therefore have a significant impact on global energy consumption. To achieve cooling one needs to be able to reach and maintain a temperature below that of the ambient air. At night, passive… Expand
Sub-ambient non-evaporative fluid cooling with the sky
Cooling systems consume 15% of electricity generated globally and account for 10% of global greenhouse gas emissions. With demand for cooling expected to grow tenfold by 2050, improving theExpand
A numerical study of daytime passive radiative coolers for space cooling in buildings
A passive daytime radiative cooler is made of a sky facing surface which can preserve the indoor air temperature below ambient without energy consumption by simultaneously reflecting solar radiationExpand
Radiative Cooling and Thermoregulation in the Earth's Glow
Passive radiative cooling involves a net radiative heat loss into the cold outer space through the atmospheric transmission windows. Due to its passive nature and net cooling effect, it is aExpand
Corrected radiative cooling power measured by equivalent dissipative thermal reservoir method
Abstract A radiative cooler is an optical device which can spontaneously preserve its temperature below ambient by simultaneously reflecting solar radiation and emitting thermal radiation through theExpand
Passive sub-ambient cooling: radiative sky cooling vs. evaporative cooling
Day-and-night radiative sky cooling has emerged as a potential alternative to conventional cooling technologies such as refrigeration-based air conditioning and evaporative wet cooling. BothExpand
Sub-ambient radiative cooling and its application in buildings
  • Lufang Chen, Kai Zhang, Mingquan Ma, Saihong Tang, Fei Li, Xiaofeng Niu
  • Environmental Science
  • 2020
Radiative cooling can effectively reduce energy consumption for building applications. As a passive cooling technology, a radiative cooling system radiates heat into space via infrared radiationExpand
Performance limit of daytime radiative cooling in warm humid environment
Daytime radiative cooling potentially offers efficient passive cooling, but the performance is naturally limited by the environment, such as the ambient temperature and humidity. Here, we investigateExpand
Radiative cooling to deep sub-freezing temperatures through a 24-h day–night cycle
It is theoretically show that ultra-large temperature reduction for as much as 60 °C from ambient is achievable by using a selective thermal emitter and by eliminating parasitic thermal load, and experimentally demonstrate a temperature reduction that far exceeds previous works. Expand
Hybrid concentrated radiative cooling and solar heating in a single system
Summary Radiative cooling is an emerging sustainable technology that does not require electricity to function. However, to realize sub-ambient cooling, the effects of the undesired incident solarExpand
Bulk material based selective infrared emitter for sub-ambient daytime radiative cooling
Through passively emitting excess heat to the outer space, radiative cooling has been demonstrated as an efficient way for energy saving applications. Selective surface with unity emittance onlyExpand


Radiative heat pumping from the Earth using surface phonon resonant nanoparticles.
A mixture of SiC and SiO(2) nanoparticles yields high performance cooling at low cost within a practical cooling rig and optical properties are presented and subambient cooling performance analyzed for doped polyethylene on aluminum. Expand
Radiative cooling to low temperatures: General considerations and application to selectively emitting SiO films
Radiative cooling occurs because the atmospheric emittance is low in the wavelength interval 8–13 μm particularly if the air is dry. We derive expressions which specify the optical propertiesExpand
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For cool roofs the combined effect of the three parameters that define heat gain and loss from a roof, namely solar albedo α, thermal emittance E, and sub-roof R-value, must be considered. AnExpand
Thermal performance of radiative cooling panels
Abstract The performance of panels which cool by.means of thermal infrared heat transfer to the sky is calculated from basic principles. The efficiency of a radiative cooling panel is defined.Expand
Radiative cooling during the day: simulations and experiments on pigmented polyethylene cover foils
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A solar reflecting material for radiative cooling applications : ZnS pigmented polyethylene
Abstract Plastic foils containing nonabsorbing pigments can display a high reflectance of solar radiation combined with a high transmittance in the atmospheric window region in the thermal infrared.Expand
Modeling global residential sector energy demand for heating and air conditioning in the context of climate change
In this article, we assess the potential development of energy use for future residential heating and air conditioning in the context of climate change. In a reference scenario, global energy demandExpand
A nanophotonic solar thermophotovoltaic device.
A full solar thermophotovoltaic device is reported on, which, thanks to the nanophotonic properties of the absorber-emitter surface, reaches experimental efficiencies of 3.2%. Expand
Ultrabroadband photonic structures to achieve high-performance daytime radiative cooling.
This work presents a metal-dielectric photonic structure capable of radiative cooling in daytime outdoor conditions that behaves as a broadband mirror for solar light, while simultaneously emitting strongly in the mid-IR within the atmospheric transparency window, achieving a net cooling power in excess of 100 W/m(2) at ambient temperature. Expand
Coherent emission of light by thermal sources
It is demonstrated that by introducing a periodic microstructure into such a polar material (SiC) a thermal infrared source can be fabricated that is coherent over large distances (many wavelengths) and radiates in well defined directions. Expand