A dual-mode heating and cooling system includes a dual-mode heating and cooling device including a cooling part and a heating part that are configured to be selectively exposed to sunlight in a cooling mode and a heating mode, respectively, with the cooling part configured to provide radiative cooling to a structure, and with the heating part configured to provide solar heating to the structure.

Embodiments described herein generally relate a multi-mode heat transfer system. The heat transfer system includes an emitter device. The emitter device includes an inner core, a composite material pattern, and a surface coating pattern. The inner core is surrounded by an outer core having a thickness and an outer surface. The composite material pattern extends through at least a portion of the outer surface and at least a portion of the thickness of the outer core and is thermally coupled to the inner core. The surface coating pattern is on the outer surface and is changeable between a low emissivity state and a high emissivity state based on a surface temperature of the emitter device. In the low emissivity state, the emitter device transmits an omni-directional radiation and, in the high emissivity state, the emitter device transmits a focused radiation via the composite material pattern.

Embodiments described herein generally relate a multi-mode heat transfer system. The heat transfer system includes an emitter device. The emitter device includes an inner core, a composite material pattern, and a surface coating pattern. The inner core is surrounded by an outer core having a thickness and an outer surface. The composite material pattern extends through at least a portion of the outer surface and at least a portion of the thickness of the outer core and is thermally coupled to the inner core. The surface coating pattern is on the outer surface and is changeable between a low emissivity state and a high emissivity state based on a surface temperature of the emitter device. In the low emissivity state, the emitter device transmits an omni-directional radiation and, in the high emissivity state, the emitter device transmits a focused radiation via the composite material pattern.

The present disclosure provides a sunroof system for a vehicle including glass slidably insertable into a vehicle body of the vehicle, and a passive radiant cooling layer disposed below the glass and slidably insertable into the vehicle body. The passive radiant cooling layer includes at least two layers among a first emission layer having a high emissivity in a first band relative to a band outside the first band, a second emission layer having a high emissivity in a second band, which is included in the first band and narrower than the first band, relative to a band outside the second band, and a reflection layer having a high reflectivity in a third band, which is a shorter wavelength than the first band, relative to a band outside the third band.

A microchannel heat exchanger structure with a nozzle and a working method thereof. The microchannel heat exchanger structure with a nozzle, includes a first heat exchange portion, a second heat exchange portion, and at least one nozzle portion between the first heat exchange portion and the second heat exchange portion, the first heat exchange portion having a high-pressure heat exchange channel, a first micro-fin array being provided inside the high-pressure heat exchange channel, and the second heat exchange portion having a low-pressure heat exchange channel, the high-pressure heat exchange channel and the low-pressure heat exchange channel being in communication through at least one nozzle disposed in the nozzle portion. The heat exchanger structure has a good heat exchange effect and can achieve a better heat flux during heat exchange.

A system and method are provided to create porous surface coatings. In use, a material layer includes synthesized carbon-containing composite materials, wherein the synthesized carbon-containing composite materials comprise a porosity characteristic, and at least one of: heat transfer characteristics, resistance to corrosion characteristics, or non-ablative erosion characteristics. Additionally, a bonding layer comprising at least some of the synthesized carbon-containing composite materials is bonded by at least one of, a carbon-to-carbon bond, or a metal-to-carbon bond to a substrate. Further, a surface interfacial layer comprising at least some of the synthesized carbon-containing composite materials is hydraulically smooth.

A radiative cooling device, and a method of manufacturing the same, includes a reflective layer disposed on a substrate and responsible for reflecting sunlight having wavelengths corresponding to ultraviolet, visible, and near-infrared regions; and a radiative cooling layer disposed on the reflective layer and responsible for absorbing sunlight having a wavelength corresponding to a mid-infrared region and emitting the sunlight as heat, wherein the radiative cooling layer includes a first radiation layer including an uneven pattern; and a second radiation layer disposed on the first radiation layer and having a refractive index different from that of the first radiation layer.

A heat dissipation member includes a thermal radiation ceramic material, and the thermal radiation ceramic material contains silicon nitride and boron nitride as main components. The ratio of the mass of boron nitride to the mass of silicon nitride and boron nitride is 10 mass % to 40 mass %.

A heat dissipation member includes a thermal radiation ceramic material, and the thermal radiation ceramic material contains silicon nitride and boron nitride as main components. The ratio of the mass of boron nitride to the mass of silicon nitride and boron nitride is 10 mass % to 40 mass %.

The present invention relates to a method of enhancing heat transfer of metallic surfaces by (1) fabricating hierarchical micro-nanostructured surfaces using etching processes, and (2) fabricating hydrophobic and hydrophilic regions, using a printing or a coating technique, followed by etching. The said method enhances the density of condensation sites over a metallic surface and additionally facilitates the departure of condensed droplets from the surface. Such a surface also enhances the sensible heat transfer characteristics, and improves the coefficient of performance (COP) of refrigeration systems for applications like atmospheric water generators, dehumidifiers, air conditioners, etc.