Abstract: Various aspects as described herein are directed to a radiative cooling device and method for cooling an object. As consistent with one or more embodiments, a radiative cooling device includes a solar spectrum reflecting structure configured and arranged to suppress light modes, and a thermally-emissive structure configured and arranged to facilitate thermally-generated electromagnetic emissions from the object and in mid-infrared (IR) wavelengths.

Abstract: Various aspects as described herein are directed to a radiative cooling device and method for cooling an object. As consistent with one or more embodiments, a radiative cooling device includes a solar spectrum reflecting structure configured and arranged to suppress light modes, and a thermally-emissive structure configured and arranged to facilitate thermally-generated electromagnetic emissions from the object and in mid-infrared (IR) wavelengths.

Abstract: As climate change and global energy consumption manifest in rising global temperatures and heat-islands, cooling living environments has become an urgent challenge. In developed settings, air-conditioning of buildings consumes energy, generates heat and releases greenhouse gases—exacerbating cooling needs. In developing regions, such as South Asia and sub-Saharan Africa, inadequate power infrastructure for cooling buildings has led to rising casualties during summers. Passive cooling technologies, which are sustainable alternatives to active cooling methods are provided. Systems and methods for passive radiative cooling coatings are provided as an effective approach for passive daytime radiative cooling of buildings.

Abstract: In most buildings energy for space heating and cooling can be used to maintain the thermal comfort of the building's human occupants by maintaining the interior air temperature at a set point. If one could maintain the human occupant's thermal comfort while decreasing the heating or increasing the cooling set point, energy savings are possible. Many embodiments implement methods and systems of tunable emissivity surfaces in improving building efficiency. Several embodiment implement tuning the thermal emissivity of interior building surfaces at long-wave infrared wavelengths to maintain thermal comfort.

Abstract: Systems and methods for passive radiative cooling via structures attached to vertical (e.g. walls of buildings) or horizontal surfaces (e.g. roofs) with limited view of the sky by specifically radiating heat in the long-wavelength infrared window of the atmosphere, and designs for doing so are provided.

Abstract: Various aspects as described herein are directed to a radiative cooling device and method for cooling an object. As consistent with one or more embodiments, a radiative cooling device includes a solar spectrum reflecting structure configured and arranged to suppress light modes, and a thermally-emissive structure configured and arranged to facilitate thermally-generated electromagnetic emissions from the object and in mid-infrared (IR) wavelengths.

Abstract: Various aspects as described herein are directed to a radiative cooling apparatuses and methods for cooling an object. As consistent with one or more embodiments, a radiative cooling apparatus includes an arrangement of a plurality of different material located at different depths along a depth dimension relative to the object. The plurality of different material includes a solar spectrum reflecting portion configured and arranged to suppress light modes, thereby inhibiting coupling of the incoming electromagnetic radiation, of at least some wavelengths in the solar spectrum, to the object at a range of angles of incidence relative to the depth dimension. Further, the plurality of material includes a thermally-emissive arrangement configured and arranged to facilitate, simultaneously with the inhibiting coupling of the incoming electromagnetic radiation, the thermally-generated electromagnetic emissions from the object at the range of angles of incidence and in mid-IR wavelengths.

Abstract: Various aspects as described herein are directed to a radiative cooling apparatuses and methods for cooling an object. As consistent with one or more embodiments, a radiative cooling apparatus includes an arrangement of a plurality of different material located at different depths along a depth dimension relative to the object. The plurality of different material includes a solar spectrum reflecting portion configured and arranged to suppress light modes, thereby inhibiting coupling of the incoming electromagnetic radiation, of at least some wavelengths in the solar spectrum, to the object at a range of angles of incidence relative to the depth dimension. Further, the plurality of material includes a thermally-emissive arrangement configured and arranged to facilitate, simultaneously with the inhibiting coupling of the incoming electromagnetic radiation, the thermally-generated electromagnetic emissions from the object at the range of angles of incidence and in mid-IR wavelengths.

Abstract: Various aspects as described herein are directed to a radiative cooling device and method for cooling an object. As consistent with one or more embodiments, a radiative cooling device includes a solar spectrum reflecting structure configured and arranged to suppress light modes, and a thermally-emissive structure configured and arranged to facilitate thermally-generated electromagnetic emissions from the object and in mid-infrared (IR) wavelengths.

Abstract: Various aspects as described herein are directed to a radiative cooling device and method for cooling an object. As consistent with one or more embodiments, a radiative cooling device includes a solar spectrum reflecting structure configured and arranged to suppress light modes, and a thermally-emissive structure configured and arranged to facilitate thermally-generated electromagnetic emissions from the object and in mid-infrared (IR) wavelengths.

Abstract: Various aspects as described herein are directed to a radiative cooling apparatuses and methods for cooling an object. As consistent with one or more embodiments, a radiative cooling apparatus includes an arrangement of a plurality of different material located at different depths along a depth dimension relative to the object. The plurality of different material includes a solar spectrum reflecting portion configured and arranged to suppress light modes, thereby inhibiting coupling of the incoming electromagnetic radiation, of at least some wavelengths in the solar spectrum, to the object at a range of angles of incidence relative to the depth dimension. Further, the plurality of material includes a thermally-emissive arrangement configured and arranged to facilitate, simultaneously with the inhibiting coupling of the incoming electromagnetic radiation, the thermally-generated electromagnetic emissions from the object at the range of angles of incidence and in mid-IR wavelengths.

Abstract: Various aspects as described herein are directed to a radiative cooling apparatuses and methods for cooling an object. As consistent with one or more embodiments, a radiative cooling apparatus includes an arrangement of a plurality of different material located at different depths along a depth dimension relative to the object. The plurality of different material includes a solar spectrum reflecting portion configured and arranged to suppress light modes, thereby inhibiting coupling of the incoming electromagnetic radiation, of at least some wavelengths in the solar spectrum, to the object at a range of angles of incidence relative to the depth dimension. Further, the plurality of material includes a thermally-emissive arrangement configured and arranged to facilitate, simultaneously with the inhibiting coupling of the incoming electromagnetic radiation, the thermally-generated electromagnetic emissions from the object at the range of angles of incidence and in mid-IR wavelengths.

Abstract: Aspects of the present disclosure are directed to providing and/or controlling electromagnetic radiation. As may be implemented in accordance with one or more embodiments, an apparatus includes a first structure that contains an object, and a second structure that is transparent at solar wavelengths and emissive in the atmospheric electromagnetic radiation transparency window. The second structure operates with the first structure to pass light into the first structure for illuminating the object, and to radiatively cool the object while preserving the object's color.

Abstract: Various aspects as described herein are directed to a radiative cooling device and method for cooling an object. As consistent with one or more embodiments, a radiative cooling device includes a solar spectrum reflecting structure configured and arranged to suppress light modes, and a thermally-emissive structure configured and arranged to facilitate thermally-generated electromagnetic emissions from the object and in mid-infrared (IR) wavelengths.

Abstract: Various aspects as described herein are directed to a radiative cooling device and method for cooling an object. As consistent with one or more embodiments, a radiative cooling device includes a solar spectrum reflecting structure configured and arranged to suppress light modes, and a thermally-emissive structure configured and arranged to facilitate thermally-generated electromagnetic emissions from the object and in mid-infrared (IR) wavelengths.

Abstract: Aspects of the present disclosure are directed to providing and/or controlling electromagnetic radiation. As may be implemented in accordance with one or more embodiments, an apparatus includes a first structure that contains an object, and a second structure that is transparent at solar wavelengths and emissive in the atmospheric electromagnetic radiation transparency window. The second structure operates with the first structure to pass light into the first structure for illuminating the object, and to radiatively cool the object while preserving the object's color.

Abstract: Various aspects as described herein are directed to a radiative cooling apparatuses and methods for cooling an object. As consistent with one or more embodiments, a radiative cooling apparatus includes an arrangement of a plurality of different material located at different depths along a depth dimension relative to the object. The plurality of different material includes a solar spectrum reflecting portion configured and arranged to suppress light modes, thereby inhibiting coupling of the incoming electromagnetic radiation, of at least some wavelengths in the solar spectrum, to the object at a range of angles of incidence relative to the depth dimension. Further, the plurality of material includes a thermally-emissive arrangement configured and arranged to facilitate, simultaneously with the inhibiting coupling of the incoming electromagnetic radiation, the thermally-generated electromagnetic emissions from the object at the range of angles of incidence and in mid-IR wavelengths.

Abstract: Aspects of the present disclosure are directed to providing and/or controlling electromagnetic radiation. As may be implemented in accordance with one or more embodiments, an apparatus includes a first structure that contains an object, and a second structure that is transparent at solar wavelengths and emissive in the atmospheric electromagnetic radiation transparency window. The second structure operates with the first structure to pass light into the first structure for illuminating the object, and to radiatively cool the object while preserving the object's color.

Abstract: Various aspects as described herein are directed to a radiative cooling device and method for cooling an object. As consistent with one or more embodiments, a radiative cooling device includes a solar spectrum reflecting structure configured and arranged to suppress light modes, and a thermally-emissive structure configured and arranged to facilitate thermally-generated electromagnetic emissions from the object and in mid-infrared (IR) wavelengths.