Dual-mode heating and cooling devices and related systems and methods
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. The device may include a film with the cooling part and the heating part side-by-side on the film.
1. A dual-mode heating and cooling system comprising:
a dual-mode heating and cooling device comprising 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, the cooling part configured to provide radiative cooling to a structure, the heating part configured to provide solar heating to the structure,
wherein the device comprises a film with the cooling part and the heating part side-by-side on the film.
2. The system of claim 1 wherein the device comprises a first roller and a second roller with the film coupled to the first roller and the second roller, and wherein the first roller and the second roller are configured to be rotated in a first direction to expose the cooling part to the sunlight and in a second direction to expose the heating part to the sunlight.
3. The system of claim 2 wherein the heating part is at least partially wound around the first roller when the cooling part is exposed to the sunlight, and wherein the cooling part is at least partially wound around the second roller when the heating part is exposed to the sunlight.
4. The system of claim 2 wherein the device comprises a housing surrounding the film and the first roller and the second roller.
5. The system of claim 2 further comprising a first cleaning mechanism adjacent the first roller and a second cleaning mechanism adjacent the second roller, wherein the first cleaning mechanism and the second cleaning mechanism are configured to remove debris from the film.
6. The system of claim 1 wherein the film comprises a substrate, wherein the cooling part comprises a solar-reflecting layer on the substrate and an infrared-emitting layer on the solar-reflecting layer, and wherein the heating part comprises a metallic layer comprising metal and/or metallic nanoparticles on the substrate.
7. The system of claim 6 wherein the substrate comprises polyimide, wherein the solar-reflecting layer of the cooling part comprises silver, wherein the infrared-emitting layer comprises polydimethylsiloxane, and/or wherein the metallic layer of the heating part comprises copper and zinc.
8. The system of claim 6 wherein the infrared-emitting layer of the cooling part has substantial infrared absorption in wavelengths of 7 to 20 microns.
9. The system of claim 1 further comprising a voltage source configured to supply a voltage to the film to reduce the thermal contact resistance between the film and the structure.
10. The system of claim 9 wherein the voltage source is configured to supply a voltage of about 2 kV to the film.
11. The system of claim 1 further comprising a temperature sensor and a controller, wherein the controller is configured to direct the system to expose the cooling part to the sunlight when the temperature is above a predetermined temperature and to expose the heating part to the sunlight when the temperature is below the predetermined temperature.
12. The system of claim 1 wherein the structure comprises a roof, a wall, and/or a heat exchanger.
13. A method for dual-mode heating and cooling of a structure, the method comprising:
providing a dual-mode heating and cooling device comprising 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, the cooling part configured to provide radiative cooling to a structure, the heating part configured to provide solar heating to the structure, wherein the device comprises a film with the cooling part and the heating part side-by-side on the film;
cooling a structure to which the device is coupled in the cooling mode;
heating the structure in the heating mode; and
automatically switching between the cooling and heating steps multiple times in response to a measured outside temperature.
14. The method of claim 13 wherein the device comprises first and second rollers, the method comprising rotating the rollers in a first direction to expose the cooling part and rotating the rollers in a second, opposite direction to expose the heating part.
15. The method of claim 13 further comprising applying voltage to the film to reduce the thermal contact resistance between the film and the structure.
16. The method of claim 15 further comprising removing the voltage from the film while maintaining a static charge between the film and the structure.