In this note, we are going to learn about Selective Radiator, its characteristics and examples. Welcome to Poly Notes Hub, a leading destination for engineering notes for diploma and degree engineering students.
Author Name: Arun Paul.
What is Selective Radiator?
Unlike a blackbody, it does not emit or absorb radiation uniformly at all wavelengths. Instead, it emits or absorbs light more efficiently at some wavelengths than others. This selective nature makes such radiators valuable in a variety of practical applications, including thermophotovoltaics, solar cells, and thermal insulation.
Key Features of Selective Radiator
Here we have listed some features or characteristics of this radiator –
- Selective Emission and Absorption: These radiators have specific wavelengths where they are more effective at emitting or absorbing radiation. This is usually accomplished by material characteristics or surface structure.
- Applications in Energy Conversion: Selective radiators are used to improve the efficiency of devices such as thermophotovoltaic cells by allowing them to emit radiation primarily in wavelengths that match the photovoltaic material’s bandgap.
- Thermal Insulation: In applications where heat retention is critical, such as thermal insulators, selective radiators can be designed to emit less infrared radiation, resulting in reduced heat loss.
Examples of Selective Radiator
Here we have listed two examples of this radiator –
- Solar Panels: To boost efficiency, use selective coatings that absorb more sunlight (visible spectrum) while reducing infrared emission.
- Low-E Glass: Has coatings that selectively decrease heat transmission by reflecting infrared radiation while allowing visible light through.