| abstract |
Thermal device comprising a thermal part ( 20 ) comprising a multitude of heat-transfer tubes ( 21 ) for the passage of a heat-transfer fluid, characterized in that it comprises a light guide ( 10 ) placed above the thermal part ( 20 ), this light guide ( 10 ) having an optical property allowing an incident light ray to be guided in various exit directions depending or the angle of incidence of the incident light ray, so as to orient most of the incident light onto the heat-transfer tubes ( 21 ) at low incidence, such as in winter, and to beside these heat-transfer tubes ( 21 ) at high incidence, such as in summer. |