PURPOSE: To improve starting performance of a heating system, by enabling the heating system to function also as a hot-wind heating system through utilization of a portion of radiation pipe.

CONSTITUTION: Radiation pipe 6, in which hot water is passed, is arranged along small chambers a, b and so on, in the manner that it covers the entire space inside these small chambers. In surface panel 3 out of opposite surface panels 3, 4, facing the inner space of room to be heated, openings 7 are formed at opposite end portions of one of said small chambers, so that one of these openings 7 is used as air inlet port and the other is used as air outlet port. Air drawn from one of these openings 7 into a small chamber by fan 8 installed in this small chamber is blown off into the room from the other opening 7, so that the small chamber serves as air passage. The small chamber a thus serving as air passage provides a space between heat-insulating material and surface panel 3, in which radiation pipe 6 is exposed. Further, there are provided fin plates 9 in contact with surface panel 3 and radiation pipe 6. With such an arrangement, it is enabled to attain hot-wind heating and to improve starting performance of the heating system.