A system for illuminating and for heating and/or cooling and/or ventilating and a room, comprising: a plurality of air-conditioning modules having a flat surface, which is arranged to discharge light and heat and/or cold to the room; at least one distribution module which is arranged to provide the plurality of air-conditioning modules with a fluid carrier medium for heat and/or cold and/or fresh air; and a control device for controlling a quantity of heat and/or cold and/or fresh air; wherein the contours of the plurality of air-conditioning modules and the at least one distribution module are arranged in such a way that the plurality of air-conditioning modules and the at least one distribution module form, by virtue of their assembly, a substantially flat and continuous surface, and the surfaces of the plurality of air-conditioning modules each has a plurality of scattering centers for scattering light, wherein the light is emitted by lighting means, which are arranged in an edge region of the surface or in the middle of the surface, wherein each air-conditioning module comprises hydraulic heating circuits and/or cooling circuits for a fluid carrier medium for providing heat and/or cold, each of the plurality of air-conditioning modules is connected separately to at least one distribution module via a controllable valve, and the control device is configured to separately control each of the controllable valves so that the quantity of heat and/or cold and/or fresh air is separately controllable for each of the plurality of air conditioning modules, wherein the at least one distribution module comprises said plurality of controllable valves, the heating and/or cooling circuits are in thermal contact with the surface of the air-conditioning modules for a heat transfer between the fluid carrier medium and the surface, and the scattering centers are arranged as microprisms, microprism arrays, microlenses and/or microlens arrays arranged on or in the surface, which cause diffuse scattering of the light emitted by the lighting means into the room. a plurality of air-conditioning modules having a flat surface, which is arranged to discharge light and heat and/or cold to the room; at least one distribution module which is arranged to provide the plurality of air-conditioning modules with a fluid carrier medium for heat and/or cold and/or fresh air; and a control device for controlling a quantity of heat and/or cold and/or fresh air; wherein the contours of the plurality of air-conditioning modules and the at least one distribution module are arranged in such a way that the plurality of air-conditioning modules and the at least one distribution module form, by virtue of their assembly, a substantially flat and continuous surface, and the surfaces of the plurality of air-conditioning modules each has a plurality of scattering centers for scattering light, wherein the light is emitted by lighting means, which are arranged in an edge region of the surface or in the middle of the surface, wherein each air-conditioning module comprises hydraulic heating circuits and/or cooling circuits for a fluid carrier medium for providing heat and/or cold, each of the plurality of air-conditioning modules is connected separately to at least one distribution module via a controllable valve, and the control device is configured to separately control each of the controllable valves so that the quantity of heat and/or cold and/or fresh air is separately controllable for each of the plurality of air conditioning modules, wherein the at least one distribution module comprises said plurality of controllable valves, the heating and/or cooling circuits are in thermal contact with the surface of the air-conditioning modules for a heat transfer between the fluid carrier medium and the surface, and the scattering centers are arranged as microprisms, microprism arrays, microlenses and/or microlens arrays arranged on or in the surface, which cause diffuse scattering of the light emitted by the lighting means into the room.