A tubular LED light source, based on a tube manufactured in a heat conducting material (1). The LED's (2) are mounted on a part of the outer surface of the tube. Thereby they conduct their heat to the tube, which transfers the heat to the surroundings by cooling fins (6) located on the other part of the outer surface of the tube. Inside the tube the control electronic (7) is placed. It is electrically connected with the LED's on the outer surface of the tube, and with connectors (10) in each end of the tube. The connectors makes it possible to install the light source in existing fluorescent tube fittings, as a direct replacement for fluorescent tubes. There is vacuum (20) inside the tube, so that no damaging condensed water is generated in cold environments. The control electronics can turn on/off and adjust the light level from LED's, and adjust the color components (RGB) of the light. Hereby different color temperatures can be generated. The light source has sensors for detection of movements in the surroundings, and for measuring the spectrum of the light, in the surroundings. The control electronics can communicate with other light sources or a central control unit, by the existing power cable. Further it can be log informations about the operation of the light source too, for further analysis. Instead of ordinary LED's, organic LED's (OLED) can be used.