Plant cultivation in a greenhouse (1) may require the use of semiconductor-based devices (6) for a more effective and a more adapted illumination of the plants. The present invention provides a cooling system and a cooling method enabling the use of semiconductor-based devices (6) such as light-emitting diodes mounted on a heat sink (5) for illuminating plants placed in a greenhouse environment. The cooling system is provided with at least one pipe (2) having an incoming end (3) and an outgoing end (4) through which ambient air coming from outside the greenhouse (1) is guided.
