A climatisation system for wind turbines which comprise: a first heat exchanger (10) in the nacelle (1) for exchanging heat with an element of the nacelle for which the temperature needs to be controlled; a second heat exchanger (20) outside the nacelle (1) for exchanging heat with a first exchange unit (21); a first section (12) of a climatisation circuit for: connecting the first heat exchanger (10) with the second heat exchanger (20); circulating a liquid coolant between the first heat exchanger (10) and the second heat exchanger (20); impulsion units (100) for circulating the liquid coolant on the first section (12) of the climatisation circuit; a shut off valve (200); and expansion tank (400); an expansion valve (300) between the first heat exchanger (10) and the second heat exchanger (20).