The invention relates to a cage system (15) for housing experimental animals which are to experience an environment different from that of a surrounding space (19). The cage system (15) comprises a climate control unit having a vaporizer (1) for generation of water into vapour. The vaporizer (1) comprises a vaporization chamber (4), and water is fed to the vaporization chamber (4) via a liquid supply tube (3). A surface tension breaking device (8) having an open structure is provided at the end (9) of the liquid supply tube (3) so that the water passes therethrough when flowing from the liquid supply tube (3) and into the vaporization chamber (4). Hereby water can be supplied to the vaporization chamber (4) without any significant formation of droplets in the vaporization chamber (4). The vaporizer (1) is used to supply a controllable and uniform flow of vapour to the cages (16) so that a desired humidity can be maintained.
