The present invention relates to a vaporizer (1) for generation of a flow of vapour to be fed into a stream of gas. The vaporizer (1) comprises a vaporization chamber (4), and liquid 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) which is abutting or protruding into the vaporization chamber (4) so that the liquid passes through the surface tension breaking device (8) when flowing from the liquid supply tube (3) and into the vaporization chamber (4). Hereby liquid can be supplied to the vaporization chamber (4) without any significant formation of droplets in the vaporization chamber (4). The invention further relates to a climate control unit (18) comprising such a vaporizer (1). It further 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 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.
