The invention relates to process gas conditioning for tobacco dryers. In particular, it relates to a device for conditioning dryer which includes a vaporization unit with a chamber for introducing and vaporizing water to be added to the process gas, wherein the vaporization unit is arranged before the tobacco dryer and before the tobacco is introduced into the process gas. Furthermore, the invention relates to a vaporization unit for introducing water vapor into the flow of process gas in a tobacco dryer which includes a through-flow tank in which water introduced via a number of spray jets is completely vaporized, in contact with the process gas, and to a method for conditioning process gas for a tobacco dryer, in particular a flow dryer, wherein vapor is added to the process gas by introducing and vaporizing water, the water in the flow of process gas being vaporized in an vaporization unit before the tobacco dryer and before the tobacco is introduced into the process gas.