Two-stage vortex tube assemblies including an internal vortex generation chamber for generating a main vortex and a compressed air inlet having a tangential outlet port for creating a pre-vortex in an inflow of compressed air in a direction of flow of the main vortex. The two-stage vortex assemblies may be utilized in low pressure and low flow applications such as seat climatization, local heating or cooling, etc. Further disclosed are seat constructions and seat climatization systems utilizing a two-stage vortex tube as a single source for heating or cooling.