The goal of RDZ underfloor heating system in the LowUp project funded by the European Commission is to shift the radiant technology to the “upper level”, creating a solution that can be combined not only with alternative energies, but also with the residual thermal energy coming from waste resources. In RDZ system for the LowUp project uniform temperature distribution is achieved through special aluminium diffusers, in both straight and elbow versions, hosting and enveloping PE-RT pipe Ø 14 mm.