A polymerization and tempering device (10) comprising at least one lightsource (60) whichemits light in the visible and/or ultraviolet wavelength range, and comprisinga fan (30), a lightchamber (24) and with a door to the light chamber is provided, wherein thepolymerization andtempering device is light-proof and the fan is arranged in an air channel (14)which extendsthrough a housing (12) of the polymerization and tempering device (10) and inparticular blowsair behind at least the light source wall (56).
