This article is about the light polycarbonate diffuser in an LED profile (even glow along the line). It is not an HVAC slot air diffuser (AEROOOM) — air and light are separate axes; see `slot-diffuser-ventilation` / `slot-vs-led-diffuser`.
With light profiles, brightness is not enough: appearance after years matters. Unprotected polycarbonate can yellow; life depends on material quality, UV protection, temperature and the aluminium profile.
Alumineu combines UV-protected polycarbonate (protection inside the material structure, not only a surface film) with an aluminium profile that sinks heat from the LED tape. The light line keeps even glow and original colour longer.
UV drives photo-oxidation — clarity drops, yellow tint rises, especially near windows. Tape heat accelerates ageing if the channel runs hot.
Profiles use primary alloy EN AW-6063 T5 (`aluminium-en-aw-6063-t5`). Diffuser and profile are one system: good polymer in a hot node still ages; good cooling does not replace UV stabilisation. Even yellowing often means material ageing; local spots often mean overheating. Changing only the diffuser without checking the system is incomplete.
### FAQ
Is this the ventilation diffuser? No — LED light diffuser. Air slot = other article / other SKUs.
Why both UV and aluminium? UV from outside; heat from the tape inside. Both protection paths are required.