Really good thermal management is critical to the longevity of an LED
The diodes in a LED fitting do not have enough material or surface area to be able to dissipate heat away from the centre (or ‘junction point’). They must therefore be bonded to other thermally conductive material to remove heat from the diodes. The higher the light output, the more heat is generated and the more thermal management is required.
Being physically larger you can get better thermal management in a dedicated LED fitting rather than a retrofit LED lamp, which is one reason why you get more light and a longer life from a dedicated LED fitting.
Retrofit LED lamps have a shorter life but again we use the best available, typically c.35,000 - 40,000 hours.
Like fluorescent, the light output from an LED will decline over time. The dedicated LED fittings we use and sell have superb longevity and reliability with an expected lifespan of 50,000 hours. If used for an average of 6 hours per day every day, this equates to nearly 23 years.