LED Driver Life vs Temperature Calculator

Exponentially: each 10 K above the 75 °C reference halves expected life, and each 10 K below roughly doubles it (the electrolytic-capacitor Arrhenius rule applied at the driver's tc reference point, as used in driver datasheet life curves). A sustained 20 K overshoot quarters the life — which is why a 'small' cooling problem is never small over the years.

Because temperature is zonal: the row under the roof apex or above the ovens runs hottest, ages fastest, and fails together — same hardware, different microclimate. Measure tc on a sample fixture per zone in summer (IR gun on the marked tc point), run each zone through this calculator, and you can predict replacement waves per zone and budget accordingly — or fit ventilated/remote-driver fixtures in the hot zones and break the cluster pattern.

It is the engineering linearisation of the Arrhenius equation over the normal operating window, adopted by the relevant standards because it matches test data well within ±20–30 °C of the reference. Far outside that window (or where a different failure mechanism takes over, e.g. mechanical wear) the rule loses authority — treat extreme extrapolations as indicative only.

The hot-spot (the hottest point of the insulation/material), because chemistry happens at the hottest spot. If you can only measure surface or ambient, add the typical rise for your equipment class — datasheets usually state hot-spot rise over ambient at rated load — and remember intermittent peaks age the asset during the peak hours, not the average.