Even the new generation LED lamps are like that (Cree X and such)? I read something the other day that suggested these LEDs were immune to losing efficiency over time (the efficiency would be dictated only by heat).
Yes, LEDs will last longer without heat issues. But unless you're running the LED in a refrigerator, that's not a particularly informative statement.
As stated in the DOE that I linked to: "The primary cause of LED lumen depreciation is heat generated at the LED junction." Because it's the primary cause, you can't just ignore it and say that LEDs barely degrade in the absence of heat. You have to consider the heat when calculating LED lifetime.
The stated lifetime on the LED packaging makes a number of assumptions, one of which is that the LED is run at room temperature.
As stated in the DOE that I linked to: "The primary cause of LED lumen depreciation is heat generated at the LED junction." Because it's the primary cause, you can't just ignore it and say that LEDs barely degrade in the absence of heat. You have to consider the heat when calculating LED lifetime.
The stated lifetime on the LED packaging makes a number of assumptions, one of which is that the LED is run at room temperature.