We tested 3 of each bulb and averaged the test results for each.
To test if the light output of the LEDs was as good as incandescent bulbs and halogen spots, we measured the light output of five incandescent 40W bulbs and averaged the results. We did the same for 5 60W and 75W incandescent bulbs. We then followed a similar procedure for the halogen spotlights.
Once these baselines were established we compared each LED bulb with its incandescent or halogen equivalent.
The model-to-model light outputs varied substantially. The GLS LED bulbs were all “brighter” than their incandescent counterparts and the Panasonic LDAHV8L27H2 had over twice the light output.
The spotlights were different – only 2 of the 12-volt LED bulbs had a higher light output than their equivalent halogen spots. The rest of the LED bulbs, both 230 and 12 volt, were disappointing. The lighting industry has more work to do to make these LEDs a true drop-in replacement for halogen spots.
An incandescent bulb lasts for around 1000 hours, a CFL for around 5000 to 8000 hours, but most LEDs are claimed to last at least 15,000 hours. We simply can’t test for that long. User experience will tell if those claimed lifespans are correct.
LEDs run much cooler than incandescent bulbs. But that’s not the end of the story. LEDs have electronic components in the base of the bulb – and if these components (or the LED chip itself) get too hot (over 60°C), the light output decreases and the bulb may fail early on.
LEDs should only be installed into ventilated fittings where air can move through the fitting. Where LEDs don’t last the distance, the most likely culprit is heat – they don’t like getting too warm.
To get some idea of whether the LED bulbs would last, we put three examples of each bulb in a special test rig that (under computer control) switched them on and then off 12,000 times. There were no failures.
When we last tested CFL bulbs in 2013 using the same rig but only 6000 on-off switching cycles, 18 of our 60 CFLs failed during this test.
An LED bulb can pay for itself with the savings it makes in electricity consumption.
Let’s compare a mid-range LED to a standard incandescent bulb. The LED has the same brightness as a 60 watt incandescent while only drawing 9.5 watts. The LED costs $18 and has an expected lifespan of 15,000 hours, while the equivalent 60 watt incandescent bulb costs 50 cents but lasts for 1000 hours. If the light is on for three hours each day the incandescent will use $17.08 worth of electricity in a year, compared to $2.70 for the LED. That’s a saving of $14.38 per year.
The LED will have paid for itself in a little over a year. It will then keep going for another 12 years if used for three hours every day, while the incandescent bulb will need to be replaced every year. These figures show you shouldn’t wait for your incandescent bulbs to blow – it’s more cost effective to replace them with LEDs now.
Likewise a ceiling full of 35W halogen spotlights (12 bulbs) running for 4 hours per day would cost $153 a year to run. 12 6W LED equivalents would cost just over $26 to run.