3 ms·

LEDs can light a medium-sized room with <5W. That's incredibly energy efficient.

• moffkalast 4y ago
  Not when you consider that it's still heating the room with 3 of those watts. If you asked me to build a house and I threw away more than half of the bricks you'd call me crazy. But when it comes to leds it's called "incredible efficiency". It's only efficient in comparison to the other options, not in any objective sense.
  • shukantpal 4y ago
    “Efficient” is a relative comparison. Any absolute threshold would be arbitrary anyway
    • moffkalast 4y ago
      Not really. Converting all the energy to work would be 100% efficiency, converting none of it would be 0%. It's an absolute measure. Now sure there are subcategories where 100% efficiency is the maximum theoretical efficiency (like the carnot cycle limit of 37% for heat engines), but that's already misleading info if not specified.
      • shukantpal 4y ago
        You provide no points to refute my statement. Being bounded between 0% and 100% is irrelevant, unless you think only 100% efficient is not inefficient - which would be absurd due to the impossibility of obtaining an “efficient” label.