5 ms·

Not sure why you say "very, very close". The efficiency for heating of all electrical devices is identical, unless they're somehow transmitting energy to a dif

by tgflynn 11y ago

Not sure why you say "very, very close". The efficiency for heating of all electrical devices is identical, unless they're somehow transmitting energy to a different location.

Kliment 11y ago
The highest-efficiency electric heaters use heat pumps for efficiencies way above unity.
- tgflynn 11y ago
  Heat pumps aren't usually called electric heaters though. Electric heaters are usually considered to be devices that generate heat by consuming electricity, not devices that transfer heat. In any case a heat pump obviously falls into the category of a device that transmits energy to a different location, which my comment excluded.
Symbiote 11y ago
> unless they're somehow transmitting energy to a different location. Computers do this in the form of sound, fans, magnetic fields and network connections. Of course, that's a very small amount of energy.
- robotresearcher 11y ago
  The sound, fans and fields all end up as heat pretty soon too. A tiny bit of energy is stored in the bits of permanent storage. That can be kept for (presumably) indefinite time, and not released as heat until the bits are erased. The network connection energy is mostly lost as heat in the wire, but to the extent that it transmits information elsewhere that energy is also retained. Hence very, very close, but not identical, unless you have the pathological condition of never storing any data or causing any other process to store data. To do this you'd have to compute away and no-one could ever learn the results. Edit: I may be wrong about the net heating due to storage, since setting storage bits implies erasing their old state which releases heat into the room. Anyone with better thermodynamics training than me want to give a better answer? Or maybe I should get back to work...
  - tgflynn 11y ago
    Ah OK, I hadn't thought of potential energy in permanent storage.

by tgflynn 11y ago

Not sure why you say "very, very close". The efficiency for heating of all electrical devices is identical, unless they're somehow transmitting energy to a different location.

Kliment 11y ago

The highest-efficiency electric heaters use heat pumps for efficiencies way above unity.

tgflynn 11y ago
Heat pumps aren't usually called electric heaters though. Electric heaters are usually considered to be devices that generate heat by consuming electricity, not devices that transfer heat. In any case a heat pump obviously falls into the category of a device that transmits energy to a different location, which my comment excluded.

Symbiote 11y ago

> unless they're somehow transmitting energy to a different location. Computers do this in the form of sound, fans, magnetic fields and network connections. Of course, that's a very small amount of energy.

robotresearcher 11y ago
The sound, fans and fields all end up as heat pretty soon too. A tiny bit of energy is stored in the bits of permanent storage. That can be kept for (presumably) indefinite time, and not released as heat until the bits are erased. The network connection energy is mostly lost as heat in the wire, but to the extent that it transmits information elsewhere that energy is also retained. Hence very, very close, but not identical, unless you have the pathological condition of never storing any data or causing any other process to store data. To do this you'd have to compute away and no-one could ever learn the results. Edit: I may be wrong about the net heating due to storage, since setting storage bits implies erasing their old state which releases heat into the room. Anyone with better thermodynamics training than me want to give a better answer? Or maybe I should get back to work...
- tgflynn 11y ago
  Ah OK, I hadn't thought of potential energy in permanent storage.