5 ms·

Does the wattage coming in entirely converts to heat? I always assumed it didn't, but have no idea in what proportion.

• mikeash 10y ago
  Energy in has to equal energy out over the long term. For electronics equipment that isn't doing mechanical work then there aren't a lot of options for how that energy can come out: it'll either be electromagnetic radiation of some kind (i.e. light or radio or similar) or heat. Most computer equipment emits relatively little electromagnetic radiation, so it's essentially all heat.
  • 0xffff2 10y ago
    Isn't heat just lower frequency EM radiation?
    • mikeash 10y ago
      Heat can be transmitted through EM radiation (of all frequencies, but IR is predominant for temperatures we're accustomed to) but also by direct contact between materials. For typical temperatures, radiation doesn't transmit much heat. Vacuum makes for a pretty good insulator. If you want to remove 20kW of heat from a small space, you'll need to do most of that removal by transferring the heat to a fluid of some kind, e.g. by putting it into the air. To see the difference in practical terms, pick an item that's noticeably warm, but not hot enough to burn you. Hold your finger very close to it. The heat you feel there is radiated. Then touch it, and feel the heat that's conducted through touch. You'll feel much more heat with the latter.
• throwawayish 10y ago
  The external signalling power used by computers is completely neglible compared to the heat output. Computers and IT equipment in general are essentially ideal heat converters.