Hacker News Reader

Comment by erikb | Hacker News Reader

Was that a joke? Both points are wrong. Electric radiators aren't 100% efficient, can't be. e.g., some of the transformed energy will be light (the metal gets red when it starts to get hot).

And of course if you use a computer then X% will go into the computation. The reason why it might be cost efficient for you is because the server guy thinks he has the same costs for electricity no matter if the server is in the data center or in your home, and therefore pay your bills for the server heater.

View on HN

On your second point, no, a 1000W heater will emit the same amount of heat (neglecting visible light losses, which, as other commenters point out, will be converted into heat later on) as a 1000W computer. This is the first law of thermodynamics, and the fact that the computer is doing computation makes no difference.

Part of the energy can get transformed into light (mostly infrared) or sound, but unless it goes out by the window, all that energy will bounce until it's absorbed by a the walls and furniture. It's very easy to get 100% electricity to heat conversion if you have not windows.

You get also 100% conversion with a normal lamp or a sound system (unless they are very close to a window). You get all the heating, and the light or music for free.

I investigated further into that. The confusion arrised from unclear wording in my memory, I guess. You are right electricity to heat is 100%. The inefficiency of electric heat radiators is in the electricity production being inefficient compared to burning the same resources for heat directly.

And that metal getting red emits light, but that light is then absorbed by the surroudings, as it is absorbed it is converted into heat.

No. Energy in a closed system is constant, so if a computer uses 1000W and stays itself at a constant temperature, it releases 1000W as heat.

What do you think that light turns in to?

Please don't contribute to a discussion when you have no idea what you are talking about.

This seems unnecessarily harsh.

Perhaps, but the one thing I find more annoying than people spreading misinformation is when people incorrectly accuse someone else of being incorrect.

However, I will admit that my comment did not add anything useful to the discussion.

Reply on news.ycombinator.com