If a machine is never 100% efficient transforming energy into work because part of the energy is converted into heat, does it mean an electric heater is 100% efficient? @showerthoughts@lemmy.world
If a machine is never 100% efficient transforming energy into work because part of the energy is converted into heat, does it mean an electric heater is 100% efficient? @showerthoughts@lemmy.world
Essentially all electrical devices are, in addition to whatever else they do, also basically 100% efficient space heaters. A PC running on 300 watts is doing things with that 300 watts but it all ends up as heat, the vast majority of which stays in the room. A light bulb puts out light, but little of that light leaves the house, it’s all getting reflected and absorbed until it’s mostly a heater in your house.
Consuming energy to do something the device isn’t intended to do is the definition of inefficiency. You’ve basically redefined efficiency so as to make it meaningless.
They didn’t redefine efficiency. They changed the purpose scoping.
If a light bulb gets dinged for leaking light outside of the house, then a computer, a computational and informational device, should also get dinged for any light not absorbed by eyeballs and any errant processes/calculations running without discrete need
The light leaving the house decreases heating efficiency because the energy quite literally went out the window. If you run needless calculations or look away from the monitor, that energy still ends up heating your house
The visible light from a light bulb escaping the house is a very small amount of energy. If it’s an incandescent, then it likely loses a lot of infrared radiation, the primary product of an incandescent bulb, out the window as well (although this would be mitigated by IR-reflecting glass commonly found in the last 20 years). If it’s a fluorescent or LED though, there’s almost no infrared radiation by comparison and very little energy is thrown out the window. Nearly all the heat they generate is inside the base and carried away mostly by convection, partly by conduction, and a little by radiation.
So yes, we can use items as minor home heaters. I’m literally doing that right now at my new place by leaving the incandescents in place to help a 30 year old hvac system. There are pools and office sout there being heated by bitcoin mining farms. But what about in 3 months when I need to cool the house? Suddenly, the charitable heating of wasteful appliances stops making sense. I stand by what I said: if a light bulb gets dinged for losing energy out the window, a computer gets dinged for <100% efficiency on its primary purpose.