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| Thread ID: 88983 | 2008-04-16 10:14:00 | How efficient is an electric heater? | george12 (7) | PC World Chat |
| Post ID | Timestamp | Content | User | ||
| 659552 | 2008-04-16 10:14:00 | Bletch and I are having a friendly argument about how efficient a basic electric heater is, in terms of how much of the power used is turned into heat. I say approximately 100%, ie 100% minus the tiny amount used as light and noise (that faint hum). This is because inefficiency in electric appliances pretty much always means power wasted as heat, but in the case of a heater, this 'waste' is the desired outcome. Bletch says that the efficiency is much less than this. People, tell me, who's right? By the way, I am fully aware that the result of this poll doesn't say that either of us are right or wrong - it's just interesting. |
george12 (7) | ||
| 659553 | 2008-04-16 10:19:00 | In other words, George's opinion is that a heater consuming 2000W of power will output 2000W of heat. I disagree, I think it will output less than 2000W of heat. George: You might have just started the next airplane thread... |
Erayd (23) | ||
| 659554 | 2008-04-16 10:25:00 | So Bletch, if the heater gives out less than 2kW of heat when 2kW has gone in, into what form of energy is the difference converted? Remember the basic law of conservation of energy. You would have to hang the heater on a spring balance just to check that electrical energy has not been converted into mass :) We could start a new poll on what is the difference between mass and weight :) |
Terry Porritt (14) | ||
| 659555 | 2008-04-16 10:27:00 | It won't convert exactly 2kw of electricity into 2kw of infrared but close enough. | Winston001 (3612) | ||
| 659556 | 2008-04-16 10:30:00 | heaters are 100% efficient, Noise, infrared and light is ultimately absorbed as heat. Unless energy is returned to some sort of storage (pumping water up hill, spinning a mass, putting a satellite in to orbit) all energy ends up as heat. |
porkster (6331) | ||
| 659557 | 2008-04-16 10:32:00 | Consider the following scenario. If you replaced the heater bar with a 50cm thick copper brick, would you get any heat? Not really. The heater bar gets hot because it offers more resistance to the flow of electrons, but at the end of the day the electrons still move from a to b. Remember that circuits are a cycle. | Erayd (23) | ||
| 659558 | 2008-04-16 10:35:00 | I think if you had 2kw of power across a copper brick it would produce 2kw of heat, just like a 2kw heater. | george12 (7) | ||
| 659559 | 2008-04-16 10:52:00 | Although the heater is almost 100% efficient at converting electricity to heat, you should also consider the generating station that produced the electricity in the first place. Some of them can be very inefficient. |
decibel (11645) | ||
| 659560 | 2008-04-16 11:02:00 | Edit: Scrap that. I just thought of another point to back my argument. I'm not admitting defeat yet! | Erayd (23) | ||
| 659561 | 2008-04-16 11:04:00 | Although the heater is almost 100% efficient at converting electricity to heat, you should also consider the generating station that produced the electricity in the first place . Some of them can be very inefficient . Yes, but that's not part of this argument . We're talking about the electricity the heater uses at the home end . |
george12 (7) | ||
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