On Monday 07 March 2005 20:33, mark@xxxxxxxxxxxxxx wrote: >On Mon, Mar 07, 2005 at 04:27:57PM -0800, Brian Mury wrote: >> On Mon, 2005-07-03 at 17:39 -0500, mark@xxxxxxxxxxxxxx wrote: >> > An electric heater is not 100% efficient and the components in >> > it are *made* to be efficient for the purposes of heating. (I'm >> > not even sure what 100% efficient means when converting >> > electricity to heat - I would think that it would mean 100% >> > electricity in = 100% heat out - which is not the case at all >> > for any sort of electrical heaters that I am familiar with) >> >> Of course an electric heater is 100% efficient. A lightbulb is not >> 100% efficient - it's job is to produce light, but it has loss in >> the form of heat. An electric heater's job is to produce heat - >> and it has loss in the form of what? Heat? Every bit of energy >> consumed by an electric heater generates heat. All of it. Every >> last bit. >> Please tell me where you think the electrical energy that is not >> converted to thermal energy goes. > >Well, now you can show off and explain why some heaters are more > efficient than other heaters. I'm interested. :-) > >Or does it not matter which heater I buy at Canadian Tire - as long > as I look at the capacity rating, I'll know it will cost me the > exact same in electrical costs? Yes, and it will generate the same number of calories/btu per hour as any other identically rated heater. Within the manufacturing tolerances, which could be in excess of 10%, yes. That 1600 Watt rated heater may draw, on a good stiff line with the full rated 127 volts at the socket with the heater plugged in and turned on, a bit over 1750 Watts, all of which will be used at 100% efficiency. OTOH, on a real crappily wired house, that may well exceed the rated carrying capacity of the house wireing to the plug its plugged into, so it will draw only 1350 Watts or so, with another 75 to 100 watts being dissipated in the house wireing feeding it. That will of course lead to a potential fire risk eventually, so I'd certainly NOT recommend that it be plugged into a 15 amp circuit, turned on and ignored for the next 10 years as the wireing *will* eventually fail. I've seen more than my share of older houses with a run of 14 gauge romex feeding a string of 6 to 8 duplexes, and a 30 amp fuse screwed into the socket. Thats twice the rated current carrying capacity of a piece of 14 gauge romex. In the event thats your situation, I'd make damned sure my last will and testament was up to date, and in a safe, offsite place. Even 12 gauge is only legal for 20 amps. In modern wireing practice, and according to the NEC codebook, the rating of the duplex receptacle you are looking at should be readily discerned as the 15 amp circuit has only the two slots and (hopefully) a round hole for the static ground. A 20 amp fed duplex should have one slot shaped like a T with the crossbar being in the same direction as the plain slot in the 15 amp rated device. The wider of the two slots is the neutral side, the narrower is the hot side. >mark (who might be full of crap in his doubt and disbelief of > Brian's electrical engineering logic claiming that, for a house > that requires heating, running a computer 24/7 is virtually > free...) > It is essentially and for all measurement purposes free if the rest of the house is also electrically heated also. Heat is heat, and the rest of the house isn't going to give a flip what it is that generates the calorie's to make up for the insulation and cold air insolation losses. To maintain 68F on a -10F day is gonna take x turns of the wheel in the meter, no more, no less. Electrical wireing itself may be exterior to the insulation in some places, in which case its losses won't generally go toward heating the living space, but these considerations rarely exceed more than 25 watts per well wired house, and would be there regardless of how the energy input in the form of electricity was actually spent within the house. Heck, even the 350-400 watts the average new refrigerator uses to keep its interior cool, is output into the living space in the form of warm air, so in that sense, even the refrigerator is 100% efficient. Even the kilowatt plus an old box uses, is, at the end of the day, 100% heat into the living space. -- Cheers, Gene "There are four boxes to be used in defense of liberty: soap, ballot, jury, and ammo. Please use in that order." -Ed Howdershelt (Author) 99.34% setiathome rank, not too shabby for a WV hillbilly Yahoo.com attorneys please note, additions to this message by Gene Heskett are: Copyright 2005 by Maurice Eugene Heskett, all rights reserved.
