On Wednesday 09 March 2005 01:47, Gene Heskett wrote: > >So... running a light bulb in a closed room (no windows) is "free" > > as well, for a house that is heated by electrical resistance > > furnace or base board heater? > > Yup. Almost! (please see below for some more relevant information) A fast, but propably not so relevant, estimate: A typical light bulb has a filament temperature of 2500 K, then approximately 0.05 % of the blackbody radiation falls below the THz range at which almost anything is practically transperant. At higher frequencies the transmissibility greatly depends on the material. (For an overheated computer with a surface temperature of 45C the fraction is 5%, though most heat is transfered be convection.) Assuming that the lamp reaches a temperature of 75C and has perfect thermal contact to the copper wire. The wires run outside the walls at 5C and the wires are 1.5 mm2 and 1 m long. The loss due to heat conduction is then approx. 0.1 W or 0.1 percent for 100 W lamp. These numbers are of course ridiculous small, however claiming that efficiency is 100% is wrong even under such idealized conditions. > >My conclusion from this thread is - people who heat their house by > >electrical resistance are paying too much. I knew this already, but > >this illustrates the point. "You might as well heat your house by > > light bulbs or computers!" Real people does not live in houses without windows. People living in contries that does not rely on military to secure their energy supply and does not have a moron for president does not use resistive heaters. > People like 3 of my sons, who are in the Central City area, have > converted to, or are converting to, electric heat, its only half as > much when it comes time to write the check. The gas situation is so > outragious that when one of them had the gas shut off because he was > finally 100% electric, he kept getting a bill for $50 every month, > not for the gas mind you, but because they left a gas meter on his > property and were charging him for the lease/rental of it. He went > to small claims court with a claim of $50 a month for storing it for > them and won, plus the gas folks were ordered to remove any of their > lines that entered or crossed his property. That is at best very short sighted. USA (and Australia) will eventually be forced to sign the Kyoto protocol. With the cuts that USA will have to do to approach the level of more responsible countries, the price of electricity is going to sky rocket. The gas company is then going to reestablish their infrastructure, and the only one to pay are the consumers. Out of curiosity, what is the prices of electricity, oil, gas, gasoline etc. in the USA now? Regards Torben
