5 ms·

Grrr! Incandescent lights, when heating would be used, are 100% efficient. They provide 3% light output, and 97% heat output. A single one on provides a great

by kefka 10y ago

Grrr! Incandescent lights, when heating would be used, are 100% efficient. They provide 3% light output, and 97% heat output. A single one on provides a great amount of heat and can easily provide spot-heat where humans are. Instead there's CFLs and LEDs. And CFLs are a great way to spread mercury pollution across a great area. Snopes has a decent article about hazards and response: http://www.snopes.com/medical/toxins/cfl.asp http://www.snopes.com/medical/toxins/cfl.asp

soperj 10y ago
Not really that useful in places that are already hot, or heating while you want to sleep.
- kefka 10y ago
  Of course, the bulbs would add 97% waste heat if heat isn't wanted. But most places here in the US have some soft of heating system for the winter. That would pretty much require changing out the bulbs for the winter. During sleeping? Scraping the bottom of the bucket much? I never said that incandescents would eliminate heating, only that it is 100% efficient when used appropriately.
  - nkozyra 10y ago
    I think it's a fair point; these bulbs are not used for heating because that's not their primary function (despite being more efficient at it than lighting). The inverse would apply to, say, a fireplace. Light is an acceptable (even desired) side effect of the primary function, but it would not be convenient to rely on it for that side effect.
venomsnake 10y ago
Need a warmish proofing/fermentation chamber - just turn the lightbulbs (2x25W) in your oven on.
kazinator 10y ago
Doesn't work out when heating wouldn't be used, or AC would be. Heating isn't always electric. Using electricity for heating is an egregious waste of a high quality energy source which can do all sorts of useful things besides generating heat.
willvarfar 10y ago
Direct electric is a really inefficient way of heating anything. I ripped out a direct electric heater system and replaced it with a ground source heat pump which is giving 4KW heat for every 1KW electricity (used to run the pump and compressor etc) even in the cold depths of the Swedish winter.
Strilanc 10y ago
You could use the 97% of electricity that was lost to heat to power a heat pump. Heat pumps beat 100% efficiency. [1] > In heating mode, heat pumps are three to four times more efficient in their use of electric power than simple electrical resistance heaters. Instead of just generating waste heat, you generate waste heat and move heat around in a desired way. 1: https://en.wikipedia.org/wiki/Heat_pump https://en.wikipedia.org/wiki/Heat_pump
lutorm 10y ago
Depends strongly on the situation. It's true that where heating would be used, if mounted in such a way that all that heat is available (ie, not recessed into a ceiling fixture), the 97% is useful. (But not necessarily maximally efficient, because if you wanted heat in the first place you'd be better off not turning your energy into electricity, a process with ~50% efficiency at the power plant, and then incurring further distribution losses.) On the other hand, if cooling would be used, it's even less efficient because now you have to cool away all those 97%.
mikeash 10y ago
The electricity for my lights comes from thermal power plants with maybe 40% efficiency and then loses a little bit more in transmission. If I use LED bulbs, then that heat is replaced by my natural gas furnace, which is somewhere around 90% efficient. Net result, even in the dead of winter it saves energy to use more efficient bulbs. In summer, when I'm using electricity to cool my house, the difference is even greater. Resistive heating with electricity is just terribly inefficient. If you have to do it anyway (because you need to run equipment, and that equipment is already as efficient as it'll reasonably get) then you can benefit a little by ensuring that this heat is put somewhere it's wanted. But if you don't have to do it, don't do it. CFLs suck, but LEDs are great. I fear that the CFL interregnum may have hurt the cause of efficient lighting in general.
- ars 10y ago
  > CFLs suck, but LEDs are great. I have both. There's basically no difference, except the LEDs are hot on the base and CFL's are hot on the bulb. Power consumption is identical, CRI identical, and Cost per Hour (before failing) is basically identical (assuming the hours listed on the package is the truth). > I fear that the CFL interregnum may have hurt the cause of efficient lighting in general. It has not. I've been using CFLs for about 20 years (almost since the day they came out), and they work just fine.
  - mikeash 10y ago
    CFLs take longer to come on, don't reach full brightness immediately, are less efficient, don't last as long, and contain mercury. I don't know what your personal statement about using CFLs for 20 years has to do with my fear about the cause of efficient lighting being hurt. Your own preferences don't necessarily reflect those of people in general.
    - ars 10y ago
      > CFLs take longer to come on I have both. That isn't true. I have some LEDs that take longer, some CFL's that take longer, and some (of both) that are effectively instant. > don't reach full brightness immediately Also not true. It used to be that way, and perhaps some poorly designed ones. But there is no reason to buy any that are not instant. > are less efficient Again, not true - make sure to compare bulbs with equivalent CRI. > don't last as long, and contain mercury. This is true, and irrelevant. Also, LEDs cost more, and I'm not (yet) convinced the hour ratings are actually accurate. > I don't know what your personal statement about using CFLs for 20 years has to do with my fear about the cause of efficient lighting being hurt. Your fear is unwarranted. CFLs work perfectly fine, and I know that because I've been using them for a long time.
strommen 10y ago
Sure, but when air-conditioning would be used that equation flips around. Not only do you lose electricity as heat, you need to use more electricity to counteract that heat. And in most places, far more money is spent on cooling than heating. Even in the frozen wastelands of Minnesota where I live, air-conditioning costs over the summer are about equal to heating costs over the winter. As others have mentioned, heat pumps and gas furnaces are much more economical than resistive heating via incandescent lights.
- flubert 10y ago
  >And in most places, far more money is spent on cooling than heating. Hmm. I've always heard the opposite. Anyway, here's one piece of research. http://iopscience.iop.org/article/10.1088/1748-9326/8/1/014050;jsessionid=7C44E1B7D1A0820B5172272C0C0C55F6.c2.iopscience.cld.iop.org http://iopscience.iop.org/article/10.1088/1748-9326/8/1/0140... "Abstract Energy demand for climate control was analyzed for Miami (the warmest large metropolitan area in the US) and Minneapolis (the coldest large metropolitan area). The following relevant parameters were included in the analysis: (1) climatological deviations from the desired indoor temperature as expressed in heating and cooling degree days, (2) efficiencies of heating and cooling appliances, and (3) efficiencies of power-generating plants. The results indicate that climate control in Minneapolis is about 3.5 times as energy demanding as in Miami. This finding suggests that, in the US, living in cold climates is more energy demanding than living in hot climates."

by kefka 10y ago

soperj 10y ago

Not really that useful in places that are already hot, or heating while you want to sleep.

kefka 10y ago
Of course, the bulbs would add 97% waste heat if heat isn't wanted. But most places here in the US have some soft of heating system for the winter. That would pretty much require changing out the bulbs for the winter. During sleeping? Scraping the bottom of the bucket much? I never said that incandescents would eliminate heating, only that it is 100% efficient when used appropriately.
- nkozyra 10y ago
  I think it's a fair point; these bulbs are not used for heating because that's not their primary function (despite being more efficient at it than lighting). The inverse would apply to, say, a fireplace. Light is an acceptable (even desired) side effect of the primary function, but it would not be convenient to rely on it for that side effect.

venomsnake 10y ago

Need a warmish proofing/fermentation chamber - just turn the lightbulbs (2x25W) in your oven on.

kazinator 10y ago

Doesn't work out when heating wouldn't be used, or AC would be. Heating isn't always electric. Using electricity for heating is an egregious waste of a high quality energy source which can do all sorts of useful things besides generating heat.

willvarfar 10y ago

Direct electric is a really inefficient way of heating anything. I ripped out a direct electric heater system and replaced it with a ground source heat pump which is giving 4KW heat for every 1KW electricity (used to run the pump and compressor etc) even in the cold depths of the Swedish winter.

Strilanc 10y ago

You could use the 97% of electricity that was lost to heat to power a heat pump. Heat pumps beat 100% efficiency. [1] > In heating mode, heat pumps are three to four times more efficient in their use of electric power than simple electrical resistance heaters. Instead of just generating waste heat, you generate waste heat and move heat around in a desired way. 1: https://en.wikipedia.org/wiki/Heat_pump https://en.wikipedia.org/wiki/Heat_pump

lutorm 10y ago

Depends strongly on the situation. It's true that where heating would be used, if mounted in such a way that all that heat is available (ie, not recessed into a ceiling fixture), the 97% is useful. (But not necessarily maximally efficient, because if you wanted heat in the first place you'd be better off not turning your energy into electricity, a process with ~50% efficiency at the power plant, and then incurring further distribution losses.) On the other hand, if cooling would be used, it's even less efficient because now you have to cool away all those 97%.

mikeash 10y ago

The electricity for my lights comes from thermal power plants with maybe 40% efficiency and then loses a little bit more in transmission. If I use LED bulbs, then that heat is replaced by my natural gas furnace, which is somewhere around 90% efficient. Net result, even in the dead of winter it saves energy to use more efficient bulbs. In summer, when I'm using electricity to cool my house, the difference is even greater. Resistive heating with electricity is just terribly inefficient. If you have to do it anyway (because you need to run equipment, and that equipment is already as efficient as it'll reasonably get) then you can benefit a little by ensuring that this heat is put somewhere it's wanted. But if you don't have to do it, don't do it. CFLs suck, but LEDs are great. I fear that the CFL interregnum may have hurt the cause of efficient lighting in general.

ars 10y ago
> CFLs suck, but LEDs are great. I have both. There's basically no difference, except the LEDs are hot on the base and CFL's are hot on the bulb. Power consumption is identical, CRI identical, and Cost per Hour (before failing) is basically identical (assuming the hours listed on the package is the truth). > I fear that the CFL interregnum may have hurt the cause of efficient lighting in general. It has not. I've been using CFLs for about 20 years (almost since the day they came out), and they work just fine.
- mikeash 10y ago
  CFLs take longer to come on, don't reach full brightness immediately, are less efficient, don't last as long, and contain mercury. I don't know what your personal statement about using CFLs for 20 years has to do with my fear about the cause of efficient lighting being hurt. Your own preferences don't necessarily reflect those of people in general.
  - ars 10y ago
    > CFLs take longer to come on I have both. That isn't true. I have some LEDs that take longer, some CFL's that take longer, and some (of both) that are effectively instant. > don't reach full brightness immediately Also not true. It used to be that way, and perhaps some poorly designed ones. But there is no reason to buy any that are not instant. > are less efficient Again, not true - make sure to compare bulbs with equivalent CRI. > don't last as long, and contain mercury. This is true, and irrelevant. Also, LEDs cost more, and I'm not (yet) convinced the hour ratings are actually accurate. > I don't know what your personal statement about using CFLs for 20 years has to do with my fear about the cause of efficient lighting being hurt. Your fear is unwarranted. CFLs work perfectly fine, and I know that because I've been using them for a long time.

strommen 10y ago

Sure, but when air-conditioning would be used that equation flips around. Not only do you lose electricity as heat, you need to use more electricity to counteract that heat. And in most places, far more money is spent on cooling than heating. Even in the frozen wastelands of Minnesota where I live, air-conditioning costs over the summer are about equal to heating costs over the winter. As others have mentioned, heat pumps and gas furnaces are much more economical than resistive heating via incandescent lights.

flubert 10y ago
>And in most places, far more money is spent on cooling than heating. Hmm. I've always heard the opposite. Anyway, here's one piece of research. http://iopscience.iop.org/article/10.1088/1748-9326/8/1/014050;jsessionid=7C44E1B7D1A0820B5172272C0C0C55F6.c2.iopscience.cld.iop.org http://iopscience.iop.org/article/10.1088/1748-9326/8/1/0140... "Abstract Energy demand for climate control was analyzed for Miami (the warmest large metropolitan area in the US) and Minneapolis (the coldest large metropolitan area). The following relevant parameters were included in the analysis: (1) climatological deviations from the desired indoor temperature as expressed in heating and cooling degree days, (2) efficiencies of heating and cooling appliances, and (3) efficiencies of power-generating plants. The results indicate that climate control in Minneapolis is about 3.5 times as energy demanding as in Miami. This finding suggests that, in the US, living in cold climates is more energy demanding than living in hot climates."