Dimmer Bulbs

Carbon Element Bulb - On 1/2 Power

Carbon Element Bulb - On 1/2 Power

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(These bulbs are stated to be 220 Volt bulbs but with the “lit” one running at 110 Volts)

Well, just back from buying some more 100 W bulbs before they become black market drug dealer specials. California is going first into this long dark green night, so I’m at the tip of the spear on this in the USA. (Those of you in Australia and the UK and the rest of the EU seem to already “be there”…)

I’ve commented before that bulbs in my dimmers seem to last a very long time. Now I’m going to put some numbers on it.

At Lowe’s, they had a very interesting “bulk box” of 24 bulbs for $10. I bought it. These are Sylvania 100W 130 V bulbs. Note that in America the standard for wall voltage is 120 Vac…

They are ‘dual placarded’ for energy consumption.

120   Volts      130
1700  Lumens    1290
100   Watts       88
750   Hrs Life  1875

So here we get an interesting metric. Reducing the voltage by 10 Vac gives about a 2.5 x lifetime extension.

Most of the time I like about a 60 W to 75 W bulb on full bright for a room (we have white walls, so this works well. With dark walls or furnishings it takes much more). A 67 W “GE Save Energy” bulb makes 1015 lumens at 67 Watts with a 750 hour life. That’s a decent baseline for what I want. The cheapo Phillips 57 w bulb from China ( 19 cents each in the bulk 16 pack at Home Depot ) makes 780 lumens and lasts 1000 hours per the box.

So, IFF I put one of these 130 V 100 W bulbs in my dimmer and run it at about the same output of lumens, in that 1000 ish range, I’m likely to get well over 2000 hours of life from it. I’d guess it’s about a “triple” on the typical hours of a bulb on full power. (Though for some fixtures it will be even longer… The bedroom incandescent is usually run very low so as not to disturb others. When we want a lot of light there, we click on the two CFL bulbs in lamps… so that incandescent has not been replaced in a couple of years, at least.)

That estimate assumes life is roughly linear with delta lumens, but that’s not a ‘for sure’ thing. I probably ought to search for more data on that question, but for now, this is ‘good enough’.

I made an interesting spread sheet out of the data from the bulb packages. I’m not sure all these fields have “utility” or meaning… but what caught my eye was the Lumen-hours / Watt rating field. This is the lumens output multiplied by the hours lifetime divided by the Watts rating consumed at that lifetime. You consume Lumens over a period of hours, so Lumen-hours is what you want.

The 130Vac bulb, dimmed with 120Vac, gives the most Lumen-hours / Watt rating consumed of any of these bulbs by a factor of about 2 to 3. It also has the largest Hr-Watts per Lumen number. (These are reciprocal on Watts and Lumens. So that hr-W/lumen is a kind of ‘total power consumed’ for a given lumen rating while the Lumen-hours / Watt is something of a ‘how much light life do I get for a power rating’ consumption be damned.) While Lumens / Watt is the straight efficiency without weighting for bulb lifetime value.

        	Lumens	Watts	L/W	Hrs	Hr-W/L	L/Hr	L-hr/W
Syl 130V	1700	100	17.0	750	44.1	2.27	12750
        	1290	88	14.7	1875	127.9	0.69	27486
GE 67 ES	1015	67	15.1	750	49.5	1.35	11362
GE 90 ES LL	1450	90	16.1	1000	62.1	1.45	16111
Ph 57    	780	57	13.7	1000	73.1	0.78	13684
Ph 95    	1550	95	16.3	750	46.0	2.07	12237

I note in passing that the Lumens / Watt of the Philips 57 is worse than that of the 130 V run on 120 Vac, but without the great life extension. The GE Long Life 90 seems like the best deal for a non-dimmer use as it has a reasonably long life but with very good Lumens / Watt as well.

Not a real surprise there. The better bulbs last longer while doing a better more efficient job and cost more. FWIW, the GE Reveal bulbs have better color, but at the expense of lifetime and power consumption. Their Lum/Watt is only 12.6 while the Lumen-Hours / Watt is a dismal 9450. It looks like there is a clearly inverse relationship between good looking color and a long lifetime of service.


Dimmers are good at extending bulb life. Anything that reduces the voltage a little would also work, such as putting a diode in the circuit and cutting out 1/2 the wave form. A 25% reduction in lumens output results in a 2.5 Times lifetime extension (though at the cost of some efficiency – roughly 14% less light per Watt).

If you are interested in stretching your stock of incandescent bulbs as long as possible after they are banned, you need to put in dimmers and use larger wattage bulbs run at a lower power setting. This can easily triple bulb life. Lucky for me, I already have the dimmers in place. I want the incandescents largely because they work well with dimmers and CFLs are crap in them.

I’ll be trying a 150 Watt bulb in my dimmer to see just how yellow / red the color becomes ;-)

Visiting Lowe’s and finding those 130 V bulbs is “worth it”. Buying some of the “rugged duty” 20,000 hour bulbs and putting them on dimmers would likely result in a reddish light that would last longer than you will live ;-) h/t to George in https://chiefio.wordpress.com/2010/12/22/curly-bulbs/#comment-10329.

It pays to buy and store the better longer life bulbs.

So what this says to me is that in a misguided attempt to force me to use less energy I am being pushed into a position of consuming far more energy in order to maximize the life of what will now become a ‘scarce good’. All perfectly in keeping with what economics would predict about scarce goods, but not the goal of the Greens.

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About E.M.Smith

A technical managerial sort interested in things from Stonehenge to computer science. My present "hot buttons' are the mythology of Climate Change and ancient metrology; but things change...
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15 Responses to Dimmer Bulbs

  1. E.M.Smith says:

    I just figured out that with my present inventory of bulbs, IFF I get a triple life out of them via dimmers, I’ve got just under a 30 year supply.

    I won’t get that kind of life from some of them (the 57 watt energy saver, for example, will need to be run full bright to be usable) but it’s a decent planing benchmark.

    I’ll probably buy another box or two of the 130V bulbs if I happen to be in the store, and I’m going to pick up a half dozen of the 150 W bulbs for the “hail Mary” last ditch cupboard (just in case “someone” decides to share the main stock with friends and family…) and I’m going to try ordering some of the 20,000 hour bulbs just to see if they have any decent light quality at all.

    But the bottom line is that, with the expected life extension from higher wattage bulbs run on dimmers, I ought to be “set for life”.

    I’d rather run the bulbs in a more efficient mode and just buy new ones when they burn out; but the Green Nazis have decided I must be far less energy efficient.

  2. Curt says:

    My impression is that it is the new “smart” dimmers that gradually turn on bulbs that are the key life extenders. Light bulbs invariably fail on turn-on, and their life is more dependent on the number of on/off cycles than on time on. I don’t think that the steady state power is that much of an issue.

  3. KevinM says:

    LEDs can be better in every way but cost. Cost is unreasonable, but in a few years it will work out.

  4. E.M.Smith says:


    The “inrush” current is higher as the filiment is cold. That usually “blows” the thinnest part of the element. BUT the thinning happens from steady use evaporating metal.

    The “longest life” usage profile is: Minimal hours ON. Gentle ‘turn on’ over a few seconds – any dimmer with a ‘slow on’ does this. Run at less that full power (cooler element evaporates less in use). It’s all just the physics of evaporating hot metal and electric flow through hot vs cold wire.

    @Kevin M:

    Looked at some today. $30 for something the equal of a 20W bulb. Nothing on the shelf close to the output of a 100W bulb. Some 40W equivalents. One looked to be about a 60W equvalent, but was $60 and a flood light shape.

    They did say they worked on dimmers, but I could find none that needed to be more dim…

    Oh, and they all said, basically “Don’t even think of putting this outside in the weather or where it might get wet”.

    So I’m still waiting on that first LED bulb…

    Most of my flashlights are now LEDs. Light is a little “odd” in color with a bluish cast and mottle to the CRI over the area of light. I’d hope the home use ones have a better CRI and more uniform color.

    Maybe after I’ve bought another $30 of 100W incandescents I’ll buy my first in home LED bulb… Odd that, yet another way that the “ban” is having backwards impacts. IF they were not pushing me into making an inventory of 100 W bulbs, I’d have the “mad money” for lighting experimentation and would have bought that LED bulb today. I had $30 in hand for “lighting”, wanted to “play with” that LED bulb, but the ban ment it was directed into incandescents….

  5. John F. Hultquist says:

    On this and many other issues there are a great number of people that haven’t a clue that people can and will make choices that inflict great damage on the goals others try to impose. The “death tax” issue is one such.

    Your dimmer switch is a great and simple solution and I’ve used it in a few places. When the CFLs were on sale at COSTCO I bought a package of a dozen. Out in the barn, I put them in the sockets protected behind a barrier in hard to reach places where I need light to feed in the early morning or evenings in winter at 47 degrees North. When the temperature is low they are still warming up as I finish, so I just leave them on day and night. When they give up I will go with the dimmer switch out there or just back to the double life type.

    KevinM mentions about LEDs – “in a few years it will work out.” These are being improved and the cost will come down. Also, there will be other technologies. The following link will take you to a company with a different concept:
    Full disclosure:
    I own a small amount of stock in this company:

    Their bulbs are just now coming into production and are costly.

  6. Ray B says:

    One thing that concerns me about hoarding bulbs is my paranoid fantasy that Big Brother will somehow be able to pick up on their use.

    Will Gen 2 or a firmware updated smart meter be able to say ok, this is a lighting circuit, it is drawing power, but I am getting no line noise from a ballast (CFL) or a power supply (LED), time to call the feds in?

    Will they have cops flying over houses with an IR camera looking for people like me committing felonious bulbcrime like they do the dope growers?

    Beyond my paranoia, thanks for the comparison and analysis. For a guy like me slowly stocking up lots of bulbs it is handy.

    Your friend in bulbcrime-


  7. gnomish says:

    some of the processes involved in luminescence must have a wear/load curve that goes exponential- and perhaps the ‘maximum rating’ is set to avoid the steep part of it.

    i used to regale the innocent and unwary with a MTBF (mean time between failure) chart for some IC (integrated circuit) i was in love with at the time which showed about 100,000 hours at maximum rating; at half max rated power, the mtbf was 4.5 billion years.

    anyway, it makes sense that a dimmed bulb should burn longer than one maxed out.

  8. E.M.Smith says:

    @John F. Hultquist:

    Got a stock ticker? It looks interesting from several points of view…

    The technology looks sound, the product looks like it ought to be robust. If it can out quality the CFL and under price the LED it ought to be a winner. The “fully dimmable” caught my eye. I’d pay a farely large amount for a truely dimmable (and smoothly even down into the lower ranges you use when someone else is asleep in the room…) efficient bulb that didn’t flicker or hum. “OK” color rendering index or better would be a ‘plus’. Let me know when they are available for sale. I’ll buy one just to product test it.

    @Ray B:

    It would be fairly hard to detect an incandescent bulb remotely. Electrically they look like any resisitive element (as they are). Toaster, oven, room heater, aquarium heater. There is a minor difference from electronics power supplies (they have various inductors and capacitors in them so the ams vs volts can lead or lag) but detecting that remotely inside a building would be hard to do as there are a lot of different things plugged in at any one moment and trying to unscramble those eggs would be a fools errand. For example, a pure inductive load will be offset by a capacitive load (that’s why the power company puts large capacitors on the power poles, those grey cans that are not transformers and ohly have 2 or 3 leads). So you could not tell a pure resistance from an inductor / capacitor well matched set.

    Oh, and if it will sooth your mind: The dimmers are an electronic device so do not look like a ‘resistive load’ to the wiring. Any bulb downstream of a dimmer looks like electronics. It makes the same kind of ‘switching noise’ on the line as a CFL electronic ballast. Put a bulb downstream of a transformer and it looks like a magnetic ballast CFL.

    My ultimate “Hail Mary” on incandescents is exatcly that. I have a modesly large 12 VDC transformer (i.e. car charger) and will just use automotive bulbs on a 12 VDC curcuit if I ever really need to “go there”. At one time I had an old car headlight where the “low beam” had burnt out. I was building a workbench in the garage at the time and have 12 VDC ‘plumbed’ to it. Just hung the bulb over the bench and it’s still there as my ‘work light’. I’m using a normal wall swith to control it. Works very well. Unfortunately, I’m accumulating “1/2 burned out” headlights faster than they get used up. I think I need to spend more time at the work bench ;-)

    Per “smart meters”: I’ve got one. It does not “sense the house”. It’s mostly just a radio link to the billing department so they don’t need folks wandering in my yard to read it. They haven’t even gotten to the stage of being able to shut off power to a single major appliance (like a clothes dryer) and IMHO won’t succeed if they try. I’ll never pay for it and they will have “trouble” trying to force it on me.

    Per heat detection: M.J. grow rooms want to run at about 100 F and use several kW / room. The temperature anomaly is Way High for the Whole House. Use of a bulb is a single point source of 100 W and folks generally don’t let the room run up to 100 F in the winter…. It would take, well, a few kW / room, and not 100 W. Further, if IR imaging a place, you would find every 100 W scale ‘hot spot’ in it. That Aquarium, for example, and that 200 W DVD player along with the decorative candles and the “vaporizing room deodorizer”. Oh, and you. You are about a 100 W source…

    Now, that would take a great deal of money and equipment to do, and almost entirely result in folks trying to raid and arrest Ms. Muppet and her Tropical Fish or Granny under the electric blanket and SWIMBO and the bathroom Heat Lamp. No sane politician would try it, and any that did try it would soon be BBQd by the public.

    So “Store in peace” my friend. They are depending on the tendency of 90% of the people to be clueless sheep and once supply is cut off will have all they care about. No policing expense needed.


    Yes. The filiment slowly loses mass from evaporation. This is not even, so one part thins a bit more than the rest. This is now a ‘choke point’ for the electrons and it gets a little hotter, so evaporates faster, so thins quicker. Repeat until one day the ‘cold inrush current’ causes it to vaporize in a “SPFUNT!” flash. You can make that exponential moment come much much later by buying good quality bulbs (with more uniform filiment construction), running them a bit dim (so they evaporate much more slowly), and applying the start up current slowly (in bulb time: 1 second instead of 1 milisecond) so the element can warm up and have resistance increase along the whole filiment thus preventing the large ‘inrush current’ from popping the ‘weakest link’.

    Making the bulb a bit dim can be done with dimmers, diodes, reduced mains voltage, a higher bulb voltage design rating, a whole load of things.

    BTW, on AC the filiment has a physical vibration mode that can also fatigue the metal. The “filiment supports” can reduce this, so the “rugged bulbs” for 20,000 hour use have a fatter filiment (dim bulb) but also better supports. You can extend bulb life by the expedient of running them on DC as it only has a “magnetic flux moment” at startup, not 60 times a second….

    For ultimate bulb lifetime, run them on 100 VDC ;-)

    The “bulb rating” is a design point chosen for best long term benefit assuming you can easily and cheaply replace the bulb. Longer life comes from less lumens / watt. Those long life bulbs are not as efficient. So for remote fixtures that take a 2 man crew and lift truck to change the lights, you put in long life and cost of electricity be damned. Now, every fixture is a ‘hard to change’ one and all of them deserve the lousy efficiency but long bulb life design point.

    Personally, I’m just gonna buy 100 more at 19 cents each… and skip 3 or 4 Starbucks…

  9. Gary P says:

    I was an early adapter of CFL’s and put them in where ever they made sense. I did find that the slow warm up of the CFL’s can be fixed by going to a brighter bulb. When replacing a 60 watt incandescent, use the 75 watt CFL equivalent. It still will use less than 1/3 the power.

    My living room has large, south facing windows so I do not use lights much in the summer. In the winter, I turn on all the incandescent bulbs in that room to warm it up with a couple hundred watts of power. This is cheaper than keeping the whole house warm. I suppose when I run out of bulbs I’ll need to buy an electric heater. Unfortunately, 200-300 watt heaters are not available so I’ll probably be stuck with a 750/1500 watt heater that will need a noisy fan to spread the heat through the room.

    What’s wrong with freedom?

  10. E.M.Smith says:

    @Gary P:

    I have 600 / 900 / 1500 W (two switches , three settings) oil filled heaters in each bedroom (so folks only heat where they are if the whole house heater is off.) Delonghi brand.

    Work well, last forever, nearly silent. Convection distributes the heat nicely. Part of why I like them is that, being close to the floor, they heat the ‘low cold’ layer and move it up. The household ‘forced air’ is all from cieling vents. Great for AC but lousy for heat… it warms the house down to about the 5 foot thermostat height then shuts off ;-) Can you say stratification? Inversion?…

    At any rate, one of these is usually left running even when the gas heater is warming the whole house, just to get the cold foot level air moved around… IIRC the last one I bought (for Granny) was about $45 at OSH or Home Depot.

    They look like an old fashioned radiator…


    it looks like they have an “inventory issue” notice up. Sears has them too:


    looks like the current model. Mine are about 25? years old. Got them when we first had kids and put in the bedroom then. Still sitting next to me know, though the kid is graduated and moved out …

    Yeah, I like them…

  11. tckev says:

    For years I used dimmable, very high brightness, 150W halogen bulbs with soft-start electronic dimmers. Yes at 3-4 times the cost of ‘normal’ incandescent bulbs they’re not cheap. However they had fantastic light both in color and brightness – no premature red/orange at lower dimmer setting. Great for reading and normal use, plus these bulbs (Sylvian/Phillips made in Poland) lasted 3-5 years with normal everyday use on the dimmer. These bulbs had normal ES base, with the halogen capsule held within a normal shape glass envelope.
    They were always difficult to find but in the last few years its become impossible. Other brands do not have the brightness or wattage rating, and the Chinese/Far East look-a-like versions barely last a year. Have the eco-Nazi ensured their demise?

    So what is left?

    Incandescent bulbs are inexpensive and reputable brands have very reasonable lifetimes when use with a dimmer. Really bright ones are getting harder to find (100-150W). I like the no ‘warm-up’ time; switch ’em on they’re on. IMHO they seem quite orange when dimmed but are OK for reading.

    CFL are dull, soft, flickery, shadowless light that seem to take for ever to warm-up to peak output. I have tried many brands/types with various “equivalent Wattage” rating and IMHO all are terrible lights. Useless for reading and it gives me headaches. Also the expected lifetimes are a joke!

    LEDs are far too expensive for general use but this is a rapidly changing new market and they do have ‘expected’ life of 30,000hrs+.
    I’ve bough three of them ($28 each) and put them in as spot lighting in to provide reading/close work lighting where needed. These LED bulbs are 9 Watts bulbs, using 7 pcs 1.25W high power LED, with 180 degree beam, light output 500 lumens, comparable to 60 watt incandescent bulbs, daylight white 4500~5000K, and work ambient temperature -40~45℃. They appear MUCH brighter! more like a 100W of cool bluish non flickering light. Great reading lights!
    However the internal controller sound complicated and stops them being used with a dimmer. The input voltage range of 85V~265VAC, a built-in constant current supply, with over-load, over-voltage, over-current, over-heat protection. I expect this ‘feature’ to be the weak-link.

    For the government view of expected lifetimes see here

    @John F. Hultquist those bulbs look like they could be a good bet (in both senses).

    And finally, for years one guy and his son has struggle to find a better answer but for the want of money…

  12. John F. Hultquist says:

    As I mentioned the Vu1 bulbs have just become available on a limited basis. They want $20 each and a minimum of 8. The stock is cheaper so I bought it. If the hype is true the bulbs will sell, the price will come down, and then I’ll buy a case.
    Have a look at this page.


  13. John F. Hultquist says:

    Just read your note about the Delonghi oil filled heaters. I use those as they are safer than almost any other little heater. In Washington they can be bought at Bi-Mart. They use them as sale items so wait for that.

  14. E.M.Smith says:


    So for decades we’ve been beaten about the head and shoulders with the WTO saying that this and that local law would not stand up to the WTO requirement for unbiased fair trade.

    I’ve got to take tuna with mercury and killed dolphins.

    I’ve got to take Chinese toys with mystery metals in the paint.

    Well, how about this:

    Bans on the importation and sale of incandescent light bulbs violate WTO trade rules in that they unfairly penalize those economies who can’t make LED lights or curley bulbs.

    They restrict the free trade in Edison Bulbs unfairly.

    Anyone know how to file a WTO complaint?

  15. Jeff Alberts says:

    “Bans on the importation and sale of incandescent light bulbs violate WTO trade rules in that they unfairly penalize those economies who can’t make LED lights or curley bulbs.”

    Then we must give those countries billions of dollars so they can make their own! Social Justice!

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