incandescent bulbs

Cecil's Columns/Staff Reports
61

I think that would depend on the design - ideally, it shouldn’t generate any excess waste heat - after all, that’s energy consumed that isn’t lighting the room.

But there are some terrible LED bulb designs out there - I just bought a couple of them from China (yeah, I know) - and took them apart - they were almost identical except that the UK 240V version had a great big resistor in addition to the (rather rudimentary) rectifier/smoothing circuit. I shot video of the teardown - I’ll post it later.

All electronic devices will generate some waste heat, but what we need is a design that doesn’t just throw away energy in order to make the design simpler.

62

Cecil didn’t say that (and thus, only neglects your girlfriend in your trimmed quote version). He said::

If you’ve got vision problems that are aggravated by CFLs, then that’s a situation when you couldn’t.

63

A properly made LED bulb will use a switching power supply, which can be 90% efficient, however, most of the heat is still lost in the LEDs - even the very best LEDs are still only around 20% efficient and you’ll only find those in more expensive bulbs. As an example, for a 9 W bulb, power conversion at 90% efficiency will loose 0.9 W, leaving 8.1 W for the LEDs, which at 20% efficiency dissipate 6.5 W with 1.6 W of actual light output. Also, a lot of the heat dissipated by an incandescent is infrared (that is why you can feel the heat before the bulb feels hot), whereas in LED bulbs it is almost solely conduction/convection.

Those cheap designs that just use a bridge rectifier can actually have pretty low power loss, less than a SMPS (but a terrible power factor and no regulation) IF a capacitor (in series with the power line) is used for its capacitive reactance; using a resistor is about the most inefficient thing to do if most of the voltage is being dropped across it (however, LEDs don’t like being pulsed at high current, which this design will do, increasing power loss in the LEDs and decreasing lifetime).

64

I started using CFL ten, maybe fifteen years ago. They’ve been continually improving in color, startup, and life (both average life and infant mortality). I had a couple of inherited lamps dating to the 40s or earlier that needed new harps, and one clip-on shade that needed to be replaced with a harp and shade (but it needed a new shade, anyway), but that’s all. It’s true that, because they are not black-body radiation, they can be deficient for certain technical purposes, but in the real world, most of those technical uses reside in commercial buildings that were being lit with fluorescent tubes before I was born. (Now that I think of it, one chem lab on a site I worked at solved the problem by simply using clear-glass windows for real sunlight.)

65

So let’s say I want a night bright-white CFL floodlight that is an instant on. What should I look for on the box when I go into the local Lowe’s or Home Depot? I got some to replace the lighting in my kitchen and besides not being instant on, the level of lighting seems a bit dim even after a few minutes.

66

the harps mentioned by John W. Kennedy are the rod that holds the shade above the bulb. if your harp is too small to accept a CFL then you can buy harp extenders at hardware stores; a small metal part that moves the harp wider, most harps and lamps can accommodate them.

67

Having just been shopping for lights at Home Depot, my opinion is that you really don’t want a CFL, you want an LED. They’re finally about ready for floodlight use (since LED’s naturally throw light in one direction; this is easier for LEDs than send-light-in-all-direction table lamp bulbs).

The EcoSmart brand at HomeDepot is pretty good – mostly 2700K color, which is pretty close to incadescants. If you don’t care, there might be slightly cheaper bulbs at 3000K color, which is slightly blue-ish if you compare side-by-side, but you might not really notice with a single bulb. More expensive than an incadescent bulb, but I did the math myself on a couple of overhead light fixtures, and the LEDs paid for themselves in about five years just on the lower electric costs. Which is pretty good – if you have any investments reliably paying 20% a year, you should take them!

68

A halogen bulb with similar Lumens to the bulb you are replacing. Instant On is not a case for CFL.

Brightness is in lumen count. “Temperature” affects the color/hue. CFLs look bluer/whiter than incandescents which seem more yellow.

69

Actually, IR heating (which is what incandescent bulbs are) is extremely efficient.

Good luck getting consumers to mix-and-match bulbs this way. I’d go all halogen, myself. Wonderful lights, those halogens.

Most consumers don’t read the lumen values, they read the “equivalent” values. They know what a 100W bulb looks like, but they don’t know how many lumens it puts out. Plus, as I stated before, these bulbs get much dimmer over time, losing 50% of their efficiency by the time the “die.”

I’m not talking about the color temperature, I’m talking about the Color Rendering Index. Color rendering index - Wikipedia

Low CRI lights, such as CFL’s, output light that is 15% or more “wrong.” There are weird peaks and valleys in the output. Colors look off. Your mind perceives something is weird, but you can’t quite figure it out. It’s unsettling.

The only high-CRI fluorescents are the big tube lights. CFL’s are pretty bad.

“White” LED’s are even worse. They’re great for flashlights, but awful for room lighting.

Color management is one of my skills as a professional photographer. I know a lot more about light than the average person.

70

We tried CFs for about a year. Biggest mistake we ever made. The cost difference was huge – 7-8 dollars each compared to $1.50-2.00 for a 4 pack of incandescents. And the lifespan? At BEST slightly less than incandescents. On average about half as long. The only way they could have been cheaper in the long run would have been if our electric bill had been reduced to zero, and maybe not even then.

I have since found out that they don’t do well in recessed or enclosed fixtures. Well, that pretty much just leaves the laundry room.

71

That is only true for the heating element; any resistive heater is 100% efficient in converting electricity to heat (97-98% for incandescents, excluding visible light, which also counts if it is all contained inside the house). But what about the process that generates electricity? Not even close to 100% efficient. More like a third of that in fact, while a modern gas furnace can be in excess of 95% efficient, even older furnaces are still much more efficient (some combined-cycle gas plants can achieve 60% efficiency but that is still a big loss, plus they have to pay for the gas and that, along with operating costs, goes into the electric bill you pay).

72

I found that incandescents- esp. candle bulbs- blew after a few weeks if mounted upside-down in e.g. a chandelier. CFLs lasted far far longer. Presumably this is bacause convected heat cannot escape so readily with an incandescent. Up until the advent of LEDs every bulb in the house has been a CFL. My only grouch is that the light is too “soft” for reading by. That’s no problem with an LED. As my CFLs burn out they’ll be replaced by LEDs. As I mentioned before, they’ll outglow me now I’m in my 60’s!
P.s. Cheap CRFs of an unknown make are hopeless- buy Phillips GE etc.

73

We already consider wattage, bulb size and shape (flame shaped instead of standard, appliance bulbs vs regular, night light, etc), plus special bulbs for flood lights (like the ones in my bathroom). It is not that hard to also account for the difference between a standard room light and a quick on/off location like a closet.

74

Cecil makes good points. He does indeed seem an intelligent being!
I would expand on some of those points

  1. Regulations
    The US, EU and most other standards will
    effectively ban all ordinary incandescent lamps
  • including the touted halogen replacements, as from the US EISA 45 lumen per W end regulation standard (halogens typically 22-25 lumen per W)
    Standards explained, and 10 American state repeal ban bill updates (legislated Texas) Light Bulb Clarity: New Electric Politics
  1. Savings
    All lighting has advantages, energy saving is not the only reason to choose a bulb.

Besides, light bulbs don’t burn coal or release CO2 gas.
Power plants might.
If there is a problem - deal with the problem :slight_smile:

While individuals may save on some frequently used bulbs,

  • noting that not all bulbs in a typical 45 light US household are used much, and remembering about breakages, lost bulbs etc -
    overall US energy savings from a switchover are a fraction of 1%,
    based on US Dept of Energy stats and surveys, referenced
    Light Bulb Clarity: New Electric Politics
    also describing more relevant electricity generation, grid and home consumption savings.
    Even when individuals save more, society energy measures should of course be based on supposed society savings, unless interfering with individual lives is a priority.
    And individual citizens don’t save as much as they might think…

So, re Dangab original post on Heat,
while 95% of incandescents is indeed released as heat, it is at least usefully radiated (when it’s dark it’s often cold!)
Light Bulb Clarity: New Electric Politics research referenced
Conveniently ignored:
80% of CFL and 70% of LED energy is more truthfully “wasted as heat”,
since their heat is internalized, giving a greater less predictable fire risk, especially with CFLs (http//ceolas.net/#li18eax )

  • yes, incandescents can burn lampshades etc, but that is more noticeable and predictable.
    Moreover, the “power factor” of CFLs alone means that they use twice the energy to what your meter says, as Sylvania/Osram admit in the linked factsheet
    (many domestic LEDs also have power factor issues)
  • but users will of course have to pay for that eventually.

Again as Cecil says,
Jevons paradox about using more of effectively cheaper usage, should be remembered.

Conversely,
energy saving does not necessarily save money either.
Electricity companies are allowed to raise prices, or be taxpayer-subsidised, for expected lower electricity sales as referenced on the website (California, Ohio. etc CFL switchover state programs, as in Europe, UK, Canada, BC etc)
Re **Dangab **on CFL manufacture energy use,
there is some data online for example from Osram purporting to show relatively low manufacture energy use.
However, that relates to assembly of manufactured components.
As linked, German Dr Stanjek in research for Greenpeace (so hardly biased) pointed out that the real energy use is several multiples of times more than pure assembly.
A real overall comparison would also take into account the energy/environmental cost of mercury mining, ballast component sourcing and manufacture, CFL manufacture in China using inefficient coal plant energy source, transport from China on dirtily bunker oil (C02, mercury releasing) powered ships, recycling energy cost and in some cases transport back to China for re-assembly etc, similarly as appropriate with LEDs.
Certainly, incandescent manufacture is not always local, but more easily so, also for low-tech startups.
Incidentally - since Cecil mentions it -
no power plant would be spared even on supposed savings, certainly not any major coal or similar plant- it relates to the constant base load from such stations.
It is a bit like saying “Hey, if we reduce pupil numbers, we can reduce the number of schools built!” - but of course 70-80 rather than 100 pupils in an area still means essentially the same school facilities are required (and here it is more like 99 rather than 100).

75

RE the “old obsolescent” criticism of regular incandescents,
as by Cecil:

“incandescent light bulb, though surely up there with the telephone as Coolest Invention Ever, has like old rotary-dial phones been rendered obsolete by advancing technology. It’s one of the least efficient devices you’ll ever lay hands on, converting just 5 to 8 percent of the energy it uses into light, with the rest thrown off as heat”

Here I would disagree (though Cecil does later seem to add that nanny state bans are still wrong)

  1. The heat is not necessarily wasted, as covered before.
    When it’s cold it’s often dark. The wrong criticim in this regard is that
    bulbs are inefficient as heaters. Irrelevant, because they are of course used for their light, the heat is merely a side-benefit, albeit valuable, as researched Light Bulb Clarity: New Electric Politics
    Conversely, any use in working against air conditioning cooling is of course optional, and might still be preferred on light quality or other grounds.

  2. Rotary dial phones (or say vacuum tubes)
    weren’t banned just because touchpad phones or transistors, came along…
    Moreover, there may be residual limited but appreciated advantages of superseded technology - usable if it’s still allowed
    Not sure about rotary dial phones, but say “horse and buggy”, or vacuum tubes still have appreciated uses (any guitarists out there :wink: )

  3. Precisely from being "old" the incandescents are also well known,
    relatively safe technology
    Ironically, the push is to replace them with complex questionably safe
    mercury etc containing alternatives
    (ironic, because product bans used to be on safety grounds, eg lead paint!)
    Welcoming the new does not mean having to ban the old

  4. There’s also the strange notion,
    that energy saving is the only good quality a product can have.
    Incandescents have many advantages, and pushing energy saving on them, as with other products (buildings, cars etc) compromises some of their characteristics (eg temporarily allowed halogens, have a different light quality etc apart from costing much more for marginal savings)

  5. Efficiency is not just energy efficiency.
    There is no more **efficient **way to make bright lighting for ordinary omnidirectional household use, than incandescent technology.
    In that regard, the early ban on simply made 100W bright lighting makes little sense.
    It is much harder and more costly to make bright CFL or LED lighting.
    ( US regulations are even paradoxically based on lumens - not wattage.
    That is why any bright 75W bulb is banned 2012, regular dim 75 W bulbs in 2013)
    And, since this often comes up, might as well throw it in:

6.Innovation
CFLs and LEDs were invented in the presence - not the absence- of cheap incandescent competition.
More - not less- competition is what spurs development, also of desirable energy efficient products. that people have always invented, as that is a positive product quality (although not the only advantage a product can have for a user)
Plenty of other “expensive to buy but cheap in the long run” products are bought - look at Energizer batteries (bunny ads), washing up liquids etc. Those makers don’t run crying to the regulators, looking for bans on cheap “wasteful” alternatives.
All about the Deception behind the Ban:
http://freedomlightbulb.blogspot.com/p/deception-behind-banning-light-bulbs.html

76

Hang on a cotton-picking minute Lighthouse! What is the difference between a bright and a dim 75W bulb-unless it’s just the space between the numbers and the letter. Cannot puzzle out your argument at all. Apart from specialist applications, incandescents and CFLs will join the candle in the dustbin of history in a few years’ time, as like the car and the computer, LEDs can only get cheaper and more efficient with time.

77

Well, his linked adress says it all: Freedom for light bulbs!

Who can argue against freedom? (Why do you hate America? :))

78

75W (or 75 W) refers to how much power it uses, not how much light it emits. The amount of light is measured in lumens. A dim 75W bulb uses the same energy but gives less light than a bright 75W bulb.

79

That doesn’t explain why they are banned at different times. What distinguishes them for the purposes of banning?

Seems like the brighter ones are more efficient, and thus should be the later ones banned, if anything.

80

Nicely put Constanze!. I would like to confirm that, although a tiny majority of us Brits may not always be totally in favour of everything America does, a very vociferous few- about six of us, I think- are in favour of complete freedom for light bullbs and are quite fond of the US.
Rating bulbs in lumens is a new concept for the general public . It will take donkeys’ years before it is as comprehensible as incandescent wattage equivalent is now. As I said in my first post (how long ago that seems!) it appears Watts should be divided by app. 3 to convert to lumens-and both should be displayed prominently on the packaging for at least the next 50 years.