"kind defeats the purpose of saving electricity"

To save electricity you dont need lamps, or even wiring to them

When you need the light, use the power that it takes to make this light

 - One thing is being really wasteful, trying to illuminate a workroom in the garage with the "botique style" underdriven Incandescents at 2000K color temp and <5 Lm/W

 - Other thing is using ANY fairly enough efficient lighting. Everyone seems to forget that the step between different types of energy saving lighting (that includes ALL FL) is not that huge... ~50 Lm/W "worst old Fluorescents" vs 80Lm/W brand new typical LED panel troffers. Its nothing like the difference of 15 vs 50 (normal Incanescent vs worst Fluorescent). More often than not, its not the power difference worth bothering about

"kind defeats the purpose of saving electricity"

To save electricity you dont need lamps, or even wiring to them

When you need the light, use the power that it takes to make this light

 - One thing is being really wasteful, trying to illuminate a workroom in the garage with the "botique style" underdriven Incandescents at 2000K color temp and <5 Lm/W

 - Other thing is using ANY fairly enough efficient lighting. Everyone seems to forget that the step between different types of energy saving lighting (that includes ALL FL) is not that huge... ~50 Lm/W "worst old Fluorescents" vs 80Lm/W brand new typical LED panel troffers. Its nothing like the difference of 15 vs 50 (normal Incanescent vs worst Fluorescent). More often than not, its not the power difference worth bothering about

I thought underdriven incandescents were more efficient.

I thought underdriven incandescents were more efficient.

No way. And the dependence is very steep: A lamp powered at 50% power (via dimmer,...) gives off barely 25% of the light compare to the full power operation. With 10% power (so about 25% rms voltage) it is just some percent or so, with the typical 5% minimum power settings for the dimmers (so about 10..15% voltage) it means way below 1% of the light output.


Even a normal incandescent temperature means the radiation peak is in the IR, the visible is reached only by the "tail". And in that "tail" is really just a small part of the radiated power, that is the main reason for the generally low efficacy.
But when you reduce the power, so the temperature, the peak shifts deeper into the IR (beside becoming generally lower), so way smaller part of the "tail" remains in the visible, so the radiated power in visible gets way smaller, so the already low efficacy gets way lower.

This is the main reason, why all lamp designers tried to increase the filament temperature as much as possible without shortening the life too much.
It is the main reason, why incandescents are designed for just 750 or 1000h life and not longer: Longer life requires lower operating temperature and that means lower efficacy.
Exactly the same reason is, why the halogens are more efficient: The internal chemistry greatly slows down the filament evaporation, so it allows it to be operated hotter for the similar (or even slightly longer) operating life. It is the higher temperature, what makes the lamp more efficient.
All are optimized to a minimum overall cost of the light, even counting for a penalty for the lamp failure and replacement work.

So if you intentionally underdrive the lamp, you waste all the effort made to boost the efficacy. So you may boost the life to 30+years when operating at 50% power, but you lowerr the efficacy to about one half or so. So for the same light you need twice as high real power. Well, with present bulb and electricity costs, it means your light becomes twice as expensive compare to when operate the lamps at rated power and replace them once a year (assume "standardized" cycle).

So all the "buttons" and "long life lamps for home use" may increase the lamp life, but cost a lot on the lamp efficacy, so are nothing more than just a false economy scam.


And the lowering efficacy at lower power is the main reason, why it is so difficult to make the dimmable LED ballasts compatible with the incandescents, mainly to ensure the dimmer operation: It means where the incandescent consumes about 10% of the full power, so 10W instead of 100W, the LED consumes about 1% of it's full power, so about 0.15W or so (assume 15W LED as a replacement for a 100W incandescent). Well, the ballast will for sure operate well with a 10W load, but the 0.15W is really not manageable via triacs... Therefore the dimming range uses to be limited to about 5..10% of the LED power, what means about 10% of the light output. But that equals to the incandescent operating at about 30% power settings, far from the minimum...

Quote from: wattMaster on June 09, 2016, 09:13:49 PM

I thought underdriven incandescents were more efficient.

No way. And the dependence is very steep: A lamp powered at 50% power (via dimmer,...) gives off barely 25% of the light compare to the full power operation. With 10% power (so about 25% rms voltage) it is just some percent or so, with the typical 5% minimum power settings for the dimmers (so about 10..15% voltage) it means way below 1% of the light output.


Even a normal incandescent temperature means the radiation peak is in the IR, the visible is reached only by the "tail". And in that "tail" is really just a small part of the radiated power, that is the main reason for the generally low efficacy.
But when you reduce the power, so the temperature, the peak shifts deeper into the IR (beside becoming generally lower), so way smaller part of the "tail" remains in the visible, so the radiated power in visible gets way smaller, so the already low efficacy gets way lower.

This is the main reason, why all lamp designers tried to increase the filament temperature as much as possible without shortening the life too much.
It is the main reason, why incandescents are designed for just 750 or 1000h life and not longer: Longer life requires lower operating temperature and that means lower efficacy.
Exactly the same reason is, why the halogens are more efficient: The internal chemistry greatly slows down the filament evaporation, so it allows it to be operated hotter for the similar (or even slightly longer) operating life. It is the higher temperature, what makes the lamp more efficient.
All are optimized to a minimum overall cost of the light, even counting for a penalty for the lamp failure and replacement work.

So if you intentionally underdrive the lamp, you waste all the effort made to boost the efficacy. So you may boost the life to 30+years when operating at 50% power, but you lowerr the efficacy to about one half or so. So for the same light you need twice as high real power. Well, with present bulb and electricity costs, it means your light becomes twice as expensive compare to when operate the lamps at rated power and replace them once a year (assume "standardized" cycle).

So all the "buttons" and "long life lamps for home use" may increase the lamp life, but cost a lot on the lamp efficacy, so are nothing more than just a false economy scam.


And the lowering efficacy at lower power is the main reason, why it is so difficult to make the dimmable LED ballasts compatible with the incandescents, mainly to ensure the dimmer operation: It means where the incandescent consumes about 10% of the full power, so 10W instead of 100W, the LED consumes about 1% of it's full power, so about 0.15W or so (assume 15W LED as a replacement for a 100W incandescent). Well, the ballast will for sure operate well with a 10W load, but the 0.15W is really not manageable via triacs... Therefore the dimming range uses to be limited to about 5..10% of the LED power, what means about 10% of the light output. But that equals to the incandescent operating at about 30% power settings, far from the minimum...

Whoops, I forgot  that incandescent lamps are a black body radiator.

And what about the equivalence game with household LED bulbs?
Is it that the big LED makers don't want to be caught?
Another thing stopping foolish equivalence ratings are big signs you sometimes see at LED bulb shelves, that says "You used to measure light output in watts. You now use lumens." or something like that.
And why don't the Chinese ebay lamp sellers get caught?
Or what about lighting with 5mm LEDs? How about the "Superflux" kind?
Another thing is, when I posted about why RGB LED arrays have low CRI, and after I read why, I wondered:
"Why not add more LED colors? There's a practical rainbow of them." and would that work?
It would have more lines for more color rendering, so it should be good.
But what would the efficiency be?
That's a lot of questions, but more answers means more info for LG.net
And one more thing, the old fuorescents had a LP/W of about 35, the Beryllium tubes.

And what about the equivalence game with household LED bulbs?
Is it that the big LED makers don't want to be caught?
Another thing stopping foolish equivalence ratings are big signs you sometimes see at LED bulb shelves, that says "You used to measure light output in watts. You now use lumens." or something like that.
And why don't the Chinese ebay lamp sellers get caught?
Or what about lighting with 5mm LEDs? How about the "Superflux" kind?
Another thing is, when I posted about why RGB LED arrays have low CRI, and after I read why, I wondered:
"Why not add more LED colors? There's a practical rainbow of them." and would that work?
It would have more lines for more color rendering, so it should be good.
But what would the efficiency be?
That's a lot of questions, but more answers means more info for LG.net
And one more thing, the old fuorescents had a LP/W of about 35, the Beryllium tubes.

The equivalence thing is not a game. A 60w incandescent bulb gives out 800 lumens on average. So a led bulb that gives 800 lumens as well would have 60w equivalent on the label. Same thing CFLs have been doing for years.

People are familiar with 40w, 60w, 75w, 100w, and so on. So it makes sense to say this LED/CFL is equivalent to this bulb but uses less energy to produce a certain amount of lumens. Nothing to do with makers "getting caught" or some tinfoil hat BS like that.

Changing the "measure light amount by wattage" to "measure by lumens" in stores will confuse a lot of people. So if they ever do that they'll have to transition the lumens in and incandescent watts out slowly.

Quote from: wattMaster on June 15, 2016, 08:00:32 AM

And what about the equivalence game with household LED bulbs?
Is it that the big LED makers don't want to be caught?
Another thing stopping foolish equivalence ratings are big signs you sometimes see at LED bulb shelves, that says "You used to measure light output in watts. You now use lumens." or something like that.
And why don't the Chinese ebay lamp sellers get caught?
Or what about lighting with 5mm LEDs? How about the "Superflux" kind?
Another thing is, when I posted about why RGB LED arrays have low CRI, and after I read why, I wondered:
"Why not add more LED colors? There's a practical rainbow of them." and would that work?
It would have more lines for more color rendering, so it should be good.
But what would the efficiency be?
That's a lot of questions, but more answers means more info for LG.net
And one more thing, the old fuorescents had a LP/W of about 35, the Beryllium tubes.

The equivalence thing is not a game. A 60w incandescent bulb gives out 800 lumens on average. So a led bulb that gives 800 lumens as well would have 60w equivalent on the label. Same thing CFLs have been doing for years.

People are familiar with 40w, 60w, 75w, 100w, and so on. So it makes sense to say this LED/CFL is equivalent to this bulb but uses less energy to produce a certain amount of lumens. Nothing to do with makers "getting caught" or some tinfoil hat BS like that.

Changing the "measure light amount by wattage" to "measure by lumens" in stores will confuse a lot of people. So if they ever do that they'll have to transition the lumens in and incandescent watts out slowly.

I'm talking about the ebay LED sellers with their Corn-On-The-COB LED bulbs.

Corn COB LED bulbs are known to be bad.
But the equivalence game is really for high power LED lights, the MH replacements, etc.
Then you get half the light for the same claimed output.

The stated Lm can be assumed to be correct for most decent lamps. The Las Vegas start when there are comparative figures to other light sources, published by the manufacturer or distributors. If the lamp is a retrofit lamp, those would be probably figures comparing it to the lamp it is intended to replace

The extent of fooling varies, but this example from yesterday is classic :

LED tube (Fluorescent retrofit) i found in the janitor's office at my college. This tube is intended as a substitute for 36W T8. Its non directional and is diffused, so its light distribution really is identical to the T8, and spectral differences aside, we can compare it Lm for Lm

 - LED tube : 18W 1700Lm

 - Fluorescent : 36W 2500Lm (Halophosphor 765, the cheapest) / 2850Lm (Halophosphor 640) / 3250Lm (All 800' Triphosphors)

No doubt you'll save half the electricity with this LED tube (or a bit more if FL using Magnetic ballast), but it is nowhere near equivalent to the FL. Its output falls short of the cheapest 36W FL available, and gets somewhat past HALF the light output of the more advanced type

There is another Battle Dimension when it comes to directional LED lamps or luminaires : The LED lamp is more directional than the lamp it is compared to, and it is assumed, that you dont need the light coming elsewhere from the reference lamp. So in another case, a similar 18W 1700Lm LED can be claimed as equivalent or even exceeding the light output of the FL, but that is when assuming that none of the upwards light from the FL is usefull (assume matt black reflector behind the lamp ?) - Assumptions that are never correct unless everything was really set up to put the reference lamp into disadvantage

Example of other LED lamp, that does not play any games at all : Few "Pilot Eco" E27, E14, G6.5 lamps in my collection. They state Watts, Lumens, Distribution shape, and NO equivalence claims. Thats the way to go



Surprise, some of the biggest and greatest lighting makers play the same stuff. For example Holophane and their Highmast HMA* and HMA-LED series. They claim LED lighting that can save some outstanding amount of Energy. Comparing the light output from those LED lanterns, with HPS equivalents from the same manufacturer, leads to discovery that there is no magic - The LED uses way less power, and puts out even further way less light



Finally, there is the output spectrum of the LED. For the same light levels on an area in Lux (so for lamps with identical distribution, same Lumens), LED light provides inferior visibility to discharge white light sources, and where it comes to outdoor, then even compared to things like HPS

This is result of where in the spectrum quite a bit of the power from the LED is concentrated : In 450nm Blue. It is not close to the sensitivity of our Rod cells so its contribution to visible light levels is not very high, but it does balance the otherwise Orange light from the Phosphor to make White. Discharge sources put out quite a bit in the Green, which our eyes see much better

And its before we count in eye strain effects resulting from the very same Blue



Measuring light in Lumens, Distribution angles, and surface areas is the proper way to rate and design any light installations

Watt equivalence sorta works if it is done fairly, but..

 - With Incandescent it can indeed work, as Incandescents of the same wattage are really very uniform

 - With Fluorescent and HID, the reference lamp varies, so when you name a wattage, you dont really name an exact Lm figure. For example, 36W Fluorescent can be between 2500 to 3200 Lm. 70W MH can be between 6600 to 8500Lm. To what 36W T8 or 70W MH you will compare ? If you try, atleast try to be somewhere within the range, not like the above example with the 18W tube..



There are very good reasons to not use ABSOLUTELY ANY grid powered device "new from the Chinese sellers" on Ebay. Not restricted to lamps. They blow up, burn connected other devices, burn down houses, do hair design to users, and so on

And no, they dont get caught with that either



5mm LEDs are not really made for high power density. That is, there is only so much heat you can conduct out of a 5mm package without the chip temperature going very high

From there, its up to your design :

 - If you make a big sized lamp or lantern with lots of LEDs relative to its wattage, then the power on each LED is small, the relative area of the heatsinking area that "belongs to this LED" is sufficient, and you can use whatever LEDs you want and make a decent thermal design

 - If you try to get max power on min area, you must use LEDs with the lowest possible thermal resistance from the chip to the heatsink connection. This rules out by far both 5mm and Superflux



RGB LEDs would definitely change the way the spectrum is composed, especially in the R/G part : Either Red and Green peaks similar to the Blue, or the wide hill from the Phosphor. It is indeed very likely that you can get better LEDs with the RGB approach. However :

 - The Red and Green LED components are not as efficient as the Blue, so your resulting LED probably will be less efficient than todays Blue+Phosphor LEDs. This would mean, losing the key claim that is now pushing LEDs everywhere : That they are so efficient. So you get a possibly better LED, but one that you can't push on the market as hard....

 - The Blue is still there, any plans ?



The old Fluorescents dont exist anymore (except in our collections) for many decades. Not only that, but many of the peeps responsible for maintenance of the lighting in places are too young to know them at all. Its not like, "5 years ago we had those Fluorescents". So no point in using them as a reference lamp



Corn LEDs are cheap to make so Ebay is full of them, but technologically nothing prevents making a decent corn for a change

Corn LEDs are cheap to make so Ebay is full of them, but technologically nothing prevents making a decent corn for a change

I hope that time comes.
I actually like the look of them, But not when they replace HID.

Have you installed any filament LED lights? It seems to be a promisingly efficient LED type.

I have, I have a total of 26 LED filament lamps in my house, 10 under my kitchen units, 9 in the living room, 5 on the kitchen ceiling, on in my hallway, and one at the top of the stairs!
the other 4 lights in the house are fluorescent.

I have, I have a total of 26 LED filament lamps in my house, 10 under my kitchen units, 9 in the living room, 5 on the kitchen ceiling, on in my hallway, and one at the top of the stairs!
the other 4 lights in the house are fluorescent.

That must have taken a lot of money to do!

Kind of, I did it over a few months, but their price has come down a bit in the UK to what they use to be, you can get the 7watts here now for £8, ($10.59 in US money).

Wow, that's cheap.
I also wonder about the silliness of the daylight filament lamps because it looks like a old styled incandescent trying to be a daylight color.