LED v CFU light outputs

[ericmark]

I tried LED GU10 some years ago and the results were disappointing so went to cold cathode however over the years this has faded and gone yellow so was replaced with a standard quartz unit.

Then my wife went to Pound World and came back with some GU10 and MR16 0.58W spot lights which on seeing wattage I laughed at. However stuck them in and was surprised how bright. Using as bedside lights they were good enough to read by.

In the bathroom 4 x 50W MR16 were replaced and the results were a rather dim room as one would expect but good enough and since a rather old system using a transformer not an inverter no real problem.

Next was a visit to Lidi and I got two candle type E14 bulbs to use in desk lamp next to key board. Finding one of the 8W globe type bulbs had blown I used one instead in main living room light and was rather surprised at the output. It seemed brighter than the 8W CFU that it replaced but only 1.4W. I aimed camera at the bulbs and 1/30 second F3.5 ISO 140 was shown with both lamps 8W CFU and 1.4W LED and the LED does not have a soft start. I did wait 1/2 hour before measuring.

This was rather a surprise I had considered LED and CFU to be on par so question are my CFU all faulty or are LED lamps better?

I compared at my desk the folded 11W florescent and the 1.4W LED and as expected the 11W is giving far more light out. If I had just one bulb in living room I would have blamed the bulb but 10 in living room and 8 in dinning room the dinning room is a different make and slightly brighter bulbs but this does to me raise the question in general are LED lamps better than CFU?

I also did the CD test tilting it to see the colour spectrum and the CFU gives three well defined colours where the LED there is a gradual blend between each colour likely better for my photography.

I did after look on internet and I do see claims that LED lamps are near half the wattage to CFU to give same light output.

 

[bhm1712]

wattage is not the measure of light output. The CFL (not sure where your getting CFU from) lamps may be higher powered in terms of wattage, but the lumen rating may be lower than the LED counterparts of a lower wattage.

For example, i have just bought some 15 watt CFL's with a lumen rating of 700 lumen. At the same time i bought one single 10 watt LED globe with a lumen rating of 830 Lumens. The colour temperature of the light from the CFL is also very different from that of the LED, which makes the LED look at least double the brightness.

 

[ericmark]

Sorry thinking compact florescent unit where seems called compact florescent lamp I was always as an apprentice told the lamp referred to whole thing back to days where we would place the oil lamp on a spigot on the wall. The compact is not bulb or tube shaped so calling bulb or tubes also seems wrong. Luminaire I would think like lamp refers to whole thing. Can't think of a genetic name for wick, mantel, bulb, or tube which could refer to the light emitting part of a lamp!

As to original question my mind tells me power goes in, nothing is lost so power comes out in different forms be it visual light or heat nothing is lost. So if both florescent and LED are cold then one would expect the same amount of light. Just touched the florescent at my desk top and LED and the florescent is warmer than the LED. Is this really enough to give such a marked difference in visual light output per watt? Or is power converted to some form we can neither see or feel?

I do remember looking at florescent tube light output and noting a marked difference both with tube coatings and induction control gear compared with inverter (HF) control gear I have never tried to measure the frequency of a CFL to see if HF or induction controlled and I wonder if using some thing like the HF 2D lamp would also give far more output per watt used?

At 6 or 8 watt to get same light output I would not have considered it really mattered but once it reaches double figures then maybe worth changing.

I will watch comments with interest.

 

[bhm1712]

As to original question my mind tells me power goes in, nothing is lost so power comes out in different forms be it visual light or heat nothing is lost. So if both florescent and LED are cold then one would expect the same amount of light. Just touched the florescent at my desk top and LED and the florescent is warmer than the LED. Is this really enough to give such a marked difference in visual light output per watt? Or is power converted to some form we can neither see or feel?

Its not as simple as that, no matter what power goes in, whether the different lamps are warm or cold, the light output will never be the same across different types of lighting technology just because they are the same wattage.

Consider a car engine, you may have 2 different cars, both with 1.8 petrol engines. Both engines may consume 1 gallon per 40 miles, and yet one may be 110 horse power, and the other 150 horsepower. Whether the engine is cold or warm, the output will still be different.

CFL technology is not as efficient as LED technology and thats what it boils down to. Its how the lamp circuitry and illuminating device actually transform the input power into output power. Dont forget that the light output from various devices is not always visible to human eyes. UV light is emitted from CFL's and not LED's. The more heat created also means less light output. Right from the moment you turn on the lamp, it will be emitting that amount of heat but you will not feel it straight away as it takes time for the surrounding materials to warm up to the point of being able to feel it.

On a seperate note, as an apprentice i was always scolded for calling light bulbs - bulbs. I was always taught that light bulbs are actually called lamps and the lamp fitting is the unit the lamp fits into.

 

[ericmark]

I had expected as I said that different coating will convert the UV light to visual light with slightly different efficiency but rather surprised how much difference.

As to lamp v bulb I was taught that a lamp was the total unit which was supported by when I ordered a head lamp I got the whole unit minus the bulb. Bulb clearly refers to shape. I was told by some of the fellow students bulbs grow in the ground and returning to work I was told that both light bulbs and growing bulbs were a bulbous shape but it is the shape refereed to.

The old guy said how words could be traced back into history and that be it oil, gas, or electric a lamp referred to the whole unit and on thinking about it this made sense. Inside the unit are the component parts. Glass or globe which would surround the wick, mantel, or bulb again as he said it all makes sense. The whole unit in days gone by would be lit on the table then transferred to a shelf of spigot. Even with the old carbide head lamp it would be filled and lit and the water feed adjusted then the whole lamp would be placed on the spigot at the front of the car. Same as with the old steam trains.

Having made a mistake once or twice and asked for or ordered a lamps instead of a bulb and got a lamp minus the bulb as in auto trade same lamp could need a 12 or 24 volt bulb I got into the habit of calling a spade a spade not a shovel and a bulb a bulb not a lamp. When we still had bulbs even the 230v versions were called bulb on the packet. And the BS7671 says we should follow manufacturers so should clearly be called a bulb.

We also of course had tubes. But just like we refer to CLI as being DOS even if not really the Device operating system we called the tubes festoon bulbs which I suppose was not really the right name but that's what they were referred to as. In the same way as I now realise that the folded or coiled florescent tube is called a CFL even if not really a lamp.

However I can't really think of a word which describes the user replaceable part in a lamp. Maybe a transducer but that is really only when used for measurement so an optical isolator would be a transducer but in spite of it containing an LED an LED is not really a transducer. So we have tungsten, florescent and LED but does not really matter if folded or coiled it's called a CFL. So what is compact? Is a circular florescent compact? Is a 2D lamp compact. Like the term down lighter which could be one foot square with a 2D lamp, a CFL or a 50mm spot lamp all seem to be called down lighters when sunken into the ceiling. The chandler also sends light down but not called a down lighter. Aircraft ground lights (AGL) clearly only shine up but we don't call them up-lighters. English is an odd language!

 

[bhm1712]

A compact fluorescent lamp or CFL normally refers to a lamp which also contains the electronic ballast and starting equipment in a single unit. A Fluorescent tube or 2D type lamp does not include this and so would not be called a CFL.

By definition, a lamp is ''a replaceable component that produces light''

Also by definition, a light fitting or fixture is ''a luminaire, often colloquially known as a lamp''

And on the same vane, an Oil lamp or Gas lamp is cited as being the original use of the term lamp.

 

[ericmark]

OK I see a "Luminaire" includes the ceiling rose a lamp is the bit that dangles from the ceiling rose. i.e. All bits that dangle from plug shown

which is what I said a lamp was.

I do some times wonder about the IET with their descriptions and definitions I was taught a radial was where the cable was protected at source and a spur where cable protected at destination but now even when protected at source with a FCU still called a spur.

Also final ring circuit is not a "final" circuit when spurs are fitted as a circuit is all that is protected against overcurrent by the same protective device and since there is another circuit after the 32A MCB supplying the ring it's not the "final" circuit.

Seems they have a problem with English!

 

[bhm1712]

lamps:

http://uk.rs-online.com/web/c/?sra=oss&r=t&searchTerm=lamps

Luminaires/fittings:

http://uk.rs-online.com/web/c/?searchTerm=luminaires&sra=oss&r=t

Light Pendant:

http://uk.rs-online.com/web/c/?searchTerm=lamp+pendant&sra=oss&r=t

 

[ericmark]

Oxford Dictionary

Definition of lamp
noun

a device for giving light, either one consisting of an electric bulb together with its holder and shade or cover, or one burning gas or oil and consisting of a wick or mantle and a glass shade:a table lamp
an electrical device producing ultraviolet, infrared, or other radiation, used for therapeutic purposes.
literary a source of spiritual or intellectual inspiration: he set out to rescue the lamp of American literature from the cave of the Philistines

verb

1 [with object] supply with lamps; illuminate:inspectors can lamp the lines between the manholes for routine maintenance observations
[no object] literary shine:an evil fire out of their eyes came lamping

2 [no object] (often as noun lamping) hunt at night using lamps, especially for rabbits: my best dog was in his prime and I was lamping every chance I got

Note:- consisting of an electric bulb together with its holder and shade or cover i.e. whole thing is a lamp.

 

[bhm1712]

Yes agreed but that definition goes back to the colloquial meaning. In electrical there is simply no piece of hardware called an electric bulb. It's a lamp. A lamp goes in a lamp holder and a lamp holder forms part of a light fitting or fixture or alternately a luminaire.

All this is really irrelevant anyway because either way we can all understand both terms and get by when it comes to buying lamps/bulbs/CFL's/tubes/Florries and so on!

Variety is the spice of life or so I am told!!!

The debate could continue for ever and a day just as the one about plug tops regularly does do!

 

[ericmark]

I would have to in some ways agree I have as I am sure you will have noted in other posts used the word lamp to refer to the bulb.

However as I read your reply I reached down and picked up a packet marked 60W pearl light bulb bayonet cap 220 - 240V.

My gripe really is how does one explain what one wants when words keep changing meaning.

As an apprentice had some one talked about a "Luminaire" he would have been told to speak English. We were not into Latin but it seems we are adopting more and more words.

In college I was taught about poundel, pound, and slug but away from college we only used the pound. But when we went metric we got the Newton which was metric equivalent of the Slug. OK understand the idea of gravity free measurement but the pound was good enough for years. Going to kilo OK but what's at this with Newtons. 32 lbs/sq inch in my tires was easy this Newtons per sq mm is a real pain. We have even lost the cm not allowed with ISO yet still taught in schools.

What an odd world!