Flourescent/strip light help if possible please.

[JohnW2]

No, of course not, those items have very limited working lives, ....

I'm rather amazed by the extent you are persisting - to the extent that I can't help wondering whether it is just a 'wind up'

In what way do you think that the life expectancy of a 'consumable' part of a product should alter my belief that to 'plug in a new light bulb or tube' is preferable to the owing the whole fitting away and getting a new one?

In any event...

(a)... I rather doubt that, for the average DIYer, the expected lifespan of, say, the blade in a table saw would be appreciably, if at all, less than that of, say, an incandescent light bulb - but people were very happy to replacing those bulbs, but would be very unlikely to be happy with a table saw that had to be thrown away and replaced when the blade became blunt.​

​

(b)... If you really believe that 'plugging in a new lamp/bulb/tube) is some sort of 'burden', leading you to favour throwing the fitting away and replacing it, wouldn't that 'burden' be even greater with something that had a "very short working life" (and hence had to be replaced very frequently)?​

 

[scooby1]

At only 64 lumens per watt, that is a pile of junk, significantly less efficient than the fluorescent it replaced, and a classic example of why some people believe that LED lighting is crap - because that one actually is.

If you can, suggest it's returned from wherever it came from. Even those cheap Toolstation ones are massively better.

Thank you as usual for your comments, sorry, but I didn't mean to upset you in any way, I had just got fed up of trying to make sense of all this "lighting business" it's not my area of knowledge. The light looked bright enough when I switched it on this afternoon and it would cost me money to take it back even if they would let me return it.
I did like the look of the second TS link that you sent me but I was out anyway today and just thought that rather than buy in the dark I wanted to actually pick something up and look at it which unfortunately you can't do in TS or SF.

 

[SUNRAY]

At only 64 lumens per watt, that is a pile of junk, significantly less efficient than the fluorescent it replaced, and a classic example of why some people believe that LED lighting is crap - because that one actually is.

If you can, suggest it's returned from wherever it came from. Even those cheap Toolstation ones are massively better.

Without personal knowledge of the item, I'm not in a position to offer an opinion based on product experience.
However if the numbers are correct, based solely on those I feel your description is an appropriate starting point and further I'm getting tempted to get one to be able to compare it with the items which you recommend to see just how much worse these things can get.

 

[SUNRAY]

... I wanted to actually pick something up and look at it which unfortunately you can't do in TS or SF.

Both flavours of my local branches will bring one to the counter to view if it's in stock.

 

[JohnW2]

..... if the numbers are correct, based solely on those I feel your description is an appropriate starting point and further I'm getting tempted to get one to be able to compare it with the items which you recommend to see just how much worse these things can get.

This reminds me of a question I've always wondered about....

If it is true that there is fairly wide variation in lumens/watt in these products, I wonder how that comes about. I don't know much about the manufacture or specifications of LED elements but, since the energy has to go somewhere, I can but presume that the ones with the less light output per watt must get hotter - and, from what is being implied, do I take it that the ones that get hotter are, for some reason, cheaper?

 

[flameport]

Generally for decent LED lighting you want at least 100 lumens/watt. Even the cheaper items from the likes of TS and Screwfix can achieve that now.
However caution is required particularly with no-name imported affairs as it's entirely possible that quoted specifications are just made up nonsense.

Fluorescent tubes were around 70-90 lumens/watt, although that decreases with age, and they take several minutes to reach that output.

There are also the considerations of colour temperature and colour rendering accuracy.

 

[JohnW2]

Generally for decent LED lighting you want at least 100 lumens/watt.

As I've just asked (by implication), can you help me understand how/why the apparent appreciable variation in (claimed, if not real) lumens/watt comes about?

However caution is required particularly with no-name imported affairs as it's entirely possible that quoted specifications are just made up nonsense.

What about the other way around? Is it possible that some of those claiming the higher lumens/watt figures are simply lying?

 

[SUNRAY]

... Is it possible that some of those claiming the higher lumens/watt figures are simply lying?

I'm convinced that is the case when I compare what are supposed to be comparable light sauces.

 

[JohnW2]

I'm convinced that is the case when I compare what are supposed to be comparable light sauces.

I do wonder! I probably should have added a bit (below in red) to what I recently posted, to clarify the point I was trying to make ....

What about the other way around? Is it possible that some of those claiming the higher lumens/watt figures are simply lying - and that those you describe as 'a pile of junk' because of their low claimed lumens/watt are the ones actually telling the truth ?

 

[flameport]

What about the other way around? Is it possible that some of those claiming the higher lumens/watt figures are simply lying?

Any information could be lies, but if the manufacturer provides a proper datasheet and other files with the specification, light output and other data then it would normally be valid.
Such as those available here: https://integral-led.com/en/product...lm-30w-130lmw-4000k-120-beam-1470mm--ILBTC113 for one of those Toolstation items. The LDT file containing all of the expected info.

Those that can't or won't provide information should be considered suspect.

 

[JohnW2]

Any information could be lies, but if the manufacturer provides a proper datasheet and other files with the specification, light output and other data then it would normally be valid.

Yes, it 'normally' would (be expected to be, but ..... !!

Those that can't or won't provide information should be considered suspect.

Maybe, but we're talking about a situation in which you deemed a product to be "a pile of junk" because of information (claimed lumens/watt output) which they can and did provide. Asked, is it possible that they are telling the truth and those those who claim much higher lumens/watt (so that you presumably don't regard their products as "piles of junk") arethe ones that are doing the lying?

You (or anyone else) haven't yet attempted to answer my technical question about how it comes about that there is seemingly a fairly wide range of lumens/watt figures for LED lamps/tubes (at least, in terms of manufacturer's claimed figures).

 

[flameport]

Maybe, but we're talking about a situation in which you deemed a product to be "a pile of junk" because of information (claimed lumens/watt output) which they can and did provide.

If that 64 lumens/watt figure were correct then it is indeed junk, as it would be worse than the fluorescent it was intended to replace.

Asked, is it possible that they are telling the truth and those those who claim much higher lumens/watt (so that you presumably don't regard their products as "piles of junk") arethe ones that are doing the lying?

As if often the case, you are asking questions which no one has the answers to.
While it's possible that manufacturers who provide lighting data could be lying, it's highly improbable.
More likely is that the data they provide is correct even if it does reveal the product to be junk, so it's an easy choice to determine what is suitable. Others who provide nothing are the ones to avoid completely.

how it comes about that there is seemingly a fairly wide range of lumens/watt figures for LED lamps/tubes

There are many different types of LEDs available, many different phosphors to use on them, various types of substrates to attach them to, different circuit configurations for them, numerous options for the type of driver used to power them, different types of enclosure/fitting to put them into and so on.

The main considerations for light output are how efficient the individual LED chips are, how well matched a batch of LEDs is, how good the phosphor coating is, and what drive current is used, and what that can be largely depends on how effective the cooling is, which is why battens typically use a large aluminium core PCB which extends for the full length of the fitting. Inadequate cooling and they won't last long, or they can be driven at lower current to last longer with a lot less light output per watt.
The better drivers are separate units in their own metal enclosure so the heat from the LEDs does not also heat up the driver. Others can be shoved on the same PCB as the LEDS so they all heat up and fail together.
Choices are endless.

 

[scooby1]

If that 64 lumens/watt figure were correct then it is indeed junk, as it would be worse than the fluorescent it was intended to replace.



As if often the case, you are asking questions which no one has the answers to.
While it's possible that manufacturers who provide lighting data could be lying, it's highly improbable.
More likely is that the data they provide is correct even if it does reveal the product to be junk, so it's an easy choice to determine what is suitable. Others who provide nothing are the ones to avoid completely.



There are many different types of LEDs available, many different phosphors to use on them, various types of substrates to attach them to, different circuit configurations for them, numerous options for the type of driver used to power them, different types of enclosure/fitting to put them into and so on.

The main considerations for light output are how efficient the individual LED chips are, how well matched a batch of LEDs is, how good the phosphor coating is, and what drive current is used, and what that can be largely depends on how effective the cooling is, which is why battens typically use a large aluminium core PCB which extends for the full length of the fitting. Inadequate cooling and they won't last long, or they can be driven at lower current to last longer with a lot less light output per watt.
The better drivers are separate units in their own metal enclosure so the heat from the LEDs does not also heat up the driver. Others can be shoved on the same PCB as the LEDS so they all heat up and fail together.
Choices are endless.

Thank you again for that detailed explanation, the majority of which I do not understand but that is my fault. It just seems so complicated when setting out to install a new light unit.

And for what it is worth I now have the light unit installed above the workbench in my machinery shed/workshop. I made some brackets which are fixed to the wall which enabled me to mount the light so that it is facing down as opposed to the original one which was mounted horizontally. But I am not impressed with the light or it's performance. As I wrote before, the structure is very poor in my opinion. The cable joint is terrible so much so that I had to re-wire it a couple of times when installing it on the brackets because the wires kept coming out of the connection. And I don't think it is very bright either. It will be interesting to see how bright it is in the Winter time when the workshop doors are closed unlike they are now with the bright sunny light and warmth being allowed in.

I think it is a case of you get what you pay for, or at least sometimes you do ! At least I have got my home-made mobile lamp as a backup, even if it's a bit expensive to run.

 

[JohnW2]

If that 64 lumens/watt figure were correct then it is indeed junk, as it would be worse than the fluorescent it was intended to replace.

Probably true - but, as you are always telling people, fluorescent tubes are obsolete, so a comparison with them in not really relevant.

If it were (hypothetically) the case that all LED tubes had appreciable 'worse' lumens/watt that 'the fluorescents they were intended to replace', we would have to simply accept and live with that, and I doubt that we would regard them as 'junk' simply because they had worse performance than something 'no longer available'.

As if often the case, you are asking questions which no one has the answers to.

That's what I suspected.

While it's possible that manufacturers who provide lighting data could be lying, it's highly improbable. More likely is that the data they provide is correct even if it does reveal the product to be junk, so it's an easy choice to determine what is suitable.

That's very probably true but, the great majority seem to provide at least some data, including a claimed light output.

Others who provide nothing are the ones to avoid completely.

I agree. However, as above, I think it's pretty rare to come across an LED lamp/bulb or tube which doesn't make claims, at least regarding light output (and usually also colour temperature and 'life expectancy').

There are many different types of LEDs available, many different phosphors to use on them, various types of substrates to attach them to, different circuit configurations for them, numerous options for the type of driver used to power them, different types of enclosure/fitting to put them into and so on.

Yes, I know all that - but I was asking whether anyone knew which of those factors were, in practice, the main reasons for the apparent fairly wide variation in (claimed) light output for a given power. What you go on to write about "the main considerations for light output" is not much short of a repetition of the entire list possible factors you mention above, so doesn't really help me all that much

As you presumably understand, the underlying question in my mind is whether the main factors which increase lumens/watt are (as many people seem to assume) necessarily ones that also increase manufacturing cost.

..... what drive current is used, and what that can be largely depends on how effective the cooling is, which is why battens typically use a large aluminium core PCB which extends for the full length of the fitting.

Are you perhaps implying that they use high, but pulsed, currents? If so, I wonder what the "lumens" figures they claim actually are? Provided the frequency of the pulses is high enough, 'persistence' of human vision will result in the perception of continuous light at roughly the peak level of the pulsed light, whereas an actual measurement of 'true average light output' (which may well be what we see in data sheets) presumably could possibly be considerably lower than that?

The better drivers are separate units in their own metal enclosure so the heat from the LEDs does not also heat up the driver. Others can be shoved on the same PCB as the LEDS so they all heat up and fail together.

That seems reasonable, but presumably will not have any effect on the lumens/watt,which is what we are discussing.