You are right that it's not just a case of getting an LED lamp. I got an 11W lamp from Aldi dimmable 806 lumen and 2700K which to me was a little too dim for the room works out at 73 lumen per watt. The one you link to is only 1W more but 1050 lumen so 87.5 lumen per watt, warm white is below 3000k so would be a little on reddish side likely same as one I bought. But also of course £3 v £6 not easy to decide if worth paying double for a little extra efficiency.these are really bright
http://www.toolstation.com/shop/p14618?table=no
Lumens are about 'brightness' and the colour temperature (e.g. 4000K) about colour. You could (within reason!) get any brightness (lumens) of 4000K lamp as you wanted - just as you could get an old-fashioned incandescent bulb in any size (hence brightness) from about 15W to 150W.As the LEDS seem to be measured in lumens now, what would 4000K be?
Indeed so - but I suppose that is an indictment of an imperfect "lumen meter". As I'm sure you know, luminous flux (measured in lumens) is meant to take into account the perceptive ability of the human eye.[/QUOTE]There was a trick done which made LED's look brighter. The LED was over driven then switched off and on so the watts remained the same but the amps increased as watts is time based and amps are not. Not sure if it was to make LED look brighter or by product from switch mode regulation the net result was it foxed the human eye but not the lumen meter. As a result one would look at a 1000 lumen fluorescent and a 700 lumen LED and the LED seemed brighter.
Yes it is meant to do that, but it still has to be measured by a machine. Also there seems to be more than one lumen those quoted for automotive lamps are measured after the lamp has been running for I think an hour but with other lamps there is no time limit. Also it can be measured per LED then multiply by number of LED's in the lamp or it can be measured for the whole lamp.luminous flux (measured in lumens) is meant to take into account the perceptive ability of the human eye.
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