LED Lighting - Am I Missing Something?

[Brian]

As regulars will know I've a bit of an interest in LED based lighting products. One of my regular clients has asked me to look at low energy display lighting. As well as CFL I've been looking at LED but every time I do I come away thinking that I'm missing something.

 

Take the following spec for an MR16 LED unit...

# A 3W HIGH POWER LED SPOT LAMP, CHROME ALUMINIUM HOUSING, ACRYLIC LENSE " Equivalent to 25W Halogen Lamp "

# STANDARD MR16 5.3 FITTING, 12V, 200 LUMEN, " Direct replacement to halogen lamp "

 

Looks good..."equivalent to a 25W halogen lamp" and it quotes light output figures. But hold on; it claims to output 200 lumens which is fair enough. However, last time I looked, a small halogen would be outputting around 25 lumens per watt, so that's 25w x 25 = 625 lumens. Hmmm, so how can that LED unit which is outputting 200 lumens be equivalent?

 

Ok, so you also need to take into account optical efficiency but the MR16 is pretty good in that respect and I can't believe it would account for the LED being a factor of 3+ better.

[stillwave]

"equivalent to a 25W halogen lamp" and it quotes light output figures. But hold on; it claims to output 200 lumens which is fair enough. However, last time I looked, a small halogen would be outputting around 25 lumens per watt, so that's 25w x 25 = 625 lumens. Hmmm, so how can that LED unit which is outputting 200 lumens be equivalent?

 

IIRC it is to do with the way they benchmark the measurements, I too would doubt a 3W Led MR16 will be the equivalent of a 25W halogen... but if they put in the specs = 15W halogen would many people buy them? I wouldn't use them as general room lighting but accent lighting & display lighting they can be perfect. I'm LED mad, I even have one in the car as the festoon light (the one that comes on when doors open) but they don't work in all situations.

 

Regards

 

Ben Wainwright

[timsabre]

There's all sorts of dodgy claims about LED output made by (mostly far eastern) manufacturers. I guess there is not much checking up on these claims.

 

I've seen an MR16 made with a warm white cree MC-E LED (4 leds in one package=4W). It is similar to a 20W halogen, a bit dimmer probably, but the light quality is nice, you wouldn't know it was LED. Most of the LED "lamps" are really bluey.