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How do lumens work--are they cumulative?

Posted by talley_sue_nyc (My Page) on
Mon, May 13, 13 at 20:22

My FIL made me a light fixture with 8 candelabra sockets (a friend of his who's a licensed electrician wired it for us).

He put 25-watt bulbs in it, each of them marked at 130 lumens. The package is labeled as "subtle, reassuring light."

The chart on the back says 1050-1999 lumens = "fresh, energizing light," but that's not what's going on here. Do the 130 lumens add up to 1,050?

Since there are 8 bulbs, I thought it might actually be TOO bright, but it's completely not. It's much dimmer than I like--maybe even dimmer than the 3-bulb fixture it replaced (though w/ 60-watt bulbs, it added up to 180 watts).

I'd have had him use normal-base bulbs, but he was nearly done before I knew what he was using, and I thought with 8 bulbs, it would be bright!

There are no shades; do you think I can switch to 40-watt bulbs? Do I need to do some sort of testing before I try it?

I'm not worried about it being too bright, aesthetically--I sew under that light fixutre, and I can't see well right now. I have a dimmer on that circuit that I can use the rest of the time. (I honestly think that reduces some of the brightness even when it's full on, because when the electrician put it in several years ago, substituting his brand for the one I'd pre-pursehd, the chandelier didn't seem to put out as much light.)


Follow-Up Postings:

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RE: How do lumens work--are they cumulative?

The short answer is yes. A fixture with lamps will be three times brighter than one with a single lamp.

Eight lamps at 130 lumens each would be roughly equivalent to a single 75w ordinary light bulb.


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RE: How do lumens work--are they cumulative?

wow, no wonder it seems dim! I was thinking maybe I was imagining things, but I don't think so. 75 watts is pretty dim for a 15x15 room.

Thanks for the help.


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RE: How do lumens work--are they cumulative?

Lumens from separate bulbs are not additive.10 100-lumen bulbs do not add up to 1000 lumens.


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RE: How do lumens work--are they cumulative?

Lumens are cumulative if they are shining on the same spot.

Getting them on the same spot is the problem without some type of aiming and focusing system.


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