Are lumen cumulative?

[Tom7227]

I just put up a new fixture. The old one had a cfl that was equal to a 75 watt bulb. I put that in the new one along with 2 that are equal to 60 watt bulbs. It doesn't seem that much brighter. Did I waste my time and money?

Thanks for your info.

Tom

[JohnMickish]

Lumen and watts each measure different things. A Lumen is a measurement of light and a watt is a measurement of power (loosly amps times volts but there are other factors that can play a part) used. Now to answer your question, I don't know, but I do know that two 13w CFL will be brighter than one 18w CFL, as long as the color of the lamps is the same and the color of the globe/reflectors is the same.

With a new fixture it's hard to tell if you are really comparing apples to apples. Clear glass, frosted glass or white glass, plus if it's reflected off the ceiling or shining down all play a large part in how the light hits you.