DIYbanter - View Single Post - Are name-brand low-energy fluorescent "Green" bulbs any brighter thanstore brand?

Don Klipstein

In ,
wrote:

Don Klipstein wrote:
In article , Dave Garland
wrote:
Doc wrote:

Just got a 4-pack of the Walmart "Great Value" version of these energy-
saver style fluorescent 23w bulbs which they claim are equivalent to a
100w incandescent bulb. Not even close. It's about like a 40w bulb.

Are the name brand bulbs of this type any better?

Well, they should be brighter than a 40W incandescent. Check the lumens
rating, that gives you a number to compare. A typical 100W incandescent
is around 1600-1700 lumens. Walmart doesn't seem to give the lumen
ratings on theirs but a Sylvania CF23EL is indeed rated for 1600 lumens.

It may take it a few minutes to reach full brightness.

But it seems like all the companies cheat on the "equivalent to" rating,
if they say "equivalent to 100W" I figure it should be a bit brighter
than a 60W.

My experience is that non-dollar-store CFLs marketed as equivalent to
100W significantly outperform 75W "standard" 750 hour incandescents rated
1190-1210 lumens.

- Don Klipstein )

Lumen output drops quite a bit throughout a CFL's life, whereas
filament lamp fall in output is much less. Consequently to get a real
equivalent one needs to start with higher lumen levels than the
equivalent filament lamp.

CFLs when aged to 3,000 operating hours have about 10% (maybe a bit
more) loss of light output compared to that at 100 hours (industry-
standard break-in period, immediately after which their light output
is "officially" determined).

So the 1600 lumen "100 watt equivalents" can fade to about 1400-1450
lumens at 3,000 hours, and fade a little more to maybe about 1300 lumens
if and when they get to 6,000-8,000 hours or so. Even that is still a
bit brighter than "standard" 75W incandescents.

If your home is one of those where the line voltage is on the high side,
then incandescents will have much-enhanced photometric performance. Light
output from a CFL may be merely roughly proportionate to line voltage,
while incandescents have light output typically proportionate to line
voltage to the 3.4 or so power.
So if you hit a 1190 lumen 75W 120V incandescent with 124V, then you get
about 1330 lumens from that incandescent. In homes with higher line
voltage, incandescents get a "disproportionate boost" in performance - if
you are not bothered by them not lasting as long as they should.

- Don Klipstein )