Cool light from very cheap energy saving bulbs

My local discount store sells energy saving bulbs at a very cheap
price.

I mean the type of lamp made up of small folded fluorescent tube
which plugs into a standard light socket. http://snipurl.com/nn87

There is no color temp written on the discount bulbs but I notice
their light is very noticably cooler than some similar GEC bulbs I
have. They are rated at 9 W, 11 W, 20 W.

Is the color temp of these lamps pure a matter of choice or are there
some technical, financial or marketing reasons which determine why
the lamps give off such a cool light?

 

I don't know, maybe cooler colors are cheaper to produce. I have
purchased $1 CFLs that produce a daylight color. One brand I bought was
good, the other brand failed anywhere between 2 minutes and 40 hours.

 

In warmer climates a cool white is preferred and in cool climates a warm
white is preferred. I think the biggest market for CFL's is for the
warmer climates so they use the cool white phosphors.

It's interesting that some of the cheap lamps have very good colour
rendering indexes. (CRI's) It would be nice to see a side by side
comparison with a "full spectrum" lamp.

Some attempts at warm white are woeful and give off a lurid fleshy
colour.

If you end up with any dead CFL's then remember that the little torroid
feedback transformer inside is ideal for making Joule Thief type
circuits that drive a white LED from a 1.5V cell. All you need to add
is a 1k resistor, a common NPN transistor and some fine enamelled wire.
Just thought I'd mention it.... You can find the Joule Thief on my
website below.

 

It's mostly a matter of choice, and has been said, there are
regional differences in color temperature preferences. Note
that at a given CCT, the color quality, CRI, is a matter of
economics.

--
Vic Roberts
http://www.RobertsResearchInc.com
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I have tested a lot of dollar store CFLs. Most are "daylight" color to
slightly more blue. The phosphor is usually the cheaper halophosphor
general type.
One thing I have found fairly consistently of $1 and $1.50 CFLs from
dollar stores: They produce less light than claimed, and generally by a
larger extent (sometimes by a factor of 3) when the claimed output is
higher.

- Don Klipstein ()

 

IMHO (and this is based on subjective evaluation with my eyes, not
measuring with instruments) *all* CFLs are less effective than the
equivalent incandescent wattages printed on the packaging.

I like CFLs anyway, because they save energy and last much longer. I
just replace 60W incandescent lamps with "100W equivalent" CFLs, for
example.

 

By "smaller by a factor of 3" do you mean 1/3 the claimed
output? Is this a measured value? I've seen low output
lamps but ever as low as 1/3 the claimed output - but then
again I don't do my lighting research in dollar stores

--
Vic Roberts
http://www.RobertsResearchInc.com
To reply via e-mail:
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site without written permission.

 

I agree that some of the "equivalent wattage" statements are
too high. You should be comparing the output in lumens for
the various lamp types. Even then, the subjective
evaluation of some people is that CFLs don't produce as much
light as an incandescent lamp with the same lumen output.
Other than differences in light distribution, I don't have a
good explanation for this. Perhaps Terry has additional
explanations.

Good!

--
Vic Roberts
http://www.RobertsResearchInc.com
To reply via e-mail:
replace xxx with vdr in the Reply to: address
or use e-mail address listed at the Web site.

This information is provided for educational purposes only.
It may not be used in any publication or posted on any Web
site without written permission.

 

It is my impression that this is a large factor in people
deciding not to use CFLs. An answer I've heard many times
when asked why not use a CFL is that they bought one with
the equivalent power to the existing filament lamp, and it
was far too dim. That became their first and last experience
with CFLs.

One factor may be the poor cool starting light output, and
without any realisation that the thing will get brighter in
a minute or so -- it might not even get a minute or so to prove
itself before it's been removed. Another factor I've heard
is that the light comparison can be with things like soft-
tone lamps which for the most part aren't what people use.

My rule of thumb is to multiply the power by no more than
4 times to get the equivalent filament power, and ignore
the filament power equivalent written on the box. For 120V
filament lamps (as opposed to 240V ones here), the factor
might want to be less than 4. The actual factors used on
the lamp cartons is always greater than 4 times -- usually
5 times.

 

I tend to replace a 100W lamp with 100W's worth of CFL's, and that
doesn't include the shit power factor, so I probably end up using more
power.

The new UK building regulations seem to be resulting in the installation
of pendant lampholders with an integral electronic ballast that can only
take the bare compact fluorescent lamps. Accordingly their price can be
anything the suppliers like.

Such a bad idea wiring an electronic ballast in directly to the
permanent wiring. Most householders will not be comfortable
disconnecting the dead ballast from the ceiling rose themselves.
(Assuming they're even allowed to with the part P nonsense.) Somebody's
going to be making lots of money.

 

Yep -- that's under Part L of building regs (conservation of energy
and power). A certain proportion of commonly used rooms in a house
must be lit with luminares with an efficiency of 40lm/W or better,
which must not be able to take lower efficiency lamps.

I don't object at all to encouraging use of more efficient
lighting. But as always, it's been gone about the wrong way.

Apparently, electricians often have a handful of these that they
lend out whilst the building inspector does the final check, and
then they recover for use in the next job.

The choice of available compact fluorescent luminares for the home
market that are even vaguely acceptable in the home is vanishingly
small. Pretty much all my home lighting is compact fluorescent (with
a mixture of self ballasted and remote ballasted lamps), but it is
nearly all made by me, as I can't find any aesthetically pleasing
luminares to use.

 

Yeah, but have you made one of my sputnik lights yet?

http://www.emanator.demon.co.uk/bigclive/hamster.htm

I'm lighting the room with it as I type. It's been tamed down though,
the top lamp holders are fitted with flicker flame neon lamps.

 

I don't have anything better than a Bunsen photometer and plenty of "Big
3" incandescents to compare against. And a few voltmeters and a "variac"
to supply exactly 120V to incandescents with. And I know how a quadtube
has different light distribution from "soft white" and close to but
slightly different from a bare CC-8 or CC-6 filament aligned in the same
direction. And that determining lumens this way gets "fudgier" when one
lamp has CCT below 3,000 K and the other has CCT in the 6500-8000K range!

But I have yet to see a $.99-$1.50 "dollar store CFL" impress me as
outshining the brightest 40 watt A19 lamps that come in packages claiming
505 lumens - none of 42 "models" of 16 "brands" that I tried! This
includes some that claim to replace 100 watt incandescents, a few claiming
to replace 125 watt incandescents, and a few claiming to replace 150 watt
incandescents. This includes two claiming to produce 1130 lumens and one
claiming to produce 1580 lumens! Most avoid lumen statements, even most
with claims of "incandescent equivalence" or "incandescent replacement" or
the like.

1580 or 1130 lumens from something that I see as slightly dimmer than a
40 watt A19? GRADE ZZZ-minus BULL COOKIES!!!

- Don Klipstein ()

 

This shows a very neat resin job on the bulb on the left.
http://www.emanator.demon.co.uk/bigclive/joule10.jpg