[geeks] Quiet CFLs

[Jochen Kunz]

On Mon, 1 Oct 2012 15:27:40 -0400
Nathan Raymond <nraymond at gmail.com> wrote:

> it's fairly easy and not
> that expensive to get high Color Rendering Index (CRI) halogen A19 bulbs
> that product accurate colors and aren't overly intense in the blue
> spectrum. 
The spectrum of incandescent lamps, such as halogen lamps, is
continious by principle, as they are black-body radiatiors. This
results in a high CRI.

> The CRI situation with LEDs seems much more complicated right
> now, and I would guess more expensive
> (I doubt there are $10 A19 LED bulbs with a high CRI...)
Yes. Most LED lamps have only modest or even miserable CRI. Especially
if they emit a cold white / blueish white light. If you want a high CRI
you have to look for LED lamps that are explicitly soled as high CRI.
But those are rare.

Also keep in mind that retrofit LED bulps, that replace incandescent
bulps, can't work well by principle. Incandescent bulps work better the
hotter they get. So incandescent lamps are designed to isolate heat and
keep the bulp hot. LEDs need the exact oposite. They need to be cooled
well to work well and reliable. This simply doesn't fit.

If you want good LED lightening you have to by new laps that are
designed as LED lamps from the ground up. It gets complicated and
expensive if you put in a high CRI as a requirement. Most likely it
will be better to build such a lamp by your own. Thats the route I am
on. I just ordered some neutral white high CRI chip on board LED modules
to build my own lamp for my living room.

If you wane build somthing your self have a look at the newer Bridelux
modules. The newer warm white versions often have a high CRI. Or look
at complete kits like the Cree LMH2. Includes the LED module, heat sink
and power supply. It gives you up to 3000 lumens at a CRI of 90 and is
mains powered. It's even dimmable.
-- 


\end{Jochen}

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