[ale] More on LEDs...

[Ron Frazier (ALE)]

Hi Mike W and all,

It's cool to see that you have found the new LED's to be acceptable.  
These recent developments are very encouraging.  I think that, any time 
a CFL burns out, I may replace it with a LED, although I have a number 
of spare CFL's.  I don't know much about directional lighting though and 
don't think I have any.

Your comments prompted me to do some additional research.

In the previous discussion, I was encouraged to look at these things in 
terms of lumens rather than incandescent wattage equivalent.  This is 
very difficult, but obviously desirable.  One reason it's difficult is 
that I have no sense of how many lumens light an area, but I do have a 
sense of how many watts do so.  I guess this is just a matter of practice.

I dug up these articles:

http://en.wikipedia.org/wiki/LED_lamp
http://en.wikipedia.org/wiki/Fluorescent_lamp
http://en.wikipedia.org/wiki/Fluorescent_lamp_formats
http://en.wikipedia.org/wiki/Incandescent_light_bulb

These have lots of good info, although some of the info in one article 
is questioned.  In general, I think wikipedia is a good source.

The other reason that it's hard to think in lumens is that there is lots 
of marketing BS out there.

To help, I made the following from a chart in the incandescent lamp 
article.  This shows the lumen output of each type of each standard 
incandescent bulb.  I don't know where they got the data, but the 
numbers seem reasonable.  I've added a third column that computes the 
numbers for an acceptable 10% variance from the norm, when considering 
whether an LED light bulb is indeed equivalent to an incandescent bulb 
of X wattage.

Incandescent Bulb Output Chart

Power (W) ----- Output (lm) ----- Acceptable +/- 10%
5         -----   25        -----   23 -   28
15        -----  110        -----   99 -  121
25        -----  200        -----  180 -  220
40        -----  500        -----  450 -  550
60        -----  850        -----  765 -  935
75        ----- 1200        ----- 1080 - 1320
100       ----- 1700        ----- 1530 - 1870
150       ----- 2850        ----- 2565 - 3135

So, if I'm buying a bulb that claims to be 60 W equivalent, it should be 
between 765 and 935 lumens.  If it's outside this range, I'm going to 
avoid buying it and assume the manufacturer is trying to mislead the 
customer by making them think they're getting more light than they 
really will.  I saw some 40 W equivalent candelabra bulbs that output 
300 lumens.  I would not buy those as I consider the labeling misleading.

When I mentioned the possibility of replacing the 4' FL tubes we have, 
my wife said don't bother.  The fixtures are ugly.  Just replace the 
whole thing.  I guess she's got a point.  I think I'll defer that till 
later.  New 4 - 6 bulb fixtures and 4 - 6 LED's would probably cost me $ 
200 - $ 300.

I need to find a place to recycle 4' FL tubes and 8-9" circle FL tubes.

If the packaging on a bulb doesn't tell the color temperature (2700 K is 
soft white) and the lifespan in hours or something that's convertible to 
hours and doesn't say if it's dimmable, I'd probably avoid it.  As 
others mentioned previously in the other thread, you might also have to 
consider if they're rated for enclosed use and if they are orientation 
sensitive.

Hope this helps.

Sincerely,

Ron


On 8/11/2013 1:52 PM, Michael H. Warfield wrote:
> Hey we all had a lively discussion a while back about lighting class
> LEDs.  Just thought I would follow up and report my latest experience.
>
> Our kitchen was remodeled years ago with 4 recessed R40 can lights on a
> dimmer.  We've used dimmable CFLs in them since and have gone through a
> number of them.  So, yet another one burned out (they start to flicker
> badly before they completely die).  Ran out to Home Depot and bought
> another matching 20W (85W equiv 900 lumen) CFL but also bought a close
> equivalent Philips R40 14.5W 800 lumen LED.  I bought the CFL just in
> case the LED didn't match the other three lights closely enough for
> June's taste.  :-)
>
> Numbers...
>
> CFL: $12
> 900 lumens
> 20W
> 7.3 years life expectancy (based on 3 hours per day).
>
> LED: $35
> 800 lumens
> 14.5W
> 22 years life expectancy (based on 3 hours per day).
>
> Both bulbs 2700 degree color temp.
> Both bulbs dimmable.
>
> Oh, my...  Based on life expectancy (3 CFLs == 1 LED) they are almost
> identically priced with the LED slightly cheaper.  You've just got that
> upfront cost but, then, it's 1/3 the number of bulbs to change and buy
> at the store...
>
> Now...  Subjectively...  That 800 lumen bulb matches up to the 900 lumen
> CFLs in the other 3 cans almost perfectly (color temp and brightness).
> Again, subjectively, it actually looks to be slightly brighter and the
> face of the bulb is uniformly clean and white and looks more pleasing to
> me than the encased tubes of the CFLs.  The bulb is specifically
> designed for "down lighting" like these can lights (it's right on the
> packaging).  June is delighted with it.  I think I've bought my last
> CFL.
>
> So, to date, I've now replaced standard bulb shaped bulbs with LEDs and
> candelabra based bulbs in ceiling fans with LEDs and now dimmable CFLs
> in recessed can lights with LEDs.  The only thing left around this joint
> now are the full sized 4' fluorescent bulbs.
>
> In my book, LEDs have arrived.
>
> Regards,
> Mike
>    
>


-- 

(PS - If you email me and don't get a quick response, you might want to
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Ron Frazier
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