On 11/13/16 1:15 PM, dadiOH wrote:
"-MIKE-" wrote in message
news
On 11/12/16 12:42 PM, dadiOH wrote:
"Gramps' shop" wrote in message
...
Need to add some lighting. T8 or T12? Probably going with 2-tube
4 footers.

More - probably - than you'll ever need/want to know (downloads a
PDF, takes a while).
http://apps1.eere.energy.gov/buildin...offer_2013.pdf

To paraphrase it, if you want to save electricity, use LED; if you
want max light, use flourescent (use electronic ballast)



My actual experience would contradict that.
Lumens are lumens.

That's true. It is also true that T-8 replacement LEDs emit fewer lumens
than do T-8 fluorescents.


Not all LED tubes are equal, to the best of my knowledge.


However, the fluorescent lumens are coming from all areas of the round tube
while the T-8 replacement LED lumens are coming from maybe a 100 degree area
of the tube which means that the light falling on an object may be very
similar for both.


Interesting observation and again, not all are the same design.
However, on that tangent, I actually took the reflectors off mine
because I was getting more reflection from my white ceiling than the
fixture reflectors.


In reality, "lumens" is not a good way to measure the real life
effectiveness of illumination. For example, if one uses diffusers on their
fluorescents they are immediately losing 1/2 the light output from the
tubes.

In my shop, the fluorescent lights are recessed into a cavity between the
trusses. That cavity is painted white which reflects about 90 % of the
light hitting it which means that I am capturing some of the lost light ffom
the fluorescents that is going up/sideways (a more reflective surface could
capture more). If I were to replace them with LEDs, my shop would be less
bright.

My shop is brighter than daylight and I'm using less than 1/2 the energy
of fluorescent tubes.

How did you measure the brightness? Also, how bright and what is
"daylight"? Is it sunlight? A light cloudy sky? A dark cloudy sky?


With my eyes. :-)
I could see a lot better.
Everything was lighted up with not dark spots in the room.
Everyday, any time of day/night, any weather, all the time.

FWIW, in video production we considered daylight to be midday with
evenly overcast skies.


--

-MIKE-

"Playing is not something I do at night, it's my function in life"
--Elvin Jones (1927-2004)
--
http://mikedrums.com

---remove "DOT" ^^^^ to reply