A lot depends on hours of operation and ambient temperature.
A 96" HO tube has better terminations than a 48" standard, but usually
more than double the cost.
Life of either one is usually quoted at 20,000 hours.
If you are looking at a typical home workshop type application, consider
2-3 hours/night, 5 maybe 6 days a week will be about 20 hours per week.
20 hours per week, 50 weeks a year = 1,000 hours/year or 20 year life.
How long the system lasts becomes moot with numbers like that.
Things like inital cost, power costs, winter time temperatures, become
The very first one you want to address is temperature since light output
is so temperature dependant.
If you need insulation, that is ahead of lighting, IMHO.
Notice how everything I touch turns into a system<G>?
It's just the nature of the beast.
The shop will be fully insulated, heated, and cooled. Temps will be kept
at 45 to 50 degrees in the winter.
I definitely want T8 fixtures with electronic ballast. 4' or 8' is the
real question. The 8' fixtures are more than twice as much as 4' fixtures
from what I have found to date.
Double check price and availability of bulbs Brian. Not to say they're not
available, but which is more convenient, more common, cheaper, etc.?
One consideration I found worthwhile with the 4 foot fixtures is that I can
turn off fixtures I don't always need. Mine all have chain pulls on them.
For normal garage lighting I might get by on only half of my lights. Easy
to turn off the ones I don't want and still maintain the ease of hitting the
wall switch to light the bay to the normally needed amount of light.
BTW - did I tell ya that my freakin' garage is *bright* now?
I've gotten completely lost following the lumens, watts, 5's, 8's, rows,
and... man, my head is starting to hurt. But... I just changed the lighting
in my garage/body shop/woodshop from incandescent to florescent. I
originally had 3 100W bulbs in each of the three bays. The garage is 3 bays
(36x26) but only two bays are real car bays. The third is where I keep all
of my tools since it always seems to be too cluttered to actually use any of
them in that bay.
I bought the basic 0 degree 4 foot, double tube fixtures from Lowes - $20
each. I used standard 40W, soft white tubes in the fixtures . I put 6
fixtures in the two car bays. They run in two rows, from the garage doors
to the back wall, just inside of where the door tracks run. That puts them
roughly 8 feet (or a bit more) apart. End to end, each fixture is 32" from
its neighbor. I had to start about 52" from the front wall of the garage
due to clearance of the door as it opens/closes. I didn't care exactly what
distance the last light ended up being from the back wall. My ceiling is 9'
What I can tell you is that each bay is lit up like glory itself. It took a
little getting used to - the light is so different in color from the yellow
of incandescent. But in a short time it became quite natural seeming. The
best part - no shadows. I mean - no shadows. I don't care what you do, you
can't produce a shadow that obstructs your view. It was shocking to really
see everything that was cluttered on top of my table saw - and I'm not
I priced 8 foot fixtures and bulbs but all I could find locally - without a
lot of shopping around, was HO fixtures and the bulbs will take you to the
poor house. Not worth it in my opinion.
I wondered about color correction since I paint a lot of cars, but to be
honest, I'm not going to sweat it anymore. The light and the color are so
much better than what I was used to that I'll just stick with what I have.
My neighbors have made laughing comments about the light coming from my
garage now. I mean - it's a lot of light. My eyes are going the wrong way
fast and I just can't see like I used to in low light conditions anymore.
Not a problem anymore.
So - I don't know what the lumens are, don't care. Don't care what the
watts are. Don't care about 5's, 8's or 12's. I got light now and it was
quite reasonable the way I did it (price wise).
Hope this sheds some light on the discussion.
You get the message.
For your application, you could care less what the true color is, but
you sure care that it is repeatable, 24/7.
Have done some work on "color tables" as they are called.
Requires a controlled temperature, a specific set of lamps that have
been precalibrated, with known hours of operation, and a whole bunch of
People who need a color table are ink manufacturers, greeting card
IOW, the print portion of the graphic arts industry.
Doing a color table is strictly for the prestige.
Lots of time for small amounts of money.
On Sat, 26 Nov 2005 20:51:20 +0000, Lew Hodgett wrote:
Don't know where you came up with that number, but it sounds golden and
looks to solve my own lighting questions. I'm in a basement with a 7'
ceiling so I should be fine with anywhere from 1/2 w / sq ft (~50 fc?)to
the full watt (slightly greater than 100 fc).
On Sun, 27 Nov 2005 19:56:14 +0000, Lew Hodgett wrote:
I took a closer look, got measurements and dirtied a piece of graph paper.
I have 372 sq ft on a 12 x 31 rectangle. That argues for 10 x 40w tubes.
After considering the effect of 80x (2x40w) directly over my lathe, I
don't think that 400w is going to cut it. I decided to put a row of single
tubes 2' away from each wall and end with a row down the middle
(lengthwise) offset by 2' to balance things out. The rows
are designed to be no more than 48" apart, although a couple of
obstructions (plumbing) will cause this to vary somewhat. This will yield
15 tubes for a total of 600w general lighting. There will be additional
point-of-use task lighting at the bandsaw, lathe and drill press.
Possibly also at the table saw over the router table wing.
All lamps are "daylight" spectrum, 6500k, 2325 lumens.
I'm tired of squinting in the dungeon.
It's not rocket science.
Play with several layouts before you commit.
Don't forget you can use supplemental task lamps for specific tasks.
Uniformity of the lighting is the controlling fsctor.
I started to scan about ten pages from the illuminating engineering
handbook, but realized no one does them by hand anymore. Its either
rule of thumb, or we use software. Most distributers, have access to
design software. I just ran it out real quick on one program 15
2/lamp 4' T8 fixtures for 80' candles, and 20 will get you a little
over 100 FC. That assumes 70% ceiling, 60% wall and 20% floor
reflectance. Also these are maintained FC, initial light levels
will be higher. 2.5' work plane. 3 rows of 5 8' between columns and
5' between rows. Assume this is the center point of fixture. If I
have time I'll run it on my best program and turn it out as a cad
drawing and copy it to abp group. Newest program even does visual
renderings of the interior space.
On Sat, 26 Nov 2005 13:26:37 -0600, Ricky Robbins
That is known as the LGB theory of lighting design.
You bring in the out of town lighting guru from the factory.
Take guru to job site for an inspection.
Guru looks around and says, "Put luminaires here, here and here",
pointing towards ceiling.
"Now, Lets Get a Beer."
Thats how I ended up with my own software, I'd send a parking lot to
be redone in showing the existing pole locations and they would do a
new lay out. I'd end up with poles in the roadways. LOL On the
interior jobs they never considered the beam and obstacle locations.
In the end you still have to sit down and use your common sense. I
usually look a lot more at the uniformity then the actuall FC and try
to consider the Visual comfort on low ceilings. What I threw out
earlier was just a quick estimator program.
On Sat, 26 Nov 2005 22:09:54 GMT, Lew Hodgett
Ye gads, unless it was a car lot, 4:1 pole spacing ruled for parking
lots as long as the poles were 40 ft or less.
Roadway jobs, now that is a whole nother kettle of fish which I avoided
like it was the plague.
Times have sure changed I guess.
In reefkeeping, T5's are the new black. They allow for more light with
a smaller fixture, the bulbs last quite a bit longer than T-8's, are
cheaper to operate than MH, and put out more light than a compact
That said, the light available is more a product of the reflector
chosen than the bulb. The t-5 allows a smaller reflector that bounces
more light down into the tank.
I have T-5's over my tank and track lighting in my shop. It allows me
to put light exactly where I need it with no shadows (and I got 15
fixtures on Ebay for 10.00 so the price was right)
> The 8' ceiling is the controlling factor in the above application.
could impose on your previous life one more time...
If a guy had 29 x 51 shed with 12' ceilings (white steel panels on
ceiling and walls, insulated) hoping for 80-100 FC maintained.
How many would you recommend ? and what layout ?
(my flavor would be leaning towards 2 fluorescent 40 watt
lamps/fixture mounted to the ceiling) but if you have a better idea
for 12' ceilings, please let me know what you would do.
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