Valid point regarding your concern about hype but let me relate this to my experiences.
Look at what happened with HD tvs.
We could get REALLY off-topic here, especially if I were to go into the fundamental differences in various HDTV display technologies (plasma, LCD, DLP, etc.), and why DLP was (and today remains, at least for the most part) only "pseudo-High-Def" at best. So let's get this at least somewhat back on track...
The govt mandated the end of incandescent lamps. This brought a lot of hype for both LED and those awful CFL bulbs. I for one am very glad that I didn't by into the hype of CFLs and all the huge issues that come with them.
CFLs have their place. But I agree that in many ways they are largely an "interim solution", forced into popularity by the premature and short-sighted forced abandonment of a well-established and high-functioning technology. In short: The EPA had absolutely no business (and
ZERO Constitutional justification for) effectively "outlawing" conventional incandescent light bulbs. But having done so, SOMETHING was needed to fill the void, and that "something" needed to be a more-or-less direct replacement for a standard light bulb, which could be directly screwed into the billions of existing lamps and fixtures which were already in the field.
I appreciate the effort you put in to show me cost differential but I clearly did not provide sufficient input as to why I think it is a 30-50% difference or about $500 to $1000 upgrade, and yes I was off.
I am in the planning phase of a garage addition. The garage is a working garage but not a painting garage. Here is a copy of the drawing and some sketchup captures that should help identify what I want to do.
Looks pretty nice. Is the "conventional" three-car garage to the left already in existence? Or is it too part of your expansion project?
Cutting to the chase, the software claims I can use 5 LED fixtures for the 8' area and an additional 21 for the 12' area. For 2 lamp fluorescent the program indicated 4 fixtures for the 8' area and an additional 18 for the 12' area. So 26 LED fixtures vs. 22 fluorescent fixtures so this is close to what you predicted.
However, we are still talking apples and oranges. The surface mount fluorescent have significant issues in the 8' area as they take away valuable head room. One possible solution would be to go with a troffer such as this one from lowes
I think you are grossly over-valuing that last two inches of headroom, particularly considering that it would only be "lost" in a few relatively small spots. But that too is your call to make.
Additional cost to upgrade to all LED is $2860 - $1100 = $1760 so yes, I was a bit optimistic.
So if I back up to the notion of using the LED in the 8' area only the numbers for that now look like:
4 x $50 = $200 for fluorescent
5 x $110 = $550 for LED
Additional cost to upgrade to LED in the 8' area only is $550 - $200 = $350
Will I hate mixing fluorescent and LED lights - hard to tell.
Since I will spend most of my time in the 8' area and I already know that I greatly appreciate the LED over fluorescent I know that most of the time I'll be very happy with the LED even if I have to turn off the fluorescent lamps in the 12' area.
In a sense, what all this boils down to is, "you want it because you want it." And sometimes, that's enough. Just don't kid yourself that there is any economic benefit to be had from it.
I could even spend a few $100 more and scatter some LED lamps among the fluorescent fixtures so that they can light that area at lower lumens when the fluorescent aren't on.
Until you actually try mixing the LED fixtures with fluorescent fixtures -- and very possibly experimenting with a variety of different tubes in the fluorescents to get the best "match" -- this is all pretty much throwing darts in the dark. That said, I strongly suspect that if you were to use a mixed-source approach, you will be happier if you keep them more-or-less segregated into separate areas, such as the "8-ft vs. 12-ft." scenario you suggested. In that way, you will be working under the influence of ONE type of lighting at least most of the time, depending on where in the overall space you are at that moment.
2ManyProjects said:
And let's not forget: The LEDs will continue to cost you more in operating costs, every day, forever.
I'm not convinced this is correct. The numbers seem to vary depending on the source but here is what I calculate from various numbers:
LED fixture: 3700 lumens / 43 watts = 86 lumens/watt
Fluorescent: 2700 lumens / 32 watts = 84 lumens/watt.
You can use other numbers to move this around but ultimately to me the lumens/watt seems to be a wash.
In the "broad strokes" context we have thus far been discussing this, that's probably "close enough". But the point is, despite the hype the LEDs are NOT significantly (if any) more efficient than a good fluorescent tube. Based on the values published on the Menard's web page you originally linked to (which is what I based my earlier comment on), they come out slightly behind a typical F32T8, and WELL behind an F54T5HO.
Now if I factor in that I can dim the LED and that I don't need to have 100 lumens in my face all the time than I think the equation changes. Assuming lumen/watt is relatively linear the operating cost of lighting should be less when I require less lumens.
First, the assumption that "lumen/watt is relatively linear" is probably not valid. While the situation MAY be somewhat better in this respect than with typical cheap incandescent dimmers, I would not expect it to be fundamentally different.
Second, you can
in effect achieve much the same "dimming" capability (albeit, with somewhat less flexibility) using fluorescent lighting,
IF you set it up correctly using a "multi-bank" switching scheme. And in THIS case, you actually do maintain that "linear" lumen/watt ratio, because those tubes/fixtures which remain unused in "low intensity mode" (for lack of a better name) consume ZERO energy.
The dimmer for the LED works through a controller that intelligently scales power consumption unlike incandescent dimmers that simply dump energy so dimming really should reduce energy consumption.
You are at least somewhat oversimplifying both of those technologies.
A conventional SCR-based dimmer for incandescent lights is actually fairly efficient, in terms of the power it puts into the lamp. It is the lamp itself which becomes less efficient when operated at less than its nominal maximum output.
Dimmer controls for LEDs can be implemented in several very different ways; but the BEST way (varying the duty cycle of the PWM signal which actually drives the LEDs) requires tight integration with (which typically translates to "built into") the LED fixture itself. "Outboard" dimmers designed to operate LED-based lamps which are themselves already "adapted" to 120VAC are considerably less efficient (and less flexible).
A tiny error in your comparison. Basically, reduce the Lumens for individual light sources by at least 30% when comparing them to complete LED fixtures. Better yet, use photometric data for complete fixtures.
How do you figure? If you mean to imply that 30% of the tubes' output is lost before it gets out of the fixture, that would depend almost completely on the specific fixture itself, and will vary greatly from fixture to fixture. Further, it strikes me that a 30% loss would be unusually high. For a typical open-tube "strip" fixture, even 5-10% would be a "generously conservative" estimate.
Also, the LED power requirements are for the complete fixture. You forgot to include the power losses from the florescent fixtures ballasts. Figure another 5 to 8 % loss. That puts the T8 fixture at about 56 lumens per Watt.
For sake of simplicity, I used the nominal values for the tube itself, since the actual power consumption (and the actual output levels) can be significantly impacted by the particular ballast used in any given fixture. Consider a ballast factor of 0.8 vs. one of 1.15, for example. Assuming a ISO-standard ballast with a 1.00 BF, the nominal tube values are pretty close; the 5-8% "ballast loss" you cited is probably a reasonable estimate -- but that's still nowhere near 30%
A quick calculation says about 40% increase in efficiency over a T8 fixture.
While I have little doubt that you could concoct a "stacked deck" sample comparison using a particularly efficient LED fixture vs. a particularly inefficient fluorescent, to imply that such efficiency gains are normal or typical is misleading at best.
