LED versus T5 efficiency
 

I went to look up LED versus T5 efficiency. It turns out LED beats up older technology like T12 and T8 and takes its lunch money. That's comparing 120v powered LED to T8, not ballast powered T8 LED replacements (these things add together the inefficiency of a ballast plus the inefficiency of LED power supply running off ludicrous high voltage). Turns out stepping up 120v AC power to a few hundred volts to power a tube, then stepping it back down to low voltage DC to power an LED isn't that efficient.
That shouldn't really surprise anyone.

After reading around I found that LEDs don't really offer any efficiency gain over T5. For overall system efficiency LED comes in anywhere from 70 to 100 lumens per watt.
T5 is consistantly 96 to 111 lumens per watt depending on the tube length and ballast.
A big part of the problem is all the junk coming over from china. The LEDs have cheap inefficient power supplies and their lumen output number is what ever they decide to stamp on the box to move product. LED light fixtures should easily exceed T5 efficiency by a lot but no one wants to pay for the newest generation of super efficient white LEDs and high efficiency power supplies, so only cheap junk gets manufactured.

I became interested in the subject when I got ahold of a bunch of free industrial grade, wash down rated high output T5 fixtures. I just assumed that LED light fixtures were super high efficiency and that even the new generation of T5 were outdated and inefficient. Boy was I surprised to find recent data saying in a lot cases LED can be less efficient than T5.

Also any advance in tech that improves efficiency of a power supply for a LED, would also in theory be able improve efficiency of a florescent ballast too. So that playing field is pretty much even, any improvements would be on the LED tech it's self.

I converted my 4' kitchen fixture from T8's to LED's, with LED's I bought from a commercial lighting supplier. I removed the ballast, rewired the bulb holders on one end and simply removed the wiring on the other end. All was good. The energy consumption shown on the packaging says 18w per bulb. I also noticed the light output was better than the T8's I replaced. {I am not electrically inclined, but with a couple of YouTube videos under my belt, I was okay to convert the fixture.}

Then, I bought some LED's from Lowes to do my garage lights and found out when I got home that they required a functioning T8 ballast! I took them back. I checked Home Depot, Costco & Walmart and they were all the same way, needing a T8 ballast. It cost roughly double to buy the lights that didn't require a ballast than the Big Box store T8 ballasted LED's, but I figured it keeps me from wasting the ballast energy and from being mad when I'd need to replace a florescent light ballast to make my LED's work.

There are utilitec single pack T8 led replacements that are dual power capable for under $4 each.
Has to be the single pack, the utilitec dual pack are ballast only.
They can run off ballast power or straight off mains power.
I'm going to get a few tonight hopefully.

OP4, Did you get those lights?, and are you going to try and hook any up with the ballast removed?

I'm very interested in the outcome. I'd not even considered it possible to have an LED capable as an "either/or" powered replacement.

Yes I bought 10 of them.
These are hybrid tubes. Hybrid tubes can run off ballast or 120 to 277v power.
I found that the led T8 tubes use 26% more power when running on ballast power, compared to a mains power.
But even on ballast power the led uses 1/3 less power than regular T8 tubes.
But T8 tube versus led on mains power the leds use less than half the power of tubes.
My 6 tube fixture originally used 2.1 amps, with leds on mains power it dropped to 0.84 amps.

That is seriously good news to me. I didn't think of a way to test the efficiency, so I just hoped they were {at least close to} as good as they claim on the packaging.

I've replaced 16 T8 to unballasted LED's so far {house & attached garage} and have 12 more to change {never-ending barn project}.

It seems like the only florescent fixtures worth having are good quality high output tubes.

The high output T5 lights are industry standard, most HO T8 and HO T12 are not bad. The HO T8 tubes in my shed sucked, probably because they were warn out and/or possibly the incorrect tubes for the ballast. I have some HO T12 fixtures in my Porta store building on a count down switch (it's paid off or else I wouldn't be modifying it) and I do not plan on changing them because they are occasional use only.

I was going to put a HO T5 fixture in there but 210 watts of T5 was way too bright. 80 watts of HO T12 is just right.

A big part of the problem is all the junk coming over from china.

And an extreme lack of products available to buy that is not Chinese made in particular, or some other foreign country. :(

I have had to replace the ballast in some of my T5 high output fixtures, when I do I replace the single 4 lamp ballast with 2 separate 2 lamp ballast units, that way I can turn on 2 or 4 lamps.

So far out of 7 fixtures I have had to replace 14 tubes and 2 ballasts.

I just took a number samples of some of various size LED floods, they are rated from 60 to 70 lumens per volt-amp.
My brand new LED replacements are rated for only 75 lumens per volt-amp.
My regular T5 tube do about 107 lumens per volt-amp
My inefficient T5 high output tubes do 92 lumens per volt-amp, but these are supe bright and start at 0°F, since my T5 HO lights are out side or in building's that are unheated this is kind of important.
Either way, a lot more efficient than LED.
Why does everyone green wash all the LED tech and slam florescent?
Yeah old 1960s tech like T12 florescent suck.

Unlike LED you can actually get high quality T5 parts.
German made T5 tubes are the best by far but they are expensive, around $20 per 4 foot tube. Roughly double the price of Chinese tubes.
Most but not all ballasts are made in china, I have seen a few made in Mexico.

Probably because LEDs are easier to focus and easier to dim, making them more efficient in many "real world" applications. It is also worth noting that LEDs tend to be more efficient when dimmed.

That said, if you take a look at Linear Technology, you can find a lot of info about the engineering it takes to make fluorescent lighting efficient. Proper inverter design (good waveforms and all that) makes all the difference for the efficiency of a fluorescent lamp.

I don't want or care for dimable lights.
In the real world most lights aren't dimmed.

Plus these T5 fixtures are being used outside and in unheated buildings.

Moreover there are dimable T5 high output motion detection fixtures, where I work we have a few warehouses lit with these. They pop on at full power, dim down to stand T5 brightness, then turn off if they don't sense any motion after a few minutes.


If I want to "dim" my T5 fixtures I take the light fixtures that came with dead ballasts and rewire them with 2 ballasts.
So far I have only installed twin high output ballasts in my 4 tube fixtures and wired them to 2 switches. I could install a standard 2 tube ballast for 28 watt tubes and a high output 54w ballast in the same fixture if I wanted to.
2 high output ballasts give me 10,000 or 20,000 lumen settings, a standard and HO ballast would give me 6,000 , 10,000 or 16,000 lumen settings.
Plus the standard ballasts are cheaper than the high output ballasts, making it even more economical.

Edit: now that I think of it the HO plus standard ballast in the same fixture is a pretty good idea.

Ok so this discussion is focused on two ends of the spectrum and trying to directly compare them. Not fair.

Really to tell the truth, it's a lot easier to find a cheap LED light than a cheap t5 light. The t5 lamps were specifically developed to pack a wallop in a slim tube. Most of the non-HO lamps are specialty spectrum, like aquarium or grow lights or UV bulbs. It's possible to find t5 bulbs that aren't commercial grade, but you have to dig.

In contrast, the inexpensive LED lights are everywhere now. You can go to the dollar store and find them for a dollar. The HO, high efficiency variety are more on par with the t5 specs and price. When you get into the premium stuff, it runs neck and neck with the other high intensity, high efficiency technologies. In today's global economy, it's becoming more and more difficult to find products made economically in this continent. Due to the compact nature of LED emitter chips, it's much more sensible to mass produce them in Asia and ship them in bulk.

http://ecorenovator.org/forum/58508-post20.html

And that's how you end up with LEDs that are less efficient than T5 florescent.

And good luck finding single LED fixtures that give 12,000 to 20,000, or even 30,000 lumen. They are out there but they usually have their lumen rating overstated and they are expensive, and still less efficient than T5.

You will be pulling so much wiring, installing so many fixtures to make use of those cheap LEDs it will cost a fortune. And still be less efficient.

Compact LEDs are great for indoor residential lighting where you only need some light. Some where that you need a lot of light over a wide area, not so good.

My wife wants more light in the kitchen, I said alright I will put up one of my T5 fixtures. Because the 3 LED 100w replacements in the middle of the kitchen and 100w replacement cfl over the sink aren't cutting it. She didn't like that idea. I might still do it anyways.
We would be going from less than 4,000 lumen to 12,000 to 20,000 lumen depending on what I put in the fixture.
To get 12,000 lumen with cheap LEDs I would need to put up more than a dozen of them. That means adding boxes, pulling wires, installing fixtures. I would be surprised if I could do it for less than $15 per fixture my self plus it would be an all day project.

100W LED modules (that's an actual 100W, not 100W equivalent) are about $10 on Amazon. Get two of them, run them at 60% or so power, and you'll very easily get the level of light you're looking for. (For that matter, just one at 75% power will probably be enough or even too much - they really are insanely bright. Hard to describe unless you actually see one powered up in real life.)

I use "250w replacement LED floods" my favorite fixtures use 3 of these it lights up a half acre pretty good. Total they use 78w or about 90 volt-amps. But they are $33 each, but some of them the original 3 I bought are 5 years old now, I have 11 of them and plan to install more.
I have some LED light bars on my tractor and suburban, that use between 120 and 200 watts. They are pretty bright.
I had to use LED because my old tractors' alternator was only rated to make 20 amps.

Plus are these $10 100w leds even UL rated?
Burning down my house with cheap LED lights isn't going to save me any money.

https://smile.amazon.com/dp/B00CZ6QDDU/
I plan to use mine in a portable photographic/strobe light.

Mike,

I agree those 100 (actual) watt emitters are super high intensity! They are almost too bright for their size. I love the fact that there are so many enclosure and lens/diffuser options made to house them also.

Quick specs:
Model: 100W

Color: Warm White/Cool White

Forward Voltage (VF): DC 30-34V

Forward current (IF): 3000-3500MA

Out put Lumens: 8000-9000LM

Color Temperature: 6000-6500K(Cool White)/4500-5500K(Warm White)

Beam Angel: 140 degrees

Life span: >50,000 hours

So yes,oil pan is correct:A T5 lamp is brighter watt for watt with the right power source. Also, they don't need a heat sink. These SMD led emitters aren't a universal, generic part yet. But for a couple bucks apiece, they sure do fit in a lot of other fixtures with a little imagination.

Good 25W LED T5 bypass tubes now available.
 

I just installed 100 MaxLite 4 foot T5 bypass 25W tubes. (5000K) in our warehouse.
They are significantly brighter than the T5 HO that they are replacing. My i-sphere is too small to test them.

According to the GE ballast name plate the HOs were drawing 60W each wall power (Surprising I thought they were around 32-40W)
I'll run some tests when I get a chance to check actual watts, power factor etc. With the new (2018) utility incentive these tubes ended up costing us less than $1 each (plus my labor to install of course).
If nominal values are even close to correct, this should produce big savings.
The T5 direct wire (bypass) LED tubes did not become available until this year so ignore that you read about T5 replacement tubes prior to 2018.

re comment #19
Hi Jeff,

Most CoB LEDs I have tried have a fatal flaw. There are strings of LEDs in parallel without current regulation for the separate series strings. They try to match the forward voltage, but there are changes with aging. Also if the heatsink attachment isn't perfectly smooth there can be hot spots. Either way, over time some strings hog more current, have run away and the CoB fails. I've used a bunch and not had many of them last more than a few months, a year at best.
Let me know how these work out for you over the long term. If they are good then I'd like to know the brand. Meanwhile, I'm sticking with midpower LEDs, now up to 160 lpw.

Those T5 ballast must be old.
Mine are from 2013. They draw about 50 to 55 volt amps per tube on the high output ones.
I have some intermediate output ones, my Frankenstein fixtures that use a T8 ballast left over from my T8 LED upgrade, uses about 40va per tube, looks as bright as the full powered T5 tubes and these T8 ballasts are way brighter when powering T5 tubes than they were when powering T8 tubes they supposed to be used on.

Maybe late 2017 - 2018 will be the time that LED finally surpasses T5 in efficiency at the consumer level.
But will these LEDs be as relable as T5?
The LED should last something like 50,000 hours but not if it overheats. What about the power supply, if it over heats then it's finished then too.

My T5 LED tubes came in today. I have not tried them out yet.
ATM they are substantiallymore expensive than repowering a T5 fixture.
The cheapest I have seen them is $15 per tube that's if you buy a lot of them. If you only order a few you are looking at $17 to $23 per tube.
To re ballast a T5 costs between $7 and $12 per tube. The more tubes the ballast poweres, the lower the cost.
A 6 tube T5 ballast for a 6 tube fixture can lower the cost to as little as $5 per tube.

Back to the original T5-HO topic
I have completed my testing; here are the results from my Extech Power Analyzer. Not the most accurate, but good enough for relative comparison.

Ballast is GE 454MVPS90-E maybe a few years old but still reasonably efficient.
4 tubes tested in each case, in the same fixture
GE F54W-T5-850-ECO (also a few years old so not as bright as new ones)
233 Watts PF 0.984 (tubes presumably 54*4 = 216W, rest is ballast - ~8%)
Lunera HN-T5-D-48-25W-850-G2 (nominal 3500 lumens, older G1 is only 3200lm)
114 Watts PF 0.991 ( so about 14W used by this ballast assuming tubes are close to nominal 25W)
MaxLite L24T5SE450-CG (Bypass, line voltage direct into one end, easiest to rewire)
100.6 Watts PF 0.996 (ok, so 0.6W over nominal, probably measurement error)
nominal 25W 3400 lumens each

So these T5 LED tubes both provide more than 50% savings and are brighter than my (aged) fluorescents. I only bothered to replace ballasts where the ballast had gone bad in one or both sections. I was surprised at the small difference between bypass and direct replace. With older non-power factor correcting ballasts I would replace them.
Spreadsheet with details available on request - gavin.perry (at) MeridianLighting (dot) COM

I picked up some 2,800 lumen replacement LEDs and they don't appear to be putting off any where close to the light i get from my German made 54w tubes.
There appears to be a big difference in German made tubes versus chinese as they age.
My German tubes are not brand new, they are up to 3 years old.

2800 is a lot less than 3500 do I'm not surprised.
Recall I had GE ballasts and tubes. Who knows where they were made.

I have been playing around with the epistar chips and their DC driver boards for a while. The boards are built around the pt4115 chip. Before that it was the little Cree stars that look like a snowflake. I figured out the driver boards are dimmable, either by a shunt resistance or by pwm duty cycle. I also found out that a 10k NTC thermistor makes a good "don't burn up" dimmer while testing fixtures.

The other type I like is the 12v strip light tape. I dug up the specs for what I bought and shared it in another thread recently.

How much are these going to cost?

T5 HO are supposed to be up to 5,000 lumens.

I put one of these fixtures up in the foyer of our house. The wife says it's too bright and doesn't like the 4100 to 5000k light those particular tubes put off. I think I have some 3500k tubes.

The big difference between a t5 fluorescent light and a COB light is the profile. A t5 lamp is long and skinny where the COB lights are very compact. Most of the chips up to about 10w are roughly the size of a postage stamp. The 25w to 100w chips are maybe as big as a poker chip. They are more of a point source, like a halogen or arc discharge lamp.

All the chips I have been using are built on an aluminum substrate and have mounting holes drilled in them. They all need to be mounted to a heat sink using heat sink grease. The chips also have no current limiting or regulation mechanism built in, so if you do anything stupid with them they can quickly die. I have found that processor heat sinks from obsolete desktop computers work awesome. The fans that go on them run off 12 volts, too, and the nice fans have pwm speed control just like the drive boards for the chips. Highly tinkerable.

Yes I have used these before. I tried to make my own LED head lights with them years ago.

I was at Sams club and found some 80 lumen per volt-amp "60w replacements".
They're getting up there.

But at the same time I bought some 100w replacement leds from lowes that only do 50 lumens per volt-amps.
That's only marginally better than CFL, which does 30 to 35 lumen volt amp.

I put my kill a watt meter on one of my T5 fixtures, it runs about a .99 power factor.
These commercial/industrial power supplies are very efficient.
Commercial/Industrial users demand highest possible power factor and they get it.

In other news I found some very efficient LEDs, some 100w replacement's that are making 800 lumen for a total of 95 lumens per volt•amp.
But they're double the price of the cheaper 50 to 60 lumen per volt•amp bulbs but right about double the efficiency.
The much more efficient dimmable LEDs are about $10 each on clearance at lows, originally they were $13 each. The cheaper ones are 4 to 5 dollars.
From a $/lumen stand point this is pretty horrible.
But for indoors where you have a few fixtures and only need some light they are perfect.

I installed a T5 high output, high bay fixture in the foyer.
My wife was not too thrilled. It was a single function 4 tube fixture, with 5000k tubes. She said it was way too bright.
Turning that light on gave you an optical assault of 20,000 lumens.

So I took the single function T5 fixture out, installed a dual function with two T8 ballasts, took 14/3 wire hooked up to the fixture and hooked up an unused wire to be hot all the time, installed a pull switch so 2 tubes can come on from the wall switchs and the other 2 from the pull string by the bedroom door hanging from the ceiling box, running about 35w per tube and installed 3500k tubes. She says that's not as bad. It's probably running up to 7,000 to 8,000 lumens with 2 of the 4 tubes on.
Just using 2 or the 4 tubes is much brighter than turning all old the lights on. There 4 fixtures total in that foyer.