# Lumiversal T5 retrofit for normal T8 or T12 fixtures...



## Electric_Light (Apr 6, 2010)

I found this thing online, then I also found this company spamming on other sites. 

To condense pages of their marketing sham, the retrofit kit is basically a daughter-board that hangs from existing fixture shell. 

The daughter-board has its own reflector and an integral ballast with 0.95BF. It fits into modified exiting medium bi-pin socket and a T5 normal output lamp is installed into the adapter. 

The fixture itself must be rewired so that one end is neutral and the other end is hot with a fuse box in middle. 

Instruction: 





Brochure: (ignore their marketing blah blah since its full of wrong) 
http://lumiversal.com/upload/LUM_LCM_Brochures_0310.pdf

Latest T5 lamps are more efficient than the crappiest T8/T12, but it's on par with the latest T8 and T12. They're certainly more expensive than latest T8 lamps. T8 lamps have a longer life under same conditions and they're equally efficient. Normal T5 lamps are basically built on the same technology so there's really nothing special. The F54T5/HO works better in extreme temperature only because they use amalgam instead of pure mercury. 

I have no idea what this gimmick costs, but I don't think they're cheap. 

They play the middleman for T5 lamps to be used in their fixtures, clerical work(do your incentives paperwork) and 
provide financing service... :001_huh:

I think its mostly a marketing gimmick. The fixture modification is more work than a normal ballast change out. If you've an old magnetic T12 system, then you should just change out to NEMA Premium T8 ballasts that meet the rebate requirements and high efficacy lamps (3100lm 32W). 

If you've already got a T8 electronic ballast system,then you can just CLEAN the fixture in addition to changing the lamps to premium efficacy 25, 28 or 30W lamps. The 30W provides the same output. The 25 & 28W lamps reduces output and power use if the current system provides more light than necessary.


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## FutureLED (May 15, 2010)

Electric_Light said:


> Latest T5 lamps are no more efficient than crappiest T8 and T12 you can get your hands on and they're certainly more expensive than latest T8 lamps. T8 lamps have a longer life under same conditions and they're equally efficient. Normal T5 lamps are basically built on the same technology so there's really nothing special. The F54T5/HO works better in extreme temperature only because they use amalgam instead of pure mercury.


Hmmm.... I can't comment on the company or its product, but I do have intimate knowledge of fluorescent technology and the advances that have been made over the past several decades. Your comment of "Latest T5 lamps are no more efficient than crappiest T8 and T12" is patently false. For somebody that appears to be well educated on fluorescent lighting I am curious if you simply don't know T5 technology and didn't bother to do any research before posting or whether you have an agenda to purposely misinform in an effort to disparage T5 and the product that this company sells.

Lets get to the obvious, a simple search of GE, Sylvania-OSRAM, and Philips bulbs will reveal the following, I settled on comparing at 4100K:

Latest in T5 lamps:

GE F28WT5/841HL/ECO 71654 - 3050lm (108 lumens per watt)
GE F28T5/841/WM/ECO 71644 (26W) - 2900lm (112 lm/w)
Sylvania FP28/841/PM/ECO 20944 - 3050lm (108 lm/w)

"Crappiest" T5:

Sylvania FP28/841/ECO/SL 21045 - 2813lm (100 lm/w)

"Best" T12:

GE F34SPX41/RS/WM/ECO 23159, 2900lm (85 lm/w)

"Crappiest" T12:

Sylvania F40CWP/UPC/1/30 24611, 2200lm (55 lm/w)

"Best" T8:

Maxlite F32T8/841XL 51050 - 3200lm (100 lm/w)

"Crappiest" T8:

Sylvania F32T8/741/ECONOMY/ECO 21618, 2700lm (84 lm/w)

This factual data shows that the best T5 bulb is over double the efficacy of the "crappiest" T12. The best T5 bulb is more than 10% more efficient than the best T8 bulb. Your comments are in complete contradiction of this.

Your comment of "Normal T5 lamps are basically built on the same technology so there's really nothing special" when comparing to T8 is equal to saying the same between T8 and T12, but clearly T8 has left T12 in the dust. In fact, the worst T8 I could find had the same efficacy as the best T12 I could find. This is quite coincidental as the worst T5 I could find had the same efficacy as the best T8 I could find. Regardless of T5, T8, and T12 being of similar technology there clearly is a difference between them that is something special.


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## FutureLED (May 15, 2010)

Electric_Light said:


> *Latest T5 lamps are more efficient than the crappiest T8/T12, but it's on par with the latest T8 and T12.*
> 
> ...
> 
> I think its mostly a marketing gimmick. The fixture modification is more work than a normal ballast change out.


Interesting how you edited your original post to make your statement less incorrect. Even with the correction it is still wrong, how do you figure the latest T5 lamps are on par with the latest T8 and T12?

I had a chance to watch the video you posted, for some reason it didn't show up when I posted my original response. Why do you say that the modification is "more work" than a ballast change out? It looks identical to a ballast change out.


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## Electric_Light (Apr 6, 2010)

FutureLED said:


> Hmmm.... I can't comment on the company or its product, but I do have intimate knowledge of fluorescent technology and the advances that have been made over the past several decades. Your comment of "Latest T5 lamps are no more efficient than crappiest T8 and T12" is patently false. For somebody that appears to be well educated on fluorescent lighting I am curious if you simply don't know T5 technology and didn't bother to do any research before posting or whether you have an agenda to purposely misinform in an effort to disparage T5 and the product that this company sells.


It was my mistake in posting. I fixed it. Case closed. I meant to say that T5 is nothing special and that its better than the worst T8/T12, but no better/worse than cutting edge T8/T12. Marketing literature for T5s tend to make comparison against the worst T8s out there to make T5s look better. 



> Lets get to the obvious, a simple search of GE, Sylvania-OSRAM, and Philips bulbs will reveal the following, I settled on comparing at 4100K:
> 
> Latest in T5 lamps:
> 
> ...


Just a few things. The WM, or the krypton filled energy savers run lower watts per feet, so the efficacy tend to be higher. 

T5 is a new comer and the specs are based on operation on ANSI high frequency reference ballast. Even though T8s are predominantly operated on electronic ballasts these days, both T8s and T12s specs are based on ANSI line frequency reference ballast. 

It's a well documented characteristic that lamps gain 10% efficacy at high frequency compared to 50/60 Hz, so this is what explains higher efficacy of T5s in catalog specs. 



> "Best" T12:
> 
> GE F34SPX41/RS/WM/ECO 23159, 2900lm (85 lm/w)


85lm/W @ line frequency. You can apply the generally accepted 10% gain in efficacy when operated on electronic ballast and give it an efficacy of 93.5lm/W 



> This factual data shows that the best T5 bulb is over double the efficacy of the "crappiest" T12.


That was my error in posting.



> The best T5 bulb is more than 10% more efficient than the best T8 bulb. Your comments are in complete contradiction of this.


This, I disagree, because of what I discussed about high frequency vs line frequency reference ballast for testing the lamp specs. 

Comparing the best T8 against best T5, there's little difference. The life is longer on T8(You will need to dig through data for programmed start, because the big advertised life for T8 assumes instant start while T5 assumes programmed start). Again, I made an error in post. Sorry for the confusion.


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## Electric_Light (Apr 6, 2010)

merge w/ below


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## Electric_Light (Apr 6, 2010)

FutureLED said:


> Interesting how you edited your original post to make your statement less incorrect. Even with the correction it is still wrong, how do you figure the latest T5 lamps are on par with the latest T8 and T12?


I fix my errors when I spot them. As I said, I made an error. 

http://genet.gelighting.com/LightProducts/Dispatcher?REQUEST=BALLASTSYSSPECPAGE&Lamp=F32T8&NoOfLamps=4&LineVolts=277&Product%20Technology=Linear%20Fluorescent&PRODUCTCODE=71423

Take a look at that. It runs four 32W T8 lamps at ballast factor of 1.0, which means that each lamp is driven to push 100% of rated output. The input power is 121W, which is actually less than 4 x 32W. The power received by lamps is even less, because the ballast is obviously not 100% efficient. It is in the 90s%. So, at 92% ballast efficiency, the lamps will get 111.3W, or 27.83W each, but the lamps will produce the same output as when driven at 32.0W at line frequency. 

Since lamps gain efficacy at 10s of KHz compared to 60Hz, it's possible for them to produce the rated output at less than rated 60Hz wattage. 

27.83W/32.0W = 0.87
1/0.87 =1.149.. so it looks like the lamps are gaining efficacy by about 15% due to high frequency drive. Give or take a few percents since the ballast efficiency was guessed. 

According to 5th edition of IESNA Lighting Handbook 8-3, 40W 48" lamp gains 12.5% @ 10,000Hz relative to 60Hz. Your common F40T12 will produce the same output by re-rating it to 35.5W high freq. 

T5s are rated at HF, so when you take catalog lumens and divide by rated catalog watts, you'll have higher lumens per watt. The people who market T5s leverage this as "T5s are more efficient" 

The best T8 lamp, the Sylvania XPS gives 3200 lumens initial, 3050 lumens mean
http://ecom.mysylvania.com/miniapps/NewandFeaturedProducts/MayNewProducts/SPHSS/SPHTS OCTRON XPS.pdf

Mean lamp efficacy from whats ballast delivers to the lamp is close to 110 lumens per watt at high frequency, but no ballast has the capability of delivering line power to lamps with zero loss. System efficacy is around 101 lumens per watt, that's taking ballast loss into consideration. These are based lamp and ballast data provided above. 




> I had a chance to watch the video you posted, for some reason it didn't show up when I posted my original response. Why do you say that the modification is "more work" than a ballast change out? It looks identical to a ballast change out.


For one, the wiring is proprietary so there is employee learning curve. Second, there's an additional step at each lamp spot in installing the specialized integral ballast adapter in addition to installing the lamp. 

If you've already got a working T8 ballast, 30W high efficacy lamps can be installed to reduce wattage while maintaining the same output only at the cost of new lamps + labor. 

If you're going to do a ballast swap, I'm pretty certain high efficiency T8 ballasts are cheaper than that adapter.

The LUM adapter thing is setup for one ballast per lamp, and 28W lamps are driven at 95% consuming 31W


Advance-Philips Optanium line premium high efficiency T5 ballast for F25T5
IOP2S2895SC
two lamps and consumes 58W at 277v (59W at 120v) @ 95% BF 

FP28841PMECO 20944 is rated at 2900 mean lumens as published by Sylvania. Life is only 20,000 hours @ 3 hour cycle

2900 lumen * 2 lamps * 0.95 BF/58W) = 95 system LPW. 
T8 system I mentioned earlier offers 101 LPW system efficacy based on mean lumen values, so The T5 actually falls short by 6%, but that's using one of the most efficient ballast. The gimmick adapter ballast maybe significantly less efficient. 

Lamp is rated at HF and raw mean efficacy is 103.6LPW, so it appears that Advance-Philips ballast is 91.6% efficient, which is about right for a premium efficiency ballast. 

That LUM adapter is rated at 0.95BF @ 31W with one 28W lamp. 
2900 lumen(mean, not initial) * 0.95 / 31W =88.9 system LPW using the best lamp out there. Even worse. Not bad, but not as good as T8 and its not what its marketing materials make it out to be. It forgot to mention it is 12% less efficient than the best T8 system. 

T5s are not produced as many, unit cost of lamps are higher. That gimmick retrofit adapter is probably more expensive than a T8 ballast. The above figures are using premium lamps with premium ballast. 

I used mean lumen values in all of the calculations, for both T8 and T5. Lamps don't remain brand new after they're used, so I don't use initial values.

I see you just registered. Are you sure you're not someone from the gimmick manufacturer who came here after seeing this thread was the referring URL to the site?


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## FutureLED (May 15, 2010)

Electric_Light said:


> I fix my errors when I spot them. As I said, I made an error.


Your original post here was specifically about T5 *LAMP* efficacy in comparison to T8 and T12, and that is what I responded to.

Now you are moving onto system efficacies (ballast + lamp). That is a different discussion. However, comparing a 4-lamp T8 ballast where the ballast waste is shared among 4 lamps to a 1-lamp T5 ballast system isn't comparing apples to apples.

If we are going onto system efficiencies, then we need to proceed onto optical efficiencies, thermal efficiencies, and fixture efficiencies. Lets step into thermal efficiencies. T8 and T12 are most efficient at an ambient temperature (at the bulb wall) of 77def F. T5 is most efficient at 95 - 98 deg F. In a ceiling recessed office environment an open parabolic fixture will typically be around 90def F, a closed acrylic lensed fixture will be closer to 100def F. At these temperatures T8 and T12 will lose about 10% of its light output, whereas T5 will be in its ideal zone. This is a significant variable that is very rarely mentioned.



Electric_Light said:


> The best T8 lamp, the Sylvania XPS gives 3200 lumens initial, 3050 lumens mean
> http://ecom.mysylvania.com/miniapps/NewandFeaturedProducts/MayNewProducts/SPHSS/SPHTS OCTRON XPS.pdf
> 
> Mean lamp efficacy from whats ballast delivers to the lamp is close to 110 lumens per watt at high frequency, but no ballast has the capability of delivering line power to lamps with zero loss. System efficacy is around 101 lumens per watt, that's taking ballast loss into consideration. These are based lamp and ballast data provided above.


The link to Sylvania that you provided contradicts almost everything that you have stated so far. To start, mean lumens is a measure of the light output at 40% of lamp life. In the Sylvania brochure they state the mean lumens listed is measured at only 8,000 hours. You state above that the mean lumens is 3050, the spec sheets states it is 3040 at 8,000 hours, the true mean lumens at 40% lamp life is actually 2976 lumens. Per their brochure, "95% @ 8,000 hours. Lumen maintenance 94% @ 9,600 hours, 93% @ 12,000 hours (40% of rated life).".

Second, you stated prior that big T8 lamp life is always based on Instant Start ballasts in spec sheets. However, per this Sylvania brochure "Lamp life based on operation on dedicated QUICKTRONIC programmed rapid start ballast.".

Lastly, you stated that T8 lumen output is always based on reference ballasts running at line frequency. However, in this Sylvania brochure the T8 lamp lumen measurements are using an HF ballast. They even have a section showing mean lumen output for a 2-lamp system using their 3,200 lumen lamp and their own Quicktronic HF ballasts. One using their Instant Start ballast which shows a ballast-bulb system efficacy of 92 lm/w and one using their Program Start ballast which shows an efficacy of 94 lm/w. However, these numbers are based on the mean lumens at only 8,000 hours. Using an industry standard mean lumens at 40% lamp life the efficacies are really 89.8 lm/w and 91.8 lm/w respectively. This is a far cry from your calculated 101 lm/w efficacy.

As long as we are searching out the "best", here is a T5 lamp that gets 116 lm/w (110 lm/w at mean lumens), lasts 58,000 hours, and runs at 25W:

http://aura-light.co.uk/images/products/productleaflets/international/T5EcoSaver_INT.pdf



Electric_Light said:


> 2900 lumen * 2 lamps * 0.95 BF/58W) = 95 system LPW.
> T8 system I mentioned earlier offers 101 LPW system efficacy based on mean lumen values, so The T5 actually falls short by 6%, but that's using one of the most efficient ballast. The gimmick adapter ballast maybe significantly less efficient.
> 
> Lamp is rated at HF and raw mean efficacy is 103.6LPW, so it appears that Advance-Philips ballast is 91.6% efficient, which is about right for a premium efficiency ballast.


As I have shown the Sylvania lamp isn't anywhere near 101 lm/w, so all of your figures above are not valid. Using the adjusted figures the T5 system is 5% more efficient than the Sylvania T8 system. If you are going to reference the GE ballast above, you need to do a comparison between a 2-bulb T8 ballast if you are going to compare it to a 2-bulb T5 ballast. The overall ballast waste is less in a 4-bulb than a 2-bulb ballast.

If we don't conveniently stop at the ballast+bulb efficacy and add in thermal efficiency in the most widely used application of linear fluorescent bulbs, the ceiling recessed fixture, the T8 system will lose 10% of its efficacy, placing that (incorrect) 101 lm/w down to 91 lm/w. This is not even taking into account the better optical efficiency of the smaller T5 bulb and the potential better fixture efficiency.



Electric_Light said:


> T5s are not produced as many, unit cost of lamps are higher.


Early on T8 bulbs were more expensive than T12 and as they became more popular the prices came down, there should be no reason why the same won't happen with T5. In equal volume T5 should be less costly as there is far less material needed for their manufacture. T5 is already very popular in both Europe and Asia where they are displacing T8.



Electric_Light said:


> I see you just registered. Are you sure you're not someone from the gimmick manufacturer who came here after seeing this thread was the referring URL to the site?


My interest posting here is strictly related to discussing the differences between T8/T12 and T5 technology, as you can see in my original post. I would suspect someone representing the manufacturer of the product you panned would be far more interested in defending their product. Since I don't own any of their products it is impossible for me to fairly evaluate it and come to any conclusion. However, in the viewing of the video provided I would prefer to use a system that shares a single ballast between multiple bulbs as the ballast waste would be shared between the bulbs, leading to better efficacy. I do believe that the general idea of a retrofit to T5 is not a "gimmick" if it is done properly, and does offer several advantages over T12 and T8 systems.


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## Electric_Light (Apr 6, 2010)

FutureLED said:


> Your original post here was specifically about T5 *LAMP* efficacy in comparison to T8 and T12, and that is what I responded to.


Ok... and T5 vs T8, no appreciable difference. If anything T8 came out better. 



> Now you are moving onto system efficacies (ballast + lamp). That is a different discussion. However, comparing a 4-lamp T8 ballast where the ballast waste is shared among 4 lamps to a 1-lamp T5 ballast system isn't comparing apples to apples.


Good point, and that is another reason why that gimmick is wasteful by installing one ballast per lamp in a multi-lamp fixture. 



> 8 and T12 are most efficient at an ambient temperature (at the bulb wall) of 77def F. T5 is most efficient at 95 - 98 deg F. In a ceiling recessed office environment an open parabolic fixture will typically be around 90def F, a closed acrylic lensed fixture will be closer to 100def F. At these temperatures T8 and T12 will lose about 10% of its light output, whereas T5 will be in its ideal zone. This is a significant variable that is very rarely mentioned.


The 32W F32T8 is given a 20-30C sweet zone, the 25W energy saver 4' T8 is given 30-40C according to Philips fluorescent catalog p.95. Same length different wattage. Just like 32W T8 vs 28W T5. Again, its not like T5 is a different "technology". The F25T5 841 and F32T8 841 basically have the same phosphor and different envelope. 



> 3040 at 8,000 hours, the true mean lumens at 40% lamp life is actually 2976 lumens.


It's their sell sheet after all :001_huh: apparently they must have got a little creative. I'll give ya that 2.2%. 



> Second, you stated prior that big T8 lamp life is always based on Instant Start ballasts in spec sheets.


They usually are. 



> Lastly, you stated that T8 lumen output is always based on reference ballasts running at line frequency. However, in this Sylvania brochure the T8 lamp lumen measurements are using an HF ballast.


The lamp outputs are. The table compares output in various combination, but a bare lamp is based on being given rated wattage at 60Hz to produce that output. It's not explicitly stated in catalog. A F32T8 with 3,200 lamp lumens means that it will produce 3,200 lumens when it is driven at 32.0W on a reference ballast (60Hz). 

System lumen is lamp lumen x ballast factor. If lamps were operating at line frequency, it would need to operate at 32.0W to get 1.0. Less than 32W to get 1.0 at HF. 




> As long as we are searching out the "best", here is a T5 lamp that gets 116 lm/w (110 lm/w at mean lumens), lasts 58,000 hours, and runs at 25W:
> 
> http://aura-light.co.uk/images/products/productleaflets/international/T5EcoSaver_INT.pdf


Never even heard of them and I don't trust the data. 
Philips offers T8 that gets 40,000 hours on IS and 46,000 hours on PRS on 12 hour cycle though. They're not as efficacious as the highest efficacy lamps though. 



> As I have shown the Sylvania lamp isn't anywhere near 101 lm/w, so all of your figures above are not valid. Using the adjusted figures the T5 system is 5% more efficient than the Sylvania T8 system. If you are going to reference the GE ballast above, you need to do a comparison between a 2-bulb T8 ballast if you are going to compare it to a 2-bulb T5 ballast. The overall ballast waste is less in a 4-bulb than a 2-bulb ballast.


You're an idiot to install four one lamp ballasts into one four lamp fixture. Unfortunately, with the gimmick T5 adapter, one ballast per lamp is the only option. 



> If we don't conveniently stop at the ballast+bulb efficacy and add in thermal efficiency in the most widely used application of linear fluorescent bulbs, the ceiling recessed fixture, the T8 system will lose 10% of its efficacy, placing that (incorrect) 101 lm/w down to 91 lm/w.


The electrical input doesn't stay constant, so they don't necessarily lose 10% efficacy. Also, as mentioned already, 25W 4' T8s have 10*C higher sweet spot.



> This is not even taking into account the better optical efficiency of the smaller T5 bulb and the potential better fixture efficiency.


"potential better"... oh come on :whistling2:




> I do believe that the general idea of a retrofit to T5 is not a "gimmick" if it is done properly, and does offer several advantages over T12 and T8 systems.


The claims made in their sell sheet is clearly gimmicky. The differences between T8 and T5 are negligible.

And just for the record, Philips, GE and Sylvania all offer T8s as well as T5s and T5s are not sold as magically better than T8s

I didn't say T5s are inferior, but Lumiversal is clearly making T5s a big deal.

T5 claims by Lumivesal: 
"Lasts up to 25,000 hours, therefore reducing
maintenance needs and costs. "
Normal T8s last 24,000 hours @ 3hrs cycle in IS or 30,000 @ 12 hrs 30,000/36,000 on PRS



> o Reduces lumen depreciation to only 5% in
> comparison to T12 and T8 bulbs’ 30% lumen
> depreciation.


The 5% figure is also true for T8s too.




> o Consumes up to 50% less energy than T12/T8 bulbs.
> o Emits Up to 25% less heat than T12/T8 bulbs, reducing


This is hogwash.


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## FutureLED (May 15, 2010)

Electric_Light said:


> Ok... and T5 vs T8, no appreciable difference. If anything T8 came out better.


Please explain again to me how T8 came out better? Using spec sheets they don't, using your magical 10% formula to apply to T8 spec sheets they don't either. From GE/Sylvania/Philips the most efficient T8 bulb is 3100 lumens. Applying your 10% gives it 3410 lumens. At 32W this is 106.5 lm/w. The best from GE on T5 is 112 lm/w.



Electric_Light said:


> Good point, and that is another reason why that gimmick is wasteful by installing one ballast per lamp in a multi-lamp fixture.


You keep going back to this companies products rather than focusing on the discussion of T5 vs T8 technology. I would rather keep this discussion on the fluorescent technology. However, since you keep treading there, looking at the link to the spec sheet you provided that company clearly has an alternate solution that shares a single ballast between multiple bulbs. From the wording in that spec sheet it appears they recommend that solution for multi-bulb systems.



Electric_Light said:


> The 32W F32T8 is given a 20-30C sweet zone, the 25W energy saver 4' T8 is given 30-40C according to Philips fluorescent catalog p.95. Same length different wattage. Just like 32W T8 vs 28W T5. Again, its not like T5 is a different "technology". The F25T5 841 and F32T8 841 basically have the same phosphor and different envelope.


It is very convenient to use manufacturers specs and trust them implicitly. Interesting how the chart from Philips on thermal efficiency of a standard T8 bulb is vastly different on separate pages of their same brochure. On Page 95 it shows a standard T8 bulb as maintaining 95% lumen output at 39deg C. But, on page 102 it shows a standard 32W T8 bulb as only maintaining about 88% lumen output at 39deg C. Which do you believe?

I tend to believe independent 3rd parties with no skin in the game. The Lighting Research Center at Rensselaer Polytechnic Institute published a paper specifically about T5 and T8, from the paper:

"One of the most significant factors affecting lamp light output is ambient temperature. Table 1-7 summarizes light outputs and efficacies of nominal four-foot standard T5, T5 HO, and standard T8 lamps. Manufacturers usually provide light output data at the optimal temperature for each lamp type in their catalogs: 35°C (95°F) for the standard T5 and T5 HO lamps and 25°C (77°F) for the T8 lamps. Light output data for T5 lamps at 25°C (77°F) and for T8 lamps at 35°C (95°F) are also available from manufacturers, however. Table 1-7 shows that, at 25°C (77°F), the light output of T8 lamps is higher than the standard T5 lamps. At 35°C (95°F), however, the standard T5's light output is higher than that of the T8 lamp. With respect to lamp efficacy, the standard T5 lamps are more efficacious than the standard T8 lamps at 35°C (95°F), but the two types of lamps are nearly identical at 25°C (77°F)."

The table in the report shows that at 35C a T8 32W bulb loses 8% of its lumen output. It also shows that using HF ballasts at 35C the T5 lamp-ballast system has a system efficacy of 94 lm/w and the T8 lamp-ballast system has a system efficacy of 83 lm/w. For comparison, the same T8 system has a system efficacy of 90 lm/w at 25deg C, showing a clear loss of 8% in overall efficiency as we get into the temperature zone of most commercially installed lighting.

In regards to the 25W T8 bulbs that are designed to be most efficient at 35C there is some significant differences in this technology compared to T5, and some significant downsides to this 25W T8 bulb. 25W T8 bulbs typically use a 100% Krypton gas filling. This leads to pretty significant striations and starting problems at lower temperatures. Also, it is problematic to dim these bulbs. Thus the reason most manufacturers don't recommend using the 25WT8 in an outdoor installation or in an installation that employs dimming. So, as daylight harvesting systems become more popular 25WT8 bulbs won't be an option in their current state.



Electric_Light said:


> The lamp outputs are. The table compares output in various combination, but a bare lamp is based on being given rated wattage at 60Hz to produce that output. It's not explicitly stated in catalog. A F32T8 with 3,200 lamp lumens means that it will produce 3,200 lumens when it is driven at 32.0W on a reference ballast (60Hz).
> 
> System lumen is lamp lumen x ballast factor. If lamps were operating at line frequency, it would need to operate at 32.0W to get 1.0. Less than 32W to get 1.0 at HF.


No, the lamp outputs aren't. In that Sylvania spec sheet the 3,200 output lumens are based on an HF ballast as can clearly be seen by the table calculating output lumens on a 2-bulb system using an HF ballast. In any event, the catalog you posted was from 2001, Sylvania has an updated spec sheet where the same bulb now puts out 3,100 initial lumens instead of 3,200:

http://www.goodmart.com/pdfs/FL038.pdf

Again, the calculations on that spec sheet using HF ballasts clearly show that the stated 3,100 lumen output is based on a HF ballast, not a line frequency ballast, and thus the 10% additive lumens you are counting on by using an HF ballast don't apply.



Electric_Light said:


> You're an idiot to install four one lamp ballasts into one four lamp fixture. Unfortunately, with the gimmick T5 adapter, one ballast per lamp is the only option.


Interesting that you would resort to a personal attack, I never called you an idiot for all the mistakes you have made thus far. Further odd since I have never advocated doing such a thing, in fact i advocated just the opposite. I also don't know under what circumstance one would retrofit to 4 T5 bulbs in a single fixture.




Electric_Light said:


> "potential better"... oh come on :whistling2:


With greater optical efficiency smaller more efficient fixtures can be designed, this is a fact supported by several industry papers. I don't have the time right now to search out those papers to cite and therefore fell back on stating "potentially".



Electric_Light said:


> I didn't say T5s are inferior, but Lumiversal is clearly making T5s a big deal.


You absolutely did, multiple times.


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## Electric_Light (Apr 6, 2010)

I don't have time right now... let me deal with this later.


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## MDShunk (Jan 7, 2007)

Watching two lighting guys having a debate is like watching a fight between Peewee Herman and Steve Urkel.


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## Bob Badger (Apr 19, 2009)

This is awesome.:thumbsup:



Electric_Light said:


> I don't have time right now... let me deal with this later.


I think LED derailed your train which strikes me very funny.:thumbup:


*Propose an LED based general lighting*


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## NolaTigaBait (Oct 19, 2008)

MDShunk said:


> Watching two lighting guys having a debate is like watching a fight between Peewee Herman and Steve Urkel.


 I was thinking that...Each response was as long as War and Peace....


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## FutureLED (May 15, 2010)

MDShunk said:


> Watching two lighting guys having a debate is like watching a fight between Peewee Herman and Steve Urkel.


:laughing: I am not sure which I would rather be in this debate.


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## Electric_Light (Apr 6, 2010)

FutureLED said:


> Please explain again to me how T8 came out better? Using spec sheets they don't


They did in the system efficacy comparing the gimmick vs GE.



> magical 10% formula to apply to T8 spec sheets they don't either.


Make that 12.5%. That is closer to efficacy gain for four foot lamp as shown in IES Lighting Handbook, yes this is an independent resource. 

Now, using same # of lamp combination, and same brand lamps + ballasts, the efficacy between T5 and T8 are about the same. 

T5 system, two GE lamp with two lamp GE ballast, 277v 
http://genet.gelighting.com/LightPr...chnology=Linear Fluorescent&PRODUCTCODE=99655
99lm/W new, 91.4 lm/W mean

T8 system, same as above. 
http://genet.gelighting.com/LightPr...chnology=Linear Fluorescent&PRODUCTCODE=72267
101 lm/W new, 95.7 lm/W mean 




> You keep going back to this companies products rather than focusing on the discussion of T5 vs T8 technology.


You keep making them seem like they're different technologies. 



> On Page 95 it shows a standard T8 bulb as maintaining 95% lumen output at 39deg C. But, on page 102 it shows a standard 32W T8 bulb as only maintaining about 88% lumen output at 39deg C. Which do you believe?


hmm no idea. They probably screwed up in one place. 
On another one of their literature though, the T5 shows optimal output at higher temperature, but T8s do better at lower ambient. 
http://www.lighting.philips.com/us_en/browseliterature/download/p-5123.pdf




> I tend to believe independent 3rd parties with no skin in the game. The Lighting Research Center at Rensselaer Polytechnic Institute published a paper specifically about T5 and T8, from the paper:


The lamps cited in that paper is from catalogs almost a decade ago. 



> In regards to the 25W T8 bulbs that are designed to be most efficient at 35C there is some significant differences in this technology compared to T5, and some significant downsides to this 25W T8 bulb. 25W T8 bulbs typically use a 100% Krypton gas filling. This leads to pretty significant striations and starting problems at lower temperatures.


In lower temperature, a standard T8 wouldn't be an issue to begin with. It isn't about whats better, its about whats appropriate. Your objection was that T8s supposedly run beyond their optimal temperature in indoor lighting applications. 



> Interesting that you would resort to a personal attack, I never called you an idiot for all the mistakes you have made thus far. Further odd since I have never advocated doing such a thing, in fact i advocated just the opposite. I also don't know under what circumstance one would retrofit to 4 T5 bulbs in a single fixture.


I didn't mean YOU specifically, silly. I meant anyone putting four one lamp ballast is, but that's the outcome when those gimmick adapters are installed.


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## FutureLED (May 15, 2010)

Electric_Light said:


> They did in the system efficacy comparing the gimmick vs GE.


Debating with you is turning into an exercise in futility. You flip flop from comparing T5 to T8/T12 technology to comparing different manufacturers very different implementations of that technology, specifically choosing a (very beneficial to T8) apples to oranges comparison to suit your position. It is ridiculous to support your position by taking a 4-bulb T8 ballast-lamp system which shares waste between 4 bulbs and comparing it to a single-lamp T5 ballast-lamp system.



Electric_Light said:


> Now, using same # of lamp combination, and same brand lamps + ballasts, the efficacy between T5 and T8 are about the same.
> 
> T5 system, two GE lamp with two lamp GE ballast, 277v
> http://genet.gelighting.com/LightPr...chnology=Linear Fluorescent&PRODUCTCODE=99655
> ...


You leave out the 26W GE T5 bulb that is more efficient than the 28W versions in that spec sheet, which would push the initial efficacy to 102 lm/w. These figure also don't take into account any loss at 35C for the T8.

But, as always, the devil is in the details. Look further at the GE T8 ballast-lamp systems. The lamps that achieve the 101 lm/w initial lumen efficacy have serious problems with lumen maintenance over the life of the bulbs. For example:

http://genet.gelighting.com/LightProducts/Dispatcher?REQUEST=COMMERCIALSPECPAGE&PRODUCTCODE=10327

Even though 2915 is listed as the mean lumens, there is a chart showing the lumen maintenance of the lamp. At just 1/3 life the lamp has lost around 8% of its lumens. At 1/2 life it has lost about 12%. At 2/3 life it is around 15% lumen loss. So, any marginal initial efficacy advantage of the T8 in your example is quickly lost and continues to lose further over the life of the bulb. All of the 3100 initial lumen GE bulbs have this same lumen depreciation chart.



Electric_Light said:


> The lamps cited in that paper is from catalogs almost a decade ago.


As are lamps you have cited in prior posts as being the "best currently".



Electric_Light said:


> I didn't mean YOU specifically, silly. I meant anyone putting four one lamp ballast is, but that's the outcome when those gimmick adapters are installed.


A quick scan of that companies website shows they recommend their shared-ballast solution for multi-bulb fixtures. So, I don't really know anybody, other than you, that is suggesting anybody would install 4 one-lamp ballasts into single fixture. I certainly wouldn't, i wouldn't expect a competent ESCO or lighting retrofit contractor to do so either. In the end you are trying to make a case of an unrealistic installation scenario to support your contention that the companies product is a "gimmick".

As long as we are on that track, here is GE's T5 lighting brochure:

http://genet.gelighting.com/LightProducts/images/t04/0000000/r00357v-1.pdf

Take note how they state a 32W T8 has 2,800 initial lumens and compares that to 3,050 initial lumens of T5 without any of your correction factors. They even go further to state ballast-lamp lumens for T8 without any correction factors. This is the same you are accusing the company you call a "gimmick" of. I trust you are equitable in your criticisms and will refer to GE in the future as "that gimmick company" as well.


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## Electric_Light (Apr 6, 2010)

FutureLED said:


> Debating with you is turning into an exercise in futility. You flip flop from comparing T5 to T8/T12 technology to comparing different manufacturers very different implementations of that technology, specifically choosing a (very beneficial to T8) apples to oranges comparison to suit your position. It is ridiculous to support your position by taking a 4-bulb T8 ballast-lamp system which shares waste between 4 bulbs and comparing it to a single-lamp T5 ballast-lamp system.


I showed you a 2 lamp T5 vs 2 lamp T8 _system efficacy_ to neuter the effect of HF vs line frequency measurement difference used in lamp specs. They results are about the same. There's ballast to ballast, lamp to lamp difference, but not clear distinct benefit/harm of T5 over T8. 




> You leave out the 26W GE T5 bulb that is more efficient than the 28W versions in that spec sheet


I left out the 26W Watt-Miser Just as I left out T8 48" 25 and 28W energy savers. I'm comparing with just full watt lamps. 



> These figure also don't take into account any loss at 35C for the T8.


And vice versa. T5 system efficacy don't take into getting too cold in a cooler ambient temperature as seen in open luminaires used indoors.



> But, as always, the devil is in the details.So, any marginal initial efficacy advantage of the T8 in your example is quickly lost and continues to lose further over the life of the bulb. All of the 3100 initial lumen GE bulbs have this same lumen depreciation chart.


Seems to me it's lamps vs lamps, rather than T5 bulb vs T8 bulb. I'm seeing 95% @ 20,000 hrs on Philips XLL and 93% @ end of life of 40,000 hrs (3hrs, Prog start).

T5 vs T8 isn't a technological difference. It's 5/8" tube vs 1"(8/8") , nothing else. 




> A quick scan of that companies website shows they recommend their shared-ballast solution for multi-bulb fixtures. So, I don't really know anybody, other than you, that is suggesting anybody would install 4 one-lamp ballasts into single fixture.


That video shows using multiple one-lamp-to-one-ballast LUM adapter thing. 



> contention that the companies product is a "gimmick".


It's only a gimmick because of the hyper-inflated claims made in their marketing literature, generous use of "*up to*", "compared to the average/most" etc trying to get people to spend money on something that might as well be comparable by creative use of "UP TO" statements. 



> Take note how they state a 32W T8 has 2,800 initial lumens and compares that to 3,050 initial lumens of T5 without any of *your correction factors.*


What you keep missing is that T5 lamps were never meant to be operated on line frequency and the specs are based on high frequency, so the specs are already taking advantage of efficacy gain offered by HF drive.

T8 and T12 specs are still based on 60Hz operation. The efficacy gain factor is shown in IES Lighting Handbook, a well respected neutral reference. 

Take a look at how they didn't explicitly state the difference in reference ballasts. Again, this is the difference T5 sales people keep exploiting.

T5 vs T8 is something to consider for new install... T5 is nothing special that you should even think about gutting existing T8 fixtures of its ballasts and installing patch-up adapter.


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## FutureLED (May 15, 2010)

Electric_Light said:


> I showed you a 2 lamp T5 vs 2 lamp T8 _system efficacy_ to neuter the effect of HF vs line frequency measurement difference used in lamp specs. They results are about the same. There's ballast to ballast, lamp to lamp difference, but not clear distinct benefit/harm of T5 over T8.


But... Devil in the details again. You showed me a 2 lamp "Instant Start" T8 system vs a 2 lamp "Program Start" T5 system. Program Start ballasts are slightly less efficient than Instant Start ballasts, but enable 50,000+ starts vs 15,000 starts. As I mentioned before, you have moved beyond your original post about lamp efficiency to lamp-ballast efficiency. But, you conveniently stop there and don't consider all efficiencies in a complete T5 and T8 system. In the end T5 wins against T8 in almost all scenarios. And, the end is all that matters.



Electric_Light said:


> And vice versa. T5 system efficacy don't take into getting too cold in a cooler ambient temperature as seen in open luminaires used indoors.


Amalgam mercury encapsulation that was started in T5HO lamps and now has been successfully tested in HE lamps removes a significant amount of temperature sensitivity in T5 lamps. It is exactly advances like this in T5 technology that enables it to surpass T8 technology which doesn't work as well using amalgam.



Electric_Light said:


> Seems to me it's lamps vs lamps, rather than T5 bulb vs T8 bulb. I'm seeing 95% @ 20,000 hrs on Philips XLL and 93% @ end of life of 40,000 hrs (3hrs, Prog start).


You are back to quoting standard lumen output lamps, which the XLL are. My comments were regarding the high lumen T8 lamps shown in the GE literature that you used to compare against T5. The high lumen and high efficiency T8 lamps appear to have some issues which are swept under the rug in marketing materials.



Electric_Light said:


> T5 vs T8 isn't a technological difference. It's 5/8" tube vs 1"(8/8") , nothing else.


This is a very simple minded, very incorrect, statement. You could just as easily say the same about T12 vs T8, it is a 12/8" tube vs a 8/8" tube, but we all know T12 has been left as a relic. I will tell you exactly why, and why the tube diameter has a significant impact in the "technology" of fluorescent lamps.

In order to increase the efficiency of the lamps Krypton, among other noble gasses, were used as a mixture with Argon, in various ratios. However, using these other gases lowered the internal resistance which resulted in lower voltages on the cathodes. The end result was the lamps ran too dim with standard ballasts. Reducing the bulb diameter, going from 1.5" to 1.0" (T12 -> T8), increases cathode/filament voltage, and enabled the use of these alternate gasses which enabled higher efficiency while maintaing proper voltages to get proper light output. In other words, these gas mixtures could NOT be applied to a T12 tube, the tube diameter had to be reduced to support them.

The same is going on now. The next "big" thing for fluorescent is Xenon gas mixtures. These are estimated to bring up efficacy of fluorescent to 120 - 150 lm/w. However, the Xenon mixtures lower voltages even further making them more ideal for the smaller diameter of T5 lamps. So, much like T12 has hit a cement wall, T8 will also hit that wall in the efficacy wars.

So, keep on believing that there is no difference between T12, T8, and T5 except for the tube diameter. You will be the equivalent of some guy trying to tell everybody today that T12 is the wave of the future.



Electric_Light said:


> T5 vs T8 is something to consider for new install... T5 is nothing special that you should even think about gutting existing T8 fixtures of its ballasts and installing patch-up adapter.


I completely disagree.

First, removing a ballast and replacing it with a ballast, or similar device, is hardly "gutting" a T8 fixture. It is a completely reversible process and a process anybody skilled in ballast replacement can do in 10 minutes or less.

When taking into account all parameters T5 is an overall better solution from an efficacy standpoint, than T8, for the majority of where T8 is used today, the ceiling-recessed office environment. Going to T5 the customer will also have a program start ballast for when eventually all switches are motion based. From a "green" perspective nearly half the materials used to manufacture a T8 are used to manufacture a T5, and from a maintenance/storage perspective you can store 2-3 T5 lamps in the same space as 1 T8 bulb.

In the next few years as T5 lamps come out using Xenon gas mixtures that push new efficacy records people that are already T5 simply would need to purchase a new bulb to realize those new efficiencies, whereas T8 will be left in the dust as has been the case with T12.

It is pretty clear that you make your living on spec'ing advance T8 retrofit solutions and that is where your mind is at. You aren't open to any other solution, no matter what the specifications state. Going back to your original post, it was full of unsubstantiated hyperbole which you later retracted. In follow-up posts when you can't make your case on a technology basis you start comparing apples to oranges on different companies products.

This discussion reminds me of when I debated with others when T8 first came out and they were dead-set on T12 and didn't see any point to T8. Here we are again full circle. Technology advances and these advances should be embraced rather than rebuked, but there are always those that want to hang onto the old. LED, at some point, from both an efficacy and price perspective will overtake fluorescent and that is the the reality of the future.


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## Electric_Light (Apr 6, 2010)

:ugh: 
stop calling lamps "bulbs"


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## Electric_Light (Apr 6, 2010)

FutureLED said:


> But... Devil in the details again. You showed me a 2 lamp "Instant Start" T8 system vs a 2 lamp "Program Start" T5 system. Program Start ballasts are slightly less efficient than Instant Start ballasts, but enable 50,000+ starts vs 15,000 starts.


The area available for filament surface is smaller on a T5 due to a smaller glass bulb, so they're not as resilient as something that can be made to T8 size. PRS ballasts are there for T8, but they're seldom used, only in dimming and frequently switched places. 



> lamp efficiency to lamp-ballast efficiency.


Efficiency =! efficacy, bulb =! tube. I wonder you and Lumiversal literature have those mistakes in common. :jester:



> In the end T5 wins against T8 in almost all scenarios. And, the end is all that matters.


 I'm not sure how you came to that conclusion. I disagree. They're about the same. 




> Amalgam mercury encapsulation that was started in T5HO lamps and now has been successfully tested in HE lamps removes a significant amount of temperature sensitivity in T5 lamps. It is exactly advances like this in T5 technology that enables it to surpass T8 technology which doesn't work as well using amalgam.


Amalgam is used mainly for higher energy density lamps like CFLs. Many CFLs, extreme temperature use high output T5 and very high output T8 are some examples. Though not as bad as metal halide, they're slow to warm up in exchange for ability to maintain output at high temperature.




> This is a very simple minded, very incorrect, statement. You could just as easily say the same about T12 vs T8, it is a 12/8" tube vs a 8/8" tube, but we all know T12 has been left as a relic.


That would actually be correct. Since T8 is mainstream right now, not much R&D is devoted to T12 lamps. There is a F40T12 with 3600 lumen rating by Philips. It's rated at 3,600 lumen @ 40W initial, and if you apply the 12.5% factor shown in IES Lighting Handbook, it sits at 101.5 initial LPW efficacy. So no, T8s are not better than T12s and T5s are not better than T8s. There is no appreciable efficacy difference simply because they're T5/T8/T12 whatever. 




> I will tell you exactly why, and why the tube diameter has a significant impact in the "technology" of fluorescent lamps.
> 
> In order to increase the efficiency of the lamps Krypton, among other noble gasses, were used as a mixture with Argon, in various ratios. However, using these other gases lowered the internal resistance which resulted in lower voltages on the cathodes. The end result was the lamps ran too dim with standard ballasts. Reducing the bulb diameter, going from 1.5" to 1.0" (T12 -> T8), increases cathode/filament voltage, and enabled the use of these alternate gasses which enabled higher efficiency while maintaing proper voltages to get proper light output. In other words, these gas mixtures could NOT be applied to a T12 tube, the tube diameter had to be reduced to support them.


Que? Of course changing lamp bulb and fill gas affects electrical properties. This is a matter of ballast/lamp matching. US 48" T8 32W lamps are ~0.26A. European 48 T8s, which they call TL-D are 36W ~0.45A(and will run on F40T12ballasts). Even today, they continue to have different specs. It's not a matter of which one is superior, but they're different, therefore not compatible with each other. 



> The same is going on now. The next "big" thing for fluorescent is Xenon gas mixtures. These are estimated to bring up efficacy of fluorescent to 120 - 150 lm/w.


This sounds even more gimmicky, but I think xenon sounds better than argon on marketing literature. Who estimated that replacing the fill gas raises efficacy in fluorescent lamps and this is relative to what? 



> However, the Xenon mixtures lower voltages even further making them more ideal for the smaller diameter of T5 lamps. So, much like T12 has hit a cement wall, T8 will also hit that wall in the efficacy wars.


Why stick to single 5, lets go for stranded 10 x T0.5 !:laughing:

So, keep on believing that there is no difference between T12, T8, and T5 except for the tube diameter. You will be the equivalent of some guy trying to tell everybody today that T12 is the wave of the future.



> First, removing a ballast and replacing it with a ballast, or similar device, is hardly "gutting" a T8 fixture. It is a completely reversible process and a process anybody skilled in ballast replacement can do in 10 minutes or less.


It's more or less replacing the entire train and the tires. If you keep the old power train and tires, sure, its reversible. It's hardly gutting the car though, right? 



> When taking into account all parameters T5 is an overall better solution from an efficacy standpoint, than T8, for the majority of where T8 is used today, the ceiling-recessed office environment.


Where krypton filled 25W with 10*C higher optimal temp. isn't going to cause complications, even though you cited complications outdoors in the cold. 



> Going to T5 the customer will also have a program start ballast for when eventually all switches are motion based.


Prog. RS has been around for over a decade for use with T8s. It's not something exclusive to T5 like you want me to believe. 



> from a maintenance/storage perspective you can store 2-3 T5 lamps in the same space as 1 T8 bulb.


Obviously, you're going to fit more 5/8" pipes into same box compared to 1" pipes. Whats the point of this?, nice "2-3x" range estimate. 



> Xenon gas


I'm not sure who keeps telling you this Xenon stuff with a capital X. 



> It is pretty clear that you make your living on spec'ing advance T8 retrofit solutions and that is where your mind is at.


It's pretty clear that you're writing on behalf of Lumiversal from the same interchanging of words efficacy and efficiency, as well as calling lamps "bulbs". 



> it was full of unsubstantiated hyperbole which you later retracted. In follow-up posts when you can't make your case on a technology basis you start comparing apples to oranges on different companies products.


T8 to T5 isn't apples to oranges. Even in similar configurations, they were pretty much the same causing you to need to stretch hypothetical temperature situations to stretch the "up to" situation. 



> This discussion reminds me of when I debated with others when T8 first came out and they were dead-set on T12 and didn't see any point to T8.


I'm not sure why the North American T8 lamps aren't made backward compatible with T12 ballasts like they're in Europe. Perhaps to compel, rather than changeover to more efficient HF electronic ballast? 

T12s almost always used cool white phosphor but T8s are made with triphosphor. T8s and T5s are made using the same phosphors (RE8xx) and we're no longer going through magnetic to high frequency changeover. 




> Here we are again full circle. Technology advances and these advances should be embraced rather than rebuked, but there are always those that want to hang onto the old. LED, at some point, from both an efficacy and price perspective will overtake fluorescent and that is the the reality of the future.


Maybe perhaps possibly eventually. I don't expect fluorescent to take over HIDs in stadium lighting just as I don't expect LEDs to take over general lighting.


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## Bob Badger (Apr 19, 2009)

Electric_Light said:


> as I don't expect LEDs to take over general lighting.


IBM thought the idea of PCs for home use was going nowhere.:laughing:


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## BuzzKill (Oct 27, 2008)

MDShunk said:


> Watching two lighting guys having a debate is like watching a fight between Peewee Herman and Steve Urkel.


:laughing::laughing:


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## FutureLED (May 15, 2010)

Electric_Light said:


> The area available for filament surface is smaller on a T5 due to a smaller glass bulb, so they're not as resilient as something that can be made to T8 size.


T5 lamps have been made to exceed 50,000 hours of life, the size of the bulb is irrelevant to filament longevity. Such things as triple-coil filaments and triple-wound filament guards are what is driving lamp life.



Electric_Light said:


> PRS ballasts are there for T8, but they're seldom used, only in dimming and frequently switched places.


Of course PRS ballasts are available for T8, which means when you want to correctly compare the efficacy of T8 vs T5 you could cite examples of apples vs apples, i.e. if you are going to use a 2-lamp PRS T5 example you should use a 2-lamp PRS T8 example, but you conveniently compare different implementations that give an edge to T8.



Electric_Light said:


> That would actually be correct. Since T8 is mainstream right now, not much R&D is devoted to T12 lamps. There is a F40T12 with 3600 lumen rating by Philips. It's rated at 3,600 lumen @ 40W initial, and if you apply the 12.5% factor shown in IES Lighting Handbook, it sits at 101.5 initial LPW efficacy. So no, T8s are not better than T12s and T5s are not better than T8s. There is no appreciable efficacy difference simply because they're T5/T8/T12 whatever.


And the blinders have gone back on. We have already established in prior posts that T5 is now breaking 116 lm/w (112 lm/w from GE), yet 116 lm/w is "not better" than 101 lm/w?!?? Before you apply your correction factors, the F40T12 at 3600 is 90 lm/w, and the best T8 is 32W at 3100 is 97 lm/w. Not better also? You must have been terrible at math in school if 15% and 8% better efficacy is "not better".



Electric_Light said:


> Que? Of course changing lamp bulb and fill gas affects electrical properties. This is a matter of ballast/lamp matching. US 48" T8 32W lamps are ~0.26A. European 48 T8s, which they call TL-D are 36W ~0.45A(and will run on F40T12ballasts). Even today, they continue to have different specs. It's not a matter of which one is superior, but they're different, therefore not compatible with each other.


Que?! A matter of ballast/lamp matching? So, the fill gas that enables T8 to go from 2,900 -> 3,100 lumens is a matter of ballast matching, when in fact no ballast change is needed?!?! Do you really believe what you post?



Electric_Light said:


> This sounds even more gimmicky, but I think xenon sounds better than argon on marketing literature. Who estimated that replacing the fill gas raises efficacy in fluorescent lamps and this is relative to what


There is no estimation going on. Krypton/Argon mixtures clearly raised the efficacy in fluorescent lamps and the inability of T12 lamps to support these mixtures is what is leading them to follow the dodo bird to extinction. We already have a T5 bulb-ballast system running at 110 lm/w efficacy in our lab using advanced technologies that can't be applied to T8.



Electric_Light said:


> Where krypton filled 25W with 10*C higher optimal temp. isn't going to cause complications, even though you cited complications outdoors in the cold.


You conveniently left out dimming. As daylight harvesting becomes more widespread the 25WT8 is unusable. 




Electric_Light said:


> Prog. RS has been around for over a decade for use with T8s. It's not something exclusive to T5 like you want me to believe.


Of course they have, I never said they haven't existed. However, with T8 systems very few are being installed in comparison to instant start. My comment was that if you go to T5 you will have a PRS ballast by default and will already be prepared for if/when you install motion sensing wall switches.



Electric_Light said:


> Obviously, you're going to fit more 5/8" pipes into same box compared to 1" pipes. Whats the point of this?, nice "2-3x" range estimate.


Does it make you happier if I state exactly 2.67 T5 bulbs fit in the same volume as 1 T8 bulb? Does estimating it at 2-3x really ruffle your feathers that much? I already explained the point of it in my previous post.




Electric_Light said:


> I'm not sure who keeps telling you this Xenon stuff with a capital X.


Is that all you are left with to debate? Take a look at a periodic table, is it xe or Xe?




Electric_Light said:


> It's pretty clear that you're writing on behalf of Lumiversal from the same interchanging of words efficacy and efficiency, as well as calling lamps "bulbs".


Nice try, again. But, I suppose you would accuse anybody that takes a stance against your hyperbole as working for Lumiversal, or any one of the other companies that provide solutions to retrofit to T5. I am a lighting engineer and I like to see advances in lighting being implemented. Regardless of inflated claims I like that companies are making T5 retrofit products. I am impartial as to which as long as newer technology is implemented and adopted.



Electric_Light said:


> T8 to T5 isn't apples to oranges. Even in similar configurations, they were pretty much the same causing you to need to stretch hypothetical temperature situations to stretch the "up to" situation.


There is nothing hypothetical about higher ambient temperatures within ceiling recessed fixtures. You conveniently disregard, and call hypothetical, things that would lower the efficacy of T8.



Electric_Light said:


> Maybe perhaps possibly eventually. I don't expect fluorescent to take over HIDs in stadium lighting just as I don't expect LEDs to take over general lighting.


For 2x2 fixtures LED already has already surpassed fluorescent. And, when I say surpassed I am talking the entire chain of efficacy/efficiency all the way through to fixture efficiency. Your blinders have gone back on if you don't expect it to take over general lighting when the price becomes more competitive.


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## NolaTigaBait (Oct 19, 2008)

Jesus Christ do either of you have a job?


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## Bob Badger (Apr 19, 2009)

NolaTigaBait said:


> Jesus Christ do either of you have a job?


Maybe it is just one person around here you never know. :blink:


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## NolaTigaBait (Oct 19, 2008)

Bob Badger said:


> Maybe it is just one person around here you never know. :blink:


Yeah, we have quite a few schizos around here...


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## Electric_Light (Apr 6, 2010)

FutureLED said:


> Is that all you are left with to debate? Take a look at a periodic table, is it xe or Xe?


No, periodic table symbols don't make them proper nouns. We don't say "Air is made of Oxygen, Nitrogen and Argon, and Carbon DiOxide" nor do we say the liquid metal found in thermometer is Hydragyrum. 

That was not my main point anyhow. Where did the claim xenon fill gives a magical substantial efficacy gain? 



> For 2x2 fixtures LED already has already surpassed fluorescent.


No it hasn't. They're called LUMINAIRES.



> And, when I say surpassed I am talking the entire chain of efficacy/efficiency all the way through to fixture efficiency.


Luminaire system efficacy is something in the 70s lumens per watt on the Cree 2 x 2. On par, or slightly below best T8 system. LEDs are also rated to 70% maintenance over 50,000 hours. The luminaire is also like $500.


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## FutureLED (May 15, 2010)

Electric_Light said:


> No, periodic table symbols don't make them proper nouns. We don't say "Air is made of Oxygen, Nitrogen and Argon, and Carbon DiOxide" nor do we say the liquid metal found in thermometer is Hydragyrum.
> 
> That was not my main point anyhow. Where did the claim xenon fill gives a magical substantial efficacy gain?
> 
> ...


All you can do is argue semantics now? In regards to Xenon fill, once all patents are filed the pertinent information will come out.




Electric_Light said:


> Luminaire system efficacy is something in the 70s lumens per watt on the Cree 2 x 2. On par, or slightly below best T8 system. LEDs are also rated to 70% maintenance over 50,000 hours. The luminaire is also like $500.


The CREE 2x2 not only attained 79 lm/w it also had a CRI of 89 as tested in the latest DOE CALiPER report. The 2x2 T8 luminaire tested at the same time by the DOE had an efficacy of between 44-49 lm/w with a CRI of 81-86. Even if they used the worst T8 lamps in the report the best T8 lamps won't get it anywhere close to 79 lm/w. So, no, the CREE is not on par or slightly below the best T8 system when considering all the way through to 2x2 "luminaire system efficacy", it is substantially better.

The CREE is over $500, but I already stated that the price doesn't make sense yet. The discussion was on efficacy and whether LED lighting would take over general lighting, eventually.


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## Electric_Light (Apr 6, 2010)

FutureLED said:


> regards to Xenon fill, once all patents are filed the pertinent information will come out.


This is where I say OK, whatever you say. :laughing:




> The CREE 2x2 not only attained 79 lm/w it also had a CRI of 89 as tested in the latest DOE CALiPER report.


I think the CREE 2x2 is one of the best LED troffer available. The LM-79 and LM-80 standards are lenient on LED. Lifetime is defined as expected hours before reaching *70%* output. CREE's extrapolated or accelerated testing data shows this to be around 50,000 hours. So, CREE forecasts that by the time it sees 50,000 hours of use, it will be down to 55.3 lumens/W. :001_huh:

Even F40T12 cool white maintained 90% after 10,000 hours and that is based on data from almost *40 years ago* from 1972 IES 5th edition handbook . 

Modern linear fluorescent lamps including T5 & T8 in normal output is within a single digit percentage over lifetime. The long life versions are rated to 40,000 hours IS/46,000 hrs PRS at 12 hour cycle. 



> The 2x2 T8 luminaire tested at the same time by the DOE had an efficacy of between 44-49 lm/w with a CRI of 81-86.


The CALiPER is a program for solid state lighting and fluorescent system are mentioned for benchmark only. How many 2x2 T8 luminaires are out there and how many did DOE test? 



CALiPER page said:


> *Does CALiPER do benchmark testing?*
> 
> Yes, the selection of products is designed to provide benchmarking data with respect to other light source technologies. In some cases, *"typical" fixtures* and lamps using incandescent or fluorescent sources are purchased and tested for luminaire performance to provide benchmarking examples. When possible, to enable a direct comparison between different light sources, one product is purchased and tested in both an LED version and a halogen version or CFL version of the same luminaire.





> Even if they used the worst T8 lamps in the report the best T8 lamps won't get it anywhere close to 79 lm/w.


No, not in that fixture. The site says "typical" fixtures are used for benchmark, not the best available. "typical" vs "best". Seems fair, huh? 

To have a good luminaire system efficacy, the fixture must have a good efficiency in addition to lamp-ballast system having a good efficacy. 



> So, no, the CREE is not on par or slightly below the best T8 system when considering all the way through to 2x2 "luminaire system efficacy", it is substantially better.


The CREE is substantially better compared to the luminaire chosen for testing, not against the *best* 2x2 fluorescent based luminaire available on market. 



> The CREE is over $500, but I already stated that the price doesn't make sense yet. The discussion was on efficacy and whether LED lighting would take over general lighting, eventually.


Sure, when they can match the best available fluorescent system in lifetime efficacy, life and cost. This would require them to have comparable initial efficacy and maintain 90% at 50,000 hours, as opposed to 70%. The 70% is basically a handicap setting for LEDs.

T5 non-HO
life 3hr/start 25000hrs, 12hr/start 35000 hrs (PRS)
96% @ 12,500 hrs 95% at 35,000 hrs 

T8 XLL 
life 3 hr/start 40000hr, 12hr/start 46000 hrs (PRS) (+60% and 31% resoectively) 
95% 20,000 hrs, 94% at 46,000 hrs and for those that live to 50,000 hours, forcast is 93.x % 

CREE lighting
life 50000 hrs useful to 70%
output at 50000hrs of use estimated at 70%.


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## Lighting Retro (Aug 1, 2009)

I have to admit I quit reading the long responses. But if I may, I can throw out my thoughts on why we don't spec out T5 unless it is HO for High Bay applications. T5 does have the higher efficacy (Lumens per watt-which is what get the utility companies happy). However, not by a ton. We have to compare this in the real world with costs. 

T5 lamps often cost double the cost of T8 lamps, and the ballasts are also significantly higher. Not uncommon to see a 50% difference in price there. T8 lamps are available in 28W or 25W if you just have to have a lower wattage lamp. You can retrofit an existing T12 fixture using just T8 lamps, whereas T5 requires a different fixture length, new sockets, etc (thus the reason for the adaptor) 

Like LED, overall we have not found there to be a legitimate business case for a T5 retrofit for T12 or T8 linear fluorescent fixtures. T8 offers a much better bang for the buck for performance that is not that far apart from standard wattage T5 performance. HO is another story. 

In short, don't waste your money on this product.


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## FutureLED (May 15, 2010)

Lighting Retro said:


> I have to admit I quit reading the long responses. But if I may, I can throw out my thoughts on why we don't spec out T5 unless it is HO for High Bay applications. T5 does have the higher efficacy (Lumens per watt-which is what get the utility companies happy). However, not by a ton. We have to compare this in the real world with costs..


From a technology standpoint my assertion has been that T5 has better efficacy than T8, and thus from an energy savings perspective is the better solution, just as T8 was compared to T12 when T8 first started gaining traction. I believe we are in agreement here.



Lighting Retro said:


> T5 lamps often cost double the cost of T8 lamps, and the ballasts are also significantly higher. Not uncommon to see a 50% difference in price there. T8 lamps are available in 28W or 25W if you just have to have a lower wattage lamp. You can retrofit an existing T12 fixture using just T8 lamps, whereas T5 requires a different fixture length, new sockets, etc (thus the reason for the adaptor)


The only downside, currently, with going to T5 is cost. I believe that is the assertion you are making. The tooling used to make T8 lamps is similar to T5, there isn't any more time per lamp used in manufacture or any special exotic materials. Thus, using much less material in manufacture and fitting 2.6x the amount of lamps in a shipping container clearly would indicate T5 has a much better ability to be lower cost than T8 when they are made in equivalent volume. We are already seeing this in Asia where a T5 lamp costs less than a T8 lamp.

In regards to the ballast, it is also a volume game. There is no special technology in a T5 ballast as compared to a T8 ballast. While T5 was designed to be used with program start ballasts, which increases the cost, there are instant start ballasts out there for T5, such as the ones from Fulham, which are the same cost whether for T8 or T5.



Lighting Retro said:


> Like LED, overall we have not found there to be a legitimate business case for a T5 retrofit for T12 or T8 linear fluorescent fixtures. T8 offers a much better bang for the buck for performance that is not that far apart from standard wattage T5 performance. HO is another story.
> 
> In short, don't waste your money on this product.


The question to you would be, if pricing were around the same price, would T5 appeal to you more? Further, when volume pushes price down, and T5 can actually cost less than T8, what would be your opinion?


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## Lighting Retro (Aug 1, 2009)

The name of our game is energy efficiency gains, so I evaluate technology first and foremost on that. Next comes availability of replacement material, warranty, application, performance, etc, etc. 

If T5 was the same cost as T8, and I could get the same reliability, it would be more attractive since you are squeezing more performance out of the product at a lower wattage. If I can get 3100 lumens out of a 25W T5, but it takes a 32W Hi Lumen T8 to get those lumens, that 7 watts could mean a huge competitive advantage and a stronger payback period. I'd have to pitch it if it was the best option for the customer. 

That being said, I can't see a device where each lamp has its own reflector being better than just buying a new fixture. Those parts are not easy to get if they go bad, and I don't think they will catch on due to the sizable price difference vs T8. You'd be better off using T55 lamps (T5 width, but T8 length) but I only know one supplier who carries those. If T5 ends up competing with T8 on price, I'm sure they will come up with a better solution than this to get it implemented.


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## garfield (Jul 30, 2009)

*Wow*

This is making for a long read but an interesting one. Thanks to all who posted!


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## TOOL_5150 (Aug 27, 2007)

WTF is all this... I didnt know there was that much to talk about luminaries and lamps.

~Matt


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## FutureLED (May 15, 2010)

Lighting Retro said:


> The name of our game is energy efficiency gains, so I evaluate technology first and foremost on that. Next comes availability of replacement material, warranty, application, performance, etc, etc.
> 
> If T5 was the same cost as T8, and I could get the same reliability, it would be more attractive since you are squeezing more performance out of the product at a lower wattage. If I can get 3100 lumens out of a 25W T5, but it takes a 32W Hi Lumen T8 to get those lumens, that 7 watts could mean a huge competitive advantage and a stronger payback period. I'd have to pitch it if it was the best option for the customer.
> 
> That being said, I can't see a device where each lamp has its own reflector being better than just buying a new fixture. Those parts are not easy to get if they go bad, and I don't think they will catch on due to the sizable price difference vs T8. You'd be better off using T55 lamps (T5 width, but T8 length) but I only know one supplier who carries those. If T5 ends up competing with T8 on price, I'm sure they will come up with a better solution than this to get it implemented.


I agree that these all-in-one "adapters", which are available from several companies, are not the ideal solution.

The spec sheet the OP posted shows two different products from that company, the second one appears to be a more standard implementation where you get a T5 ballast that gets installed in the fixture and have tombstone adapters that enable the fixture to accept T5 lamps. That, to me, seems like a much more natural and obvious method to retrofit an existing fixture to T5, you use the reflective properties of the original fixture (don't change the light output pattern), share the ballast waste among several lamps, and the fixture looks standard to maintenance personnel.

As I have stated several times my main interest here is in the technology. I don't own any company's retrofit kits so I can't comment on how well they do or don't work. However, I do believe that retrofit of an existing fixture to T5 can be done correctly, and will become a reality when the pricing makes sense.

Does anybody know how much any of the current retrofit options cost?

Interesting about the T55 lamps. Can you point me in the direction of where these are available?


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## Lighting Retro (Aug 1, 2009)

www.fleco.com carries them. They actually run off of a T8 ballast. This *link* shows a pic of it in an old catalog. I don't think they sell many of them. It was originally pitched to me as a way to guarantee service since no one else would know where to find them. True, but I want customers to come back to us because they want to, not because they have to.

Pricing on retrofit options varies widely depending on fixture type and solution, quality of material, and quantity you purchase. That's a loaded question. However, when I researched the option posted here compared to other kits, this one did not make financial sense. The only people buying this are the ones who don't know about other kits in my humble opinion.


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## FutureLED (May 15, 2010)

Thanks for the info. Seems intriguing, 30W and 3,500 lumens? That is 116 lumens per watt if it is to be believed.

Do you mind expanding more on your other comments? What other kits are available and what pricing were you quoted on the various options?


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## Lighting Retro (Aug 1, 2009)

From what I saw on some sample aged 6 Lamp high bay fixtures, it appears lumen depreciation might not be in line with current high end T8 standards. I have been reluctant to try them, as I know they are imports.


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## Electric_Light (Apr 6, 2010)

Lighting Retro said:


> From what I saw on some sample aged 6 Lamp high bay fixtures, it appears *lumen appreciation *might not be in line with current high end T8 standards. I have been reluctant to try them, as I know they are imports.


I'm sure you meant depreciation :whistling2:

The efficacy legislation is tightening up in 2012. None of the major manufacturers have come up with such a thing as 3,500 lumen 30W 48" lamp. 

That lamp is probably not ANSI listed and T8 ballasts are not designed to operate them. Ballast manufacturers prefer that you use their partner (i.e. Advance/Philips, Sylvania/Sylvania, GE/GE combo) but any listed lamp is allowed if they're ANSI listed. 

Ballasts that get fried from misapplication is obviously not covered by warranty. 

Ballasts are also UL listed on conditions that it is used for its intended purpose, not hooking up whatever you can manage to cram into the socket. 

So, using ghetto crap like that voids warranty and UL listing and perhaps not even comply with code, which most likely disqualify you from getting government and utility rebates. 

3100 lumen is about as high as it goes for 32W F32T8 lamps. Detailed specs are given for Sylvania at least...

http://assets.sylvania.com/assets/Documents/FL038R1.e5960706-ef72-4c26-9161-633f817703b0.pdf


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## Lighting Retro (Aug 1, 2009)

Yeah, I agree, but WHEN we get product with lumen appreciation, then we're going somewhere lol.


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## Electric_Light (Apr 6, 2010)

Ask the manufacturer/vendor what the lumen specs are supposed to be when it is operated on a 0.265A ANSI reference ballast and ask them to foot the lab test bill if the result comes back short of their claims. I'd be surprised if they say yes since integrating sphere tests are not cheap.


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## Lighting Retro (Aug 1, 2009)

Electric_Light said:


> Ask the manufacturer/vendor what the lumen specs are supposed to be when it is operated on a 0.265A ANSI reference ballast and ask them to foot the lab test bill if the result comes back short of their claims. I'd be surprised if they say yes since integrating sphere tests are not cheap.


Not sure who manufactures the lamps, but our preferred fixture manufacturer is a distributor. They carry domestic and import and have been the only ones to show us them. They are designed to run off of T8 ballasts, but we really don't have interest in them. I would think that T5 manufactures would have done this already though....make T5 in T8 length. Would negate the need for kits like described here. They'd also have a larger potential market.


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## Electric_Light (Apr 6, 2010)

Lighting Retro said:


> make T5 in T8 length. Would negate the need for kits like described here. They'd also have a larger potential market.


It really doesn't work that way. Ballasts are designed to be a constant current power source and you can't just make the lamps to operate at whatever current you want at whatever voltage.

It would actually be a worse idea than the kit. The kit,though may not provide any merit, does not use the existing ballast and only use the existing sockets as a 120v/277v "outlet" and uses a ballast intended for T5 lamp. The kit is more or less like an older CFL socket adapter with a lamp socket.


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## Lighting Retro (Aug 1, 2009)

what I'm saying is that a standard retrofit solution of lamp/ballast/reflector kit with new tombstones would sell better than this product if T5 lamps were the same length as T8. I can't think of a logical reason why they can't make T5's the same length as T8's even if they just use spacer material on the lamp ends. All T5 would be fine with me if it was competitive. Sorry I did not get my original point across.


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## Electric_Light (Apr 6, 2010)

Lighting Retro said:


> what I'm saying is that a standard retrofit solution of lamp/ballast/reflector kit with new tombstones would sell better than this product if T5 lamps were the same length as T8. I can't think of a logical reason why they can't make T5's the same length as T8's even if they just use spacer material on the lamp ends. All T5 would be fine with me if it was competitive. Sorry I did not get my original point across.


I have no idea, although they can always make long nose retrofit sockets. 
Single pin 4' slimline lamps aren't quite the same length as 4' bi-pin either.


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## Electric_Light (Apr 6, 2010)

FutureLED said:


> From a technology standpoint my assertion has been that T5 has better efficacy than T8, and thus from an energy savings perspective is the better solution, just as T8 was compared to T12 when T8 first started gaining traction. I believe we are in agreement here.


You're still skeptical about 10% efficacy gain lamps get on high frequency when compared to 60Hz, despite the fact this is something published in multiple editions of IES Lighting Handbook and many articles published on IEEE. 

T5 vs T8 is different from T8 vs T12 for the reason mentioned above. ANSI have traditionally assigned efficacy measurement procedures using line frequency. It wasn't until T5s came out that measurement based on HF was adopted.

F40T12s been around since 1960s and F32T8s since 1982. Back then, magnetic ballasts dominated and measurement standards were designed around them. When F32T8s came out, they were used with magnetic ballasts. 

When T5s came out, electronic ballasts were already in wide use and T5s were designed around them and magnetic ballasts for T5s were never put on market. 

This 10% difference caused by standards difference is huge. If you take it away, it makes the difference between T5 and T8 so small as you already know. 

There is an efficiency difference between the earliest T8 electronic ballasts and the newest. Obviously a T5 system utilizing the cutting edge electronics will compare favorably against the old T8 ballasts. This has nothing to do with "T5 technology" you like to sing. 



> The only downside, currently, with going to T5 is cost.


Given the same output and length T5s have higher surface brightness, which creates glare issues that must be addressed in direct lighting applications. The phosphor is also exposed to higher UV intensity(watts of UV output to inner surface area ratio), so if both lamps used the same phosphor, T5s are more susceptible to accelerated phosphor decay, which translates to lumen depreciation. 

There is a clear advantage with using rare earth phosphors instead of halophosphors. UV intensity is higher in T8 lamps and for this reason, T8 lamps are made with rare earth phosphors. 
1/2 x 1/2 = 1/4 
and 1/4 x 1/2 = 1/8
and 1/16 is still half of one eighth, but clearly, you're seeing a diminishing return. 



> I believe that is the assertion you are making. The tooling used to make T8 lamps is similar to T5, there isn't any more time per lamp used in manufacture or any special exotic materials.


Hence, it really isn't "T5 technology" as much as it is using a different diameter tube. Same with T5 programmed start ballasts. It's no different from T8 ones, except for having different specs.


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## Electric_Light (Apr 6, 2010)

When I searched T5 retrofit adapter, a bunch came up, mostly based on marketing. Found this Made in China stuff and many marketed by US companies have the same instructions "bypass rapid start ballast".

http://www.helico.com.cn/Uploads/2009-9-8-104048.PDF


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## Electric_Light (Apr 6, 2010)

FutureLED said:


> All you can do is argue semantics now? In regards to Xenon fill, once all patents are filed the pertinent information will come out.


I'm not sure if this is the one you're implying, but I did find a xenon fill patent application involving T5 lamps. Filed on behalf of General Electric Company.
Publication 20080278073 at US Patents office. It's showing final rejection notice was mailed out on May 14th, 2010.


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## Electric_Light (Apr 6, 2010)

FutureLED said:


> http://genet.gelighting.com/LightProducts/images/t04/0000000/r00357v-1.pdf
> 
> Take note how they state a 32W T8 has 2,800 initial lumens and compares that to 3,050 initial lumens of T5 without any of your correction factors. They even go further to state ballast-lamp lumens for T8 without any correction factors. This is the same you are accusing the company you call a "gimmick" of. I trust you are equitable in your criticisms and will refer to GE in the future as "that gimmick company" as well.


I assume you don't have access to IES Handbook, although this is something hosted on Advance's website. Have a look at page 8.
http://www.advance.philips.com/documents/uploads/literature/RT-8010-R03_ABC.pdf

To repeat myself, T5 lamps were never meant to be operated at 50/60Hz, and they were rated at 25KHz(IEC standards), so they already reap the benefit.

Just to see this yourself, pick a T5 lamp, calculate catalog lm/W, then pick a ballast, and calculate system lm/W. You'll see that the difference is much greater for T5, because published lamp lumens already assumes HF operation, so ballast loss directly shows up in calculated efficacy. 

For T8, you can have system efficacy that matches or exceeds lamp's published lm/W(based on 50/60Hz) due to efficacy gain from HF operation.


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