[Electric_Light]

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.

 

[FutureLED]

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.

 

[FutureLED]

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.

 

[Electric_Light]

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:

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)

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.

 

[Electric_Light]

merge w/ below

 

[Electric_Light]

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?

 

[FutureLED]

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.

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

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.

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.

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.

 

[Electric_Light]

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.

 

[FutureLED]

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.

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.

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.

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.

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.

"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".

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

You absolutely did, multiple times.

 

[Electric_Light]

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

 

[MDShunk]

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

 

[Bob Badger]

This is awesome.:thumbsup:

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

 

[NolaTigaBait]

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....

 

[FutureLED]

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.

 

[Electric_Light]

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.

 

[FutureLED]

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.

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 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.

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".

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.

 

[Electric_Light]

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.

 

[FutureLED]

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.

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.

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.

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.

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.

 

[Electric_Light]

:ugh:
stop calling lamps "bulbs"

 

[Electric_Light]

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.