# 25W 'Shoplight' Tubes?



## MacGyver (Mar 13, 2006)

I found some of these recently, F48/25W/UTSL.
What is the advantage over something more mainstream, like 'regular' cool white F34CW/RS/WM tubes?
The 25W ones are same life, same CRI, lower lumens output according to the GE fluorescent PDF I have.
Is that it, just for any application where you may not want as much light as possible?
Seems I always want more so I'm curious :candle:
Thanks


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## winny (Mar 13, 2006)

I'm not sure what florescent tubes you are talking about, but in general, you sometimes want to over-render red (compared to standard florescent tubes or sometimes even compared to incans, especially when it comes to bread and flowers). The CRI-value won't tell if you over-render a certain color, you would need to look at the color vector diagram for that.
That could be a reason why it isn't as efficient as regular tubes.
Other explanations are what shorter tubes (less powerful) aren't as efficient or that your model just isn't a very efficient tube.

I hope that might have straighten out at least something for you.


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## jtr1962 (Mar 14, 2006)

There is no advantage to them. All 25 watt shoplight tubes are is an "energy saving" version of standard 40 watt tubes with proportionally less output. I looked at the specs for these and they had 1860 initial lumens (74.4 lm/W) and a CRI of only 60. In short, they had no efficiency advantage over better tubes and the color rendering is absolutely horrible. Honestly, given how cheap tri-phosphor tubes with decent color rendering and better efficiency are these days, I really don't know why tubes like this are even made any more. When running on a magnetic ballast between the flicker and poor color they're a perfect recipe for migraines, and one of the reasons people say they hate fluorescent lighting.

My advice-stay away from them. They won't work in most standard 4-foot tube fixtures anyway. Get a decent T8 electronically ballasted fixture and a set of decent tubes. SPX phosphor tubes have a CRI of 86 and are fairly cheap, plus available in all the common color temperatures (3000K, 3500K, 4100K, 5000K, 6500K). If you want to spend somewhat more, you can get full-spectrum 5000K tubes with a CRI of 91 to 93.


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## MacGyver (Mar 14, 2006)

jtr1962, I was thinking along those lines, thank you for confirming my suspicions, and the detailed explanation :thumbsup:
winny, you probably don't have the exact same tubes available in Europe then, my numbers above are for standard 48" GE ones here.
Of course, as jtr1962's pointed out, you're not missing anything 

Well, as indifferent as I've been to electronic ballasted linear T8 tubes...mebbe it's time to join this century & try some out...


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## Handlobraesing (Mar 23, 2006)

The 25W 48" lamp is the same as a regular 40 watt. They market it as 25W for residential use with low-output shop light ballast, as to make it legal.

The F40T12 Cool White 40W type lamp intended for use on full output, commercial rated, 40W ballast is outlawed under EPACT.


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