BE WARE !Fuorescent tubes underperform if cooled (fan pointed at it, for example)

I have experienced this before reading anything about it, and feel it MUST be mentioned, especially in stickied threads about CFLs.

If the tubes get colder ( 10-15°C?) than they would be normally, they dim, a lot...
I've noticed this after pointing a fan between them and my plants, and within short time they went from shining bright to almost grey.
Applies to CFLs too.
It is also not much of an issue with newer, amalgam lamps.

If anyone with stickied threads regarding tubes and CFLs could incorporate this little information into your thread, It would be great to see it mentioned.

BEWARE !Fluorescent tubes overperform if you just doubled up the ballast,

get an extra 55% more light out of your T5 fixture or CFL, simply by doubling the ballast capacity ....true! Although a lot of fiddling and some soldering is involved, to many it's worth it, but me ...? I just buy more lights ....lol, and yeah don't have your fan of any phosphorous tube ...is dumb

does this apply with normal CFL's ?

Dude you must have some ancient flouros...I have a set of T5s for sprouts and a 20" box fan blowing on it and their bright as fuck...they work in temps of 20F and above, I'll give ya that but to dim the light that much it must be an old ballast and tubes...

Riknstein.
As it seems, it only affect lamps containing mercury, and amalgam technology has bypassed this issue. According to this, you are partly right.

FYI, I have this combination http://www.osram.com/media/resource/hires/336429/family-data-sheet-dulux-l-lumilux-de-lux.pdf

I didn't want to post links, but this really is just a short read and 2 diagrams you should look at: http://www.lrc.rpi.edu/programs/nlpip/lightinganswers/hwcfl/hwcfl-thermal-performance1.asp

I understand they have a min. working temperature, but if it exceeds it and starts working, it will still heat up by itself. I had this problem when I had a 12v fan spaced tightly between them and my plants, and it got tilted upwards at the tubes.

Also, thank you vostok for NOT contributing, at least I know I'm an idiot...

vostok said:

BEWARE !Fluorescent tubes overperform if you just doubled up the ballast,

get an extra 55% more light out of your T5 fixture or CFL, simply by doubling the ballast capacity ....true! Although a lot of fiddling and some soldering is involved, to many it's worth it, but me ...? I just buy more lights ....lol, and yeah don't have your fan of any phosphorous tube ...is dumb

Click to expand...

And why would the idea of a fan blowing at the plants with the tubes close be DUMB? If they can operate without that much loss in light output at a 10°C less temperature, you can just grow your plants around them touching everywhere.

Does any of this not concern anybody?

Just because I have not read about this anywhere in the forum, like it's common knowledge...

Ive never had that problem and have done 17 grows with fans pointing on lights

Maybe you don't even know... just because you know... you've always been doing it

But seriously, not all kinds of flouro has this drawback.

thats why the epa banned production of flourescents in the U.S. many many decades ago. Actually J.P morgan paid to have them banned in the in the 1890's before the epa was around.

Any light with mercury phosphors can be poisonous if broken. Cfl's are bad in general due to the amount of uv-c rays they put out.

Hyroot that wasn't quite relevant, but thanks for pointing it out. Be sure to contribute to the thread next time :/ no offense, really

On an average they may lose 10% percent output if out of optional temp range, which equals to 1600 lumen for 4x t5ho.
On the website of the fluoerescent tubes I'm using, 35°C tempreature is stated as optimal.

I am very displeased with their performance regarding temperature dependence, but it was about time to learn what "CONSTANT" tubes mean.
However, I still plan to use only fluorescent tubes to vegetate my plants.

PS: this drop in output also applies to "overheating".

See the difference? SEE?

The brighter is above my just-sprouted chile peppers, while the other (pale) is in my growbox.
You guessed right... The peppers' lights are at room ambient temperature, while in my grow box the temperature is raised by the lights.

Mercury amalgam floro (like induction flouro) still will loose output when not operating at full temp.

Care to share what you've experienced?
I don't understand why this hasn't been written about in so many threads, and I would thank you for your input.

Have a good day. (Night?) What time is it at you?


PS: You meant those that they brand "constant"?

my 4' 8 tube fixture gets hot as hell and i NEED the fan...temps rise above 40 if its not in there.
i was reading a few of the other comments and they seem to be right when they say its just bubs containing mercury.