that is untrue because if it fails it becomes the same as one without fans, its not like it runs fans because its hotter but rather because it protects it from the number one cause of failure in electronics,overheating.also both ballast save electricity when u dim them, all dimmable ballast save electricity when dimmed, i have tested this with a meter.
Companies don't put extra stuff in - esp things like fans (that are another moving part that fail - most common failure in PCs) - if they don't need it - OR if they're putting it in for backup - in which case they push that redundancy hard in all their ads.
Read them both. From the manufacture site.
Quantum doesn't say "we put in a fan as backup but you don't really need it". They say "we have a fan to help cool it".
Lumatek says (paraphrasing) "with careful design we eliminated the need for a fan thus eliminating a failure point"
So Lumatek has specifically designed cooling - as well as most likely component sizing - to not need a fan to run properly. Quantum has not. And likely everything about the design is dependent on that (smaller MOSFETS, over or less-under driven components, etc).
So you can't just say Quantum with dead fan is just like a Lumatek that never came with one. Such a comparison is just too simplistic.
For another quote about "unsafe hz" that's also not founded in reality. Darn near every electronic power supply, embedded or not, that isn't some old huge wall-wart ,is a switcher, and they all run at very high frequency. 40-100khz. They do that because all of the circuitry is both more efficient and more compact at those frequencies. . On that same line, even car/electronics inverters go 12V -> 145V (usually) and then down convert to the target voltage. These (both, or all) are probably doing just that (common design) and then down converting to bulb voltage not 12V (and leaving it A/C not DC) So if you're worried about safety of switcher frequencies put a tin foil jacket on because you're surrounded by them
Which is better? I dunno. I just ordered a Lumatek 250 dimmable. Based on exactly this type of discussion - apparently better electronics design by my read of specs. And having often to fight fans in computers know they're a failure point (that type of fan is highly dependent on quality). On the other hand, I have a Vector car Inverter that has a fan. And at 10+ years, it's a noisy one for the first 10 minutes. And it needs to fan to run full load. But it's still OK.
There do also seem to be a lot of truly crappy clones. What's the quote? "Go ghetto and expect ghetto". But for Lumatek and Quantum: by my read and the fiercely loyal followers, both would probably serve you well. The Lumatek at least won't have a fan fail to shut it down (even if temporary may affect your grow). Just don't go ghetto.
I felt (from their docs) Lumatek spent more time and electronics on a better more reliable design. So I went that way.
I'll also note that PCHydro has Lumatek 250W dimmable for $90 which is an outstanding price.