Bridgelux leds

FiReBReTHa · Oct 4, 2011

definitely need fans, that U channel doesn't have much meat to it. For optimal spectrum you want the LED running at 74 degrees. (not possible without extensive active cooling) but that should be your guidelines. Doesn't make sense to me to make something for an 11 year life cycle and then come up short on protecting it with such thin thermal management.

Bernie · Oct 4, 2011

What sort of spacing are we talking about here? I keep looking at builds, but haven't noticed anyone saying how far they are spacing out the LEDs.

Also, would 90 3W LEDS be able to properly cover a 1776 square inches? Well, I guess "properly" is a relative term. The jist is, would 90 be more suitable for a 4' tank than a 6' tank?

I don't mind tacking on an extra 24 or 36 LEDs to the order, but I'd hate to go through the trouble of building it and then having to add more lights.

ronnie · Oct 4, 2011

On the light I built with 3" channel (that is running currently), I ran two rows of LEDs. They are spaced at 1.75" center to center going left to right and 1.5" center to center between the two rows.

I would definitely bump the 90 up a bit. Probably go with 36 more. You can always dim them more if you need to, but like you said, having to add more later would be a pain.

On my 120G (4x2x2), I am planning to run 77 whites and 52 blues (from FEDY). These will be on the 2" channel I linked above. Spread across thirteen pieces that are 18" long.

wld1783 · Oct 6, 2011

There are a lot of things to consider Spectrum and Thermal Management are KEY

The Bridglux does offer a good upfront spectrum but do not bin their LEDs or this information is less available than the Cree Bins. Cree has a founded reputation. Commercial fixtures who manufacture their own LEDs or at least those that say they do use the old advertising term same quality as "Cree"

Cree is very open on their claim of 50,000 hours and after that the LEDs will be at least 7o% of their original brightness...Will their be a slight spectrum shift at this time...Likely but to what extent still has to be proven in the field.

The claim of 50,000 hours is also based on proper thermal management. the LEDs must be kept cool we did an under water experment with a Cree XR-E and LED SEAL and the point source was so hot it boiled saltwater. This was evident on the star with micro bubbled directly behind the LED.

This also brings into the equation on which is better. The Thermal Transfer Properties of a Bridglux star or a Cree Star...There are many Cree Stars some like the indus can transfer heat 10-30% better than a generic or cheap star.

Personally like my Motorcycle I prefer to over do it with CC. A 50cc moped works but a 1200CC BMW works better. Yes the BMW costs more but will last longer and trust me a lot less embarrassing when people you know see you on one:wink:. Providing a quality extruded heatsink for your LEDs is cheap insurance over the long run. If your lighting a FOWLR Home Depot C Channel works fine but as soon as you start replacing MH Lights a well thought out thermal management plan is key. Some less expensive generic fixtures using Bridglux LEDs skimp on this as their vendor has claimed that the LEDs will fail if the fan is turned off...This will not happen under a quality thermal management design. Nor will it be an issue with a more efficient LED that produced less heat.

I personally do not own a thermal heat camera so the specifics of this are opinion and touch experience. I do own a PAR Meter and pay rising electrical bills so here is a rough cost benefit analysis of different LEDs. I was surprised by the results and all data was taken from online data sheets. To simplify it Regular aka common Cree XP-E were the baseline, the Bridglux were cheaper for 15 months, then more expensive. Premium Cree Bins had a longer payback but better spectrum and higher quality star were not considered. Surprisingly the most expensive LED the XM-L was the cheapest when driven at 2000mA and the most expensive when driven at 700mA. CBA was based solely on average online price and luminous out put compared to nation wide electrical rates.

The bottom line is if your dating LEDs and have a short term view the Bridglux works but dont do it in a common law state. For me I prefer the longer more reliable view.

Bill

ronnie · Oct 6, 2011

When I ran the numbers, my payback time was 9.2 years. That means it would take that long to realize a savings when buying bridgelux compared to Cree.

That was assuming that a Cree LED was 1.5 times better (from your number it looks like that is pretty close)

wld1783 · Oct 6, 2011

Ronnie

Not sure how you ran the numbers but our analysis gave the BirdgLux a 15 month advantage after that they were more expensive...

If one was looking out only for short term results the BridgLux win.

That said the Premium Cree currently carry a 10-30% Premium in price based on output and demand...You have to factor in that more light with same current is more thermally efficient. We did not consider this in our CBA.

Thier price is also dropping like any other electronic product...Hopefully as fast as Al Gores pants do during a hotel message...:neutral:

Bill

Onedesign1 · Oct 7, 2011

I'm one of those 'other guys' on the other forum. To get the same amount of light i had to use 2X as many FEDYs as Crees. in fact just do the math on lumen output.

The FEDYs/bridgelux work fine...however they are terribly inefficient and produce an incredible amount of heat if you drive them near 700ma...in fact I had fans go out in a hood and the full blown extruded heatsink was so hot it scared me. I don't have to run fans on my Cree fixture over my 120g but I do and its cold to the touch. As for the Chinese drivers....I wouldn't use them....alot of flaky results. As you can see in the FEDY thread on the other forum even the OP is using MW now.

All that being said I am running FEDY 18000ks with CREE XPE RBs on my 29g cube and over my frag tank (hey I had to buy 100 of them). 2 of the 18000k to 1 Cree RB. In total I'm running 40 FEDYs and 20 Crees over a 36x18x18. works fine, runs hot as a pistol if the fans are not on. have lost about half a dozen individual LEDs in 6 months. I have spares so no big deal. When I run out of spares I'm scrapping them and going back to Cree. It was more an experiment for me.

Over my 4x2x2 120g I'm running 24 XPG CW Crees and 44 XPE RBs plus a few greens and reds. Bottom line the FEDYs don't compare to Crees. By all means use them if you like them...when they blow replace them. I urge you to use better drivers though...those things scare me.