Light ???

then if it cant produce better than the 600 watt hps ill put a 400 watt hps in the hps room see if it can output that...but i really dont want to spend months and room wasted just to lose needed yields..so i hope the led you recomend can do just as well if not better than my 600 hps...

churchhaze said:

Don't even bother trying to find a decent LED light for a 4x4 for under 600 dollars. It does not exist. Just stick with HPS.

It's not the style "cob" that makes it better, it's the specifics.

Click to expand...

ok, at what price does it exist? what brand, what style, cob, reg? also will it actually save on electric? ive noticed the ones i see that say they cover a 4x4 area are at least 600 watts,,,,so how is that saving electric?? what is better a cob or reg and why?

TheChemist77 said:

ok, at what price does it exist? what brand, what style, cob, reg? also will it actually save on electric? ive noticed the ones i see that say they cover a 4x4 area are at least 600 watts,,,,so how is that saving electric?? what is better a cob or reg and why?

Click to expand...

$2499 will do http://www.apachetechinc.com/white-red/25-at600.html

I'm serious, don't bother with those chinese epistar led panels. I can only vouch for vero 18 and vero 29 3000k 80cri whites, which produce exactly like HPS did for me in the past only with less power. The cxb just came out a week ago, and is even more efficient than vero and cxa.

You're right to be skeptical. Almost everyone insisting they're saving power and producing less heat are actually fooling themselves.

HPS IS BETTER than almost all leds you see people using.

Please don't buy some "affordable" leds and compare them to HPS just to be disappointed. Everyone knows you will get shit results and HPS will win.

DIY white cobs blows everything else out of the water.

TheChemist77 said:

ok, at what price does it exist? what brand, what style, cob, reg? also will it actually save on electric? ive noticed the ones i see that say they cover a 4x4 area are at least 600 watts,,,,so how is that saving electric?? what is better a cob or reg and why?

Click to expand...

churchhaze said:

I'm serious, don't bother with those chinese epistar led panels. I can only vouch for vero 18 and vero 29 3000k 80cri whites, which produce exactly like HPS did for me in the past only with less power. The cxb just came out a week ago, and is even more efficient than vero and cxa.

You're right to be skeptical. Almost everyone insisting they're saving power and producing less heat are actually fooling themselves.

HPS IS BETTER than almost all leds you see people using.

Please don't buy some "affordable" leds and compare them to HPS just to be disappointed. Everyone knows you will get shit results and HPS will win.

DIY white cobs blows everything else out of the water.

Click to expand...

Tell me more about this DIY white COB. I'm thinking about a particular application... that certainly doesn't exist in the marketplace yet.

According to the datasheet, the efficiency of a cxb2530 3000k warm white u2 bin at 500mA is 49.1%. That is the top model that was released recently, and will handle a 2'x4' tent with 193W of electric power and a 94% efficient driver.

By contrast, the vero 18 at 700mA is about 39.8% efficient, and HPS is 35% efficient. Area51 is 34% efficient.

http://www.cree.com/~/media/Files/Cree/LED Components and Modules/XLamp/Data and Binning/ds CXB2530.pdf

The datasheet does not outright tell you the efficiency, but we have a few people who digitize the spectrum charts and do the calculus needed to calculate LER. With LER, lumens can be converted to radiant watts to calculate efficiency. That's how we come up with the efficiency numbers.

TheChemist77 said:

ok, at what price does it exist? what brand, what style, cob, reg? also will it actually save on electric? ive noticed the ones i see that say they cover a 4x4 area are at least 600 watts,,,,so how is that saving electric?? what is better a cob or reg and why?

Click to expand...

churchhaze said:

According to the datasheet, the efficiency of a cxa2530 3000k warm white u2 bin at 500mA is 49.1%. That is the top model that was released recently, and will handle a 2'x4' tent with 193W of electric power and a 94% efficient driver.

By contrast, the vero 18 at 700mA is about 39.8% efficient, and HPS is 35% efficient. Area51 is 34% efficient.

Click to expand...

Cost per each? How many are required to provide equal light pressure (not 'equivalent results'- as we all know, this is hype 'statistic' based on guesswork) to a new 600W HPS lamp?

How much does the driver or controller cost and how many will it run?

What else is needed to make them operate properly in a grow room?

I just don't know much about the current state of the LED art.

ttystikk said:

Cost per each? How many are required to provide equal light pressure (not 'equivalent results'- as we all know, this is hype 'statistic' based on guesswork) to a new 600W HPS lamp?

How much does the driver or controller cost and how many will it run?

What else is needed to make them operate properly in a grow room?

I just don't know much about the current state of the LED art.

Click to expand...

http://www.digikey.com/product-search/en?KeyWords=CXB2530-0000-000N0HU230G&WT.z_header=search_go

Crazy Expensive.

To operate properly, you need big ass custom heat sinks, and an efficient constant current driver. You will have to learn to drill holes in aluminum and tap threads. Etc. It's really not something you can jump into without doing a lot of homework first.

30-35W/sqft was a good amount with my vero 18 at 700mA setup. It's too early to say definitively since it just came out, but I'm almost positive this new cxb top bin underdriven build will yield well with only 25-30W/sqft. I'll know soon enough, because its almost done and time to hang up!

This is what the vero 18 3500k 80cri light looks like. About 40% efficient. 80watts each. All 3 panels together go in a 4'x2' tent as well. The cxb panels are meant for a new tent that will compete side by side. Titled, the "80W UFO Killer"

churchhaze said:

The datasheet does not outright tell you the efficiency, but we have a few people who digitize the spectrum charts and do the calculus needed to calculate LER. With LER, lumens can be converted to radiant watts to calculate efficiency. That's how we come up with the efficiency numbers.

Click to expand...

With "a few people" are you referring to the led fans in the led forum here? So the efficiency numbers you mention is not even electrical efficiency but numbers the led fans came up with comparing to some streetlight hps?

The lumen per watt efficiency of a good 600watt hps is 10% higher than that new cree you mentioned. Misleading yes, just like 49 vs 35% not resulting in that nearly 50% yield difference or electricity savings.

First of all, I am running that LED at 500mA, not 800mA like the test current.

Second, there is no such thing as luminous efficiency. Efficiency is always W/W. There is no type of efficiency that has units. Efficiency is always unitless. Lumens/watt is efficacy, not efficiency, and there are 2 types of luminous efficacy so it's even more confusing. It could mean the lumens per electric watt, or it could be lumens per watt of radiant power. In this case, it means lumens per electric watt input.

Because the spectrum of HPS is different than the spectrum of the 3000k 80cri white leds, lumen alone can not be used to determine radiant power output. You need to know for that given spectrum how many lumens there are per radiant watt so you can convert lumens to radiant watts for that given spectrum.

The calculus these LED fans are doing (independent people doing the calculations) is digitizing the spectrum charts and using the relative phoptic luminous efficacy curve to find the actual radiant output in watts rather than lumens. There have been conflicting LER values by different "fans", but for the most part they've been very close.




That means that light sources with lots of green and yellow will have higher lumen count for the same radiant power, the same lumens of blue will be more radiant power than the same lumens of yellow according to those charts.

Third, I'm running at a considerably lower case temperature than the listed test temperature. Cree has pretty high test temperatures, making their specs look low.

And I'll show you results in grams soon enough.

Sativied said:

With "a few people" are you referring to the led fans in the led forum here? So the efficiency numbers you mention is not even electrical efficiency but numbers the led fans came up with comparing to some streetlight hps?

The lumen per watt efficiency of a good 600watt hps is 10% higher than that new cree you mentioned. Misleading yes, just like 49 vs 35% not resulting in that nearly 50% yield difference or electricity savings.

Click to expand...

churchhaze said:

http://www.digikey.com/product-search/en?KeyWords=CXB2530-0000-000N0HU230G&WT.z_header=search_go

Crazy Expensive.

To operate properly, you need big ass custom heat sinks, and an efficient constant current driver. You will have to learn to drill holes in aluminum and tap threads. Etc. It's really not something you can jump into without doing a lot of homework first.

30-35W/sqft was a good amount with my vero 18 at 700mA setup. It's too early to say definitively since it just came out, but I'm almost positive this new cxb top bin underdriven build will yield well with only 25-30W/sqft. I'll know soon enough, because its almost done and time to hang up!

Click to expand...

Please invite me to the thread where you build and test it.

I'm running 20 W/ft² using HPS right now, with good results. I'm betting this would be a marked improvement.

http://rollitup.org/t/diy-cxb2530-3000k-80cri-u2-bin-vero-killers.862298/

There won't be a journal, just an "instructional", but I do give out plant pictures once in a while.

ttystikk said:

Please invite me to the thread where you build and test it.

I'm running 20 W/ft² using HPS right now, with good results. I'm betting this would be a marked improvement.

Click to expand...

Sativied said:

With "a few people" are you referring to the led fans in the led forum here? So the efficiency numbers you mention is not even electrical efficiency but numbers the led fans came up with comparing to some streetlight hps?

The lumen per watt efficiency of a good 600watt hps is 10% higher than that new cree you mentioned. Misleading yes, just like 49 vs 35% not resulting in that nearly 50% yield difference or electricity savings.

Click to expand...

After a nights worth of work, here's 22 drilled and tapped holes, etc. I bet it will do terrible flowering because it doesn't have a pink tinge to it!

193W of electric power dissipation, about 95W PAR according to the LED monkeys.



Hey @Sativied, I promise you it's 110% efficient!!

Too much good info in here. This should be a sticky.

Sativied said:

just like 49 vs 35% not resulting in that nearly 50% yield difference or electricity savings.

Click to expand...

How can you possibly know whether it results in more yield yet? It (cxb) just came out about a week ago, and I'm the first one who's posted a build/design using it. We're still waiting for more people to have their parts arrive and post pictures of their cxb builds.

Up until now, everyone's been praising cxa DIY builds as being top of the line. Cxb is a drop in replacement for cxa. There are no results yet, but considering cxb has flux bins a step up higher than cxa, I would expect even better yield.

churchhaze said:

How can you possibly know whether it results in more yield yet? It (cxb) just came out about a week ago, and I'm the first one who's posted a build/design using it. We're still waiting for more people to have their parts arrive and post pictures of their cxb builds.

Up until now, everyone's been praising cxa DIY builds as being top of the line. Cxb is a drop in replacement for cxa. There are no results yet, but considering cxb has flux bins a step up higher than cxa, I would expect even better yield.

Click to expand...

What's a flux bin?

ttystikk said:

What's a flux bin?

Click to expand...

For white leds, flux bin is a code that corresponds with an absolute lumen rating at test current and temperature. Each cob size, color temperature and cri has a different set of flux bins. The top bin is the most desirable.

It's a result of the manufacturing process being imperfect. They sort the best performers out and put them in higher flux bins, and the worst ones go in lower flux bins.

Page 7 of the datasheet for this particular array shows what each flux bin represents. Page 4 shows the 3000k 80cri option. U2 is the highest bin for that option and means 3680-3955 lumens at test current and temperature..

http://www.cree.com/~/media/Files/Cree/LED Components and Modules/XLamp/Data and Binning/ds CXB2530.pdf

Since the flux bins are absolute, top bins on larger, and more blue arrays tend to have higher available flux bins.

churchhaze said:

How can you possibly know whether it results in more yield yet?

Click to expand...

I'm not the one pretending to know whether it will yield more and how much exactly, down to a %...

I said it won't line up with those skewed wall plug efficiency percentages you mention as if they are all what matters when comparing light sources, and not what you twist it in, again, whether it yields more or not. I assume it doe,s for the same reason I know it won't line up with those percentages, I'm realistic in addition to skeptical.

If that imaginary 35-49% translates to reality, 2015 will be the last year I grow on HPS...

Uncle Ben said:

None of the above.

The size of the lower buds is not related to light intensity. That is another forum myth. Read my thread Riddle linked you to.

Roots are a plant's foundation. Like I said, the more the effective root surface area the more potential yield or plant mass in general.

Ever planted a tall, leggy tomato plant (correctly)? Say it's 12" tall with long internodes. You dig a shallow trench, lay the entire trunk sans leaves in that trench, cover it up and within a day the plant will have straightened up and once established will grow like crazy.

Click to expand...

And people give me shit for putting three plants in ten gallon smart pots in a 4x4 tent