• Here is a link to the full explanation: https://rollitup.org/t/welcome-back-did-you-try-turning-it-off-and-on-again.1104810/

Gavita double ended...

AquariusPanta

Well-Known Member
You smoke rocks don't you. It's only obvious the pic with the led was with someone who doesn't know how to grow and the T5 pic is a T lie. All I see is finished product not plants growing under so called lights.
Wait, aren't crystals considered rocks and can't THC come in the form of crystals?

Ok, slap the political correctness out of me :razz:.
 

dbkick

Well-Known Member
If I lived somewhere cold with cheap electric I'd buy a DE tomorrow to see what it can do

But otherwise it's not a practical option at all..
Fair and decent answer. There will be plenty of people to show you but it will always be a pissing match this led vrs the rest of the world lighting. Personally my fave right now is the sun systems lec 315 , 1.95 umole/s , 315 watts((included for PSU sake). The light is a monster for the wattage and the DE outdoes it at 2.1 umole/s per watt.
 

churchhaze

Well-Known Member
Assuming a luminous efficacy rating (LER) of ~328lumens/watt radiation. (good estimate for cxa/cxb 3000k 80cri spectrum):

The specs for cxb2530 3000k 80cri u2 bin show 133 lm/W at test current and case temperature (800mA and 85C). With LER of the spectrum taken into consideration, that 133lm translates into 133/328 = 0.405W of radiant power per watt of electric input power.

0.405W/1W = 40.5% efficiency

I am running them at 500mA rather than 800mA, and case temperature is kept lower, according to the datasheet, lm/W is more like 161lm/W, and efficiency is 49.1%
 
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churchhaze

Well-Known Member
I'm not sure what LER supra is using to calculate efficiency, but I'm sure it's not far from 328lm/W. The efficiency numbers look even better if you plug in a LER of 325lm/W obviously. Different people have calculated different LER for the cxa 3000k 80cri spectrum , but they've all been extremely close.
 
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PSUAGRO.

Well-Known Member
Why you led folks gotta be the way you are I have no fucking clue. This thread has truly lost something of the original post, that's disruptive and have at it,
So you don't think the DE's amp load/wattage draw is relative to this discussion?Especially considering the additional cooling needed in most situations.

We aren't even gonna talk about reflector losses and how those manufacturer#s aren't gonna play out with actual ppfd....
 

dbkick

Well-Known Member
So you don't think the DE's amp load/wattage draw is relative to this discussion?Especially considering the additional cooling needed in most situations.

We aren't even gonna talk about reflector losses and how those manufacturer#s aren't gonna play out with actual ppfd....
Since it's no more than the same lights some us have been using for decades now I don't see wattage a factor no.
I intend to use the sealed air cooled feature of the hood I bought so there will be an extra pane of glass but I really don't see that as a problem since it allows me to run co2. I'll take the glass out and run a 10000k mh for the last couple weeks anyway. If you're saying do I think there's been a improvement made to the old tried and true HID? Hell yes.
 

SupraSPL

Well-Known Member
@dbkick congrats on your lamp bro, it will grow some serious bud no doubt and on the cheap compared to LED, unless the HPS heat is limiting your yields and quality.

But as far as the old HPS vs LED goes...

160k+lumens, 2100 umol/s. cxb what?
The bulb in the Gavita, when brand new is capable of emitting 2.07umol/W and drops to 1.66umol/W after reflector losses.
The CXB2530 3K U2 at 500mA emits approx 2.39umol/W no reflector losses necessary in this setup
The CXB3590 3K CB will be floating around, at 700mA it emits 2.66umol/W, dropping to ~2.5umol/W after reflector/lens loss

To take that a step further, the LED umol is "better" because the SPD is much more spread out and the light can be spread much more evenly in the canopy. If you were so inclined you could scale that up to a much higher intensity than a 1000W HPS can. The HPS setup is going to create a lot more heat to get the same job done, not even taking into account the infrared beam that will boost canopy temps causing fluffier buds and reducing terpenes.

Philips 1000W DE bulb SPD with 820nm infrared heat spike (spectral data from growershouse) This SPD is generally the same for all the DE HPS bulbs
Philips DE spectrum.png
 
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SupraSPL

Well-Known Member
I'm not sure what LER supra is using to calculate efficiency, but I'm sure it's not far from 328lm/W. The efficiency numbers look even better if you plug in a LER of 325lm/W obviously. Different people have calculated different LER for the cxa 3000k 80cri spectrum , but they've all been extremely close.
I use 325 LER for the CXA 3K spectrum. That number came directly from Cree from their study of the CXA2540. The CXB 3K spectrum is very close so I used the same LER.
 
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