Gavita's are they really worth the price ??

sixstring2112 said:
mongo your limited build pics look good and im def gunna go see if i can find some flat aluminum now lol.also if you plan to run 750w of cob next to a gavita 750 your going to be amazed at the cobs lol.
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Right? Im with you on that. Looks smooth and alot less drilling lol

coughphee.connoiseur said:
Well damn ...... Men lie women lie but numbers don't.
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Exactly. Thats the only reason I got into COBS... The numbers dont lie. Run them at half wattage and make them last longer... they already last at least 50,000 hours so potentially double.
 
For instance my 800W Cree cob puts out 4.53 umol/s/W with losses included.
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Oh wow you're right I do stand corrected. That is an awesome light! I had no idea the Cobs efficiency had gone up that much already. I was mainly using info off this post by greengenes from last year:

Gavita double ended...

Still gavita is pretty darn efficient compared to most lights.
 
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kelly1376 said:
Oh wow you're right I do stand corrected. That is an awesome light! I had no idea the Cobs efficiency had gone up that much already. I was mainly using info off this post by greengenes from last year:

Gavita double ended...

Still gavita is pretty darn efficient compared to most lights.
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It happens, and they are still getting more efficient still! The Gavita is only about 10% more PAR output than a normal HPS.

Thats straight from their website.

"What are the benefits of Double Ended bulbs?

1. Double Ended HPS bulbs degrade slower than traditional single ended HPS bulbs. In fact, after 10,000 hours double ended lamps will still output approximately 90% of their original intensity.

2. Double Ended HPS bulbs are more stable than traditional single ended HPS bulbs, and this allows them to have a 10% increase in light intensity and PAR output over traditional single ended HPS bulbs.

3. Double Ended HPS bulbs emit more UV and IR light than traditional single ended HPS bulbs, increasing the potency and essential oils of oil producing plants."

While Im over here considering a Citi LED 058 that produces 60% More PAR Watts at the same wattage than my current setup...

Im Just not impressed with it.
 
Heres the whole calculation so you have all the details.

CXB3590DB36V4000K 16 COBS @1.4A ON 1.813 PROFILE HEATSINK
25 SQ.FT. CANOPY 94% EFFICIENT DRIVER @10 CENTS PER KWH
Total power watts at the wall: 831.91
Cobs power watts: 782
Total voltage forward: 558
Total lumens: 154163
Total PAR watts assuming 10% loss: 430
Total PPF: 1947.9
PPFD based on canopy area: 838.68
PAR watts per sq.ft.: 17.2
Cob efficiency: 61.03%
Power watts per sq.ft.: 31.28
Voltage forward per cob: 34.89
Lumens per watt: 197.14
Heatsink riser thickness / number of fins / fin's length: 0.3in/6/0.95in
Heatsink area per inch: 100.94 cm^2
Total heat watts: 305
umol/s/W / CRI: 4.53 / 80CRI
COB cost dollar per PAR watt: $1.87
Electric cost @12/12 in 30 days: $30.45
Electric cost @18/6 in 30 days: $45.42
Cost per cob: $50.17
Total cobs cost: $803
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After looking at that chart I'm a bit confused. Isn't total Umol is the same as PPF? So PPF/total watts = efficiency? Based on that I'm getting 2.34 umol/watt for that CXB setup.
 
kelly1376 said:
After looking at that chart I'm a bit confused. Isn't total Umol is the same as PPF? So PPF/total watts = efficiency? Based on that I'm getting 2.34 umol/watt for that CXB setup.
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You have to account for COB efficiency as they are more efficient while being under driven.

To my knowledge the math works out, or its a bug in the program. But this is how you get the numbers. keep in mind that this is a 5x5 area


Step 2. Next calculate (or measure) the area you wish to illuminate in square meters.

Example: For a 12 meter x 6 meter area, this = 72 sq. meters.

Step 3. Area x required PAR watts per square meter = total PAR watts required

Total PAR watts required = 85 PAR watts/sq. meter x 72 sq. meters = 6120 PAR watts

Step 4. Estimate PAR watts required at source (typically 50% higher than in step 3)

If half the light is lost in the fixture, walls, etc. twice as many PAR watts are needed from the source. If 1/3rd of the light is lost (a reasonable estimate for most cases), then 50% more PAR watts are needed from the sources (lamps) than the figure calculated in step (3).

Therefore (1.5) x 6120 =9180 PAR watts.

Step 5. Select a lamp of appropriate wattage (e.g. 400 watt, 1000 watt, etc) and calculate its PAR watt rating.

A 400 watt lamp may have 140 PAR watts, a 1000 watt lamp may have 380 (or 420) PAR watts. Higher wattages mean fewer fixtures and are therefore more economical; however they lead to greater variations in light level. Be alert for the phenomenon of photomapping where plants in areas of higher illumination grow taller than those in darker areas, essentially mapping out the irradiance contour for the area! For purposes of this example, we will select a 1000 watt lamp with 400 PAR watts.

Remember that these lamp ratings refer to initial light values, and all light sources depreciate over the life of the lamp. If you are designing to average or maintained light levels, start at 20% to 30% higher. Be sure to relamp before the depreciation reaches an unacceptable light level.


Also side note, PPF is pointless as stated before... You need to know PPFD to make sure you have an efficient spread of light... hot spots are for the weak. PPF is the same as the hot spot in the middle light trails off much faster and is this way makes the PPFD reduce as well.
 
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Shugglet said:
And to bring it back on topic, it will be probably ~10-20yrs easy before your price points see the light of day, so youll easily be able to pay off that shiny new Gavita long before weed prices bottom out.
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10 to 20 years after federal legalization to hit low 3 digit pound prices???
 
I dont think it will take 20 years from now. Hope not. And less than 10 i believe. Hell..theres no telling. Paying attention to what the mpp is doing state by state is key.
 
MeGaKiLlErMaN said:
It happens, and they are still getting more efficient still! The Gavita is only about 10% more PAR output than a normal HPS.

Thats straight from their website.

"What are the benefits of Double Ended bulbs?

1. Double Ended HPS bulbs degrade slower than traditional single ended HPS bulbs. In fact, after 10,000 hours double ended lamps will still output approximately 90% of their original intensity.

2. Double Ended HPS bulbs are more stable than traditional single ended HPS bulbs, and this allows them to have a 10% increase in light intensity and PAR output over traditional single ended HPS bulbs.

3. Double Ended HPS bulbs emit more UV and IR light than traditional single ended HPS bulbs, increasing the potency and essential oils of oil producing plants."

While Im over here considering a Citi LED 058 that produces 60% More PAR Watts at the same wattage than my current setup...

Im Just not impressed with it.
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LEDs have less intensity than HID lights because they have multiple sources of light instead of a single point, this is due to the inverse square law. Basically LEDs have to be hung closer to the plants which makes them have a smaller footprint. One 1000w gavita can cover a 6x4 and be hung much higher than an LED can. Not to mention COB's lack spectrum, hardly any far red and no inferred and no uv.
 
Yodaweed said:
LEDs have less intensity than HID lights because they have multiple sources of light instead of a single point, this is due to the inverse square law. Basically LEDs have to be hung closer to the plants which makes them have a smaller footprint. One 1000w gavita can cover a 6x4 and be hung much higher than an LED can. Not to mention COB's lack spectrum, hardly any far red and no inferred and no uv.
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Once I get my par meter Ill prove that wrong. I know what Im getting in lumens between the DE I have and the COBS and the DE is lacking. Keep in minds thats 1000W compared to 800 COB. The penetration is much better on the COBs but since I scrog that doesnt really matter anyways. Name one light that can cover a 5x5 with 830PPFD at 24in at 800W and ill buy it... But you cant because there isnt one besides a DIY cobs setup.
 
MeGaKiLlErMaN said:
Once I get my par meter Ill prove that wrong. I know what Im getting in lumens between the DE I have and the COBS and the DE is lacking. Keep in minds thats 1000W compared to 800 COB. The penetration is much better on the COBs but since I scrog that doesnt really matter anyways. Name one light that can cover a 5x5 with 830PPFD at 24in at 800W and ill buy it... But you cant because there isnt one besides a DIY cobs setup.
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ummm 1000w hps will do higher than that not even a DE one is needed a normal 1000w hps does 940 par at 27 inches height, that's not even a DE bulb/fixture.
digilux-grow-bulb-results.jpg
 
read this, I think it will help you a lot.

https://en.wikipedia.org/wiki/Inverse-square_law

that's shows that the stronger light source will be able to be hung higher because it has a higher initial value.
read this data sheet

http://www.cree.com/~/media/Files/C...Modules/XLamp/Data and Binning/ds CXB3590.pdf

shows a single cxb has a max lumen output of 15k lumens, a single 1000 w hps bulb has a lumen output of 155k lumens (10x more) so you can hang the single source higher since its initial value is 10 times more.
 
Anything past 1500 is waste(unless youre running CO2 and over 87F in the room). When you average those numbers you get 665 PPFD @27" and 1026PPFD at 15" and thats 1000 Watts. Im getting 830PPFD at 24" so.... Unless youre claiming that those extra 3in make up the difference then that means youre paying more for less light... And those look to be a 3x3 not numbers for a 5x5... thats a big difference.
 
MeGaKiLlErMaN said:
Anything past 1500 is waste(unless youre running CO2 and over 87F in the room). When you average those numbers you get 665 PPFD @27" and 1026PPFD at 15" and thats 1000 Watts. Im getting 830PPFD at 24" so.... Unless youre claiming that those extra 3in make up the difference then that means youre paying more for less light... And those look to be a 3x3 not numbers for a 5x5... thats a big difference.
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Any pics of of your side by sides you have going on?
 
sixstring2112 said:
Hey megakillerman,what meter did you end up with? Im seriously looking at the apogee meters,just not sure which one to get.
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Shoot I really dont see a huge difference in them performance wise. The video here makes them look like they read the same way give or take how much side light they take in.

Then theres this video... Where a guy uses the sensor of a good one with the display of a multi-meter... and it works just as good for like less than $100
 
MeGaKiLlErMaN said:
Anything past 1500 is waste(unless youre running CO2 and over 87F in the room). When you average those numbers you get 665 PPFD @27" and 1026PPFD at 15" and thats 1000 Watts. Im getting 830PPFD at 24" so.... Unless youre claiming that those extra 3in make up the difference then that means youre paying more for less light... And those look to be a 3x3 not numbers for a 5x5... thats a big difference.
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That's for a 5x5 and that's full spectrum with IR , and lots of FAR RED, something COBs lack not to mention that's a SINGLE ENDED 1000w HPS , DE lights are even higher PAR numbers.
 
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