Par mapping the world

Ive been doing alot of par maps lately, and i thought i would share the info i have gathered.

All par maps are done at 24.75 inches (.75 inches for the sensor) and on both a 4x4 and a 5x5, 16 readings for a 4x4 and 25 readings for a 5x5, taken from the center of each square foot.

The par sensor/meter i am using is a Apogee MQ-200

Each fixture is warmed up 25 minutes, room temperature is always 21C

I calculate ppfd by adding up the readings and dividing either by 16 or 25 to get the PPFD.

First up is 4 citizen 1216 3500k cobs in a 36" bar/row configuration driven by a hlg 320h C2100, dimmed to 75%. Max wattage is 330, i have dimmed this one to 246 watts to compare equally to the cree DB fixture which has 4 cree cxb3590 DB bin cobs with a hlg 240h C1750 at same wattage.

each chip is running at about 60 watts.

Citi 1216 fixture:
actual wattage 246 watts
fan wattage: 3.6
4x4 ppfd: 252.31
5x5 ppfd: 208.6
shape of fixture: rectangle, 4 cobs in a row

Cree 3590 DB fixture:
actual wattage: 246
fan wattage: 4.8
4x4 ppfd: 290.75
5x5 ppfd: 227
shape of fixture: square, 4 cobs in a square

When we compare the 4x4 ppfds we have 290.75 - 252.31 = 38.44.
38.44 / 252.31 = 15.23%

When we compare the 5x5 ppfds we have 227-208.6=18.4
18.4 / 208.6 = 8.82%

With this test the cree cxb3590 DB is showing anywhere from a 9% - 15% increase in par, for same wattage over the citizen 1216 fixture.

Id love to hear your feedback, any one else do these types of tests?

thanks

comparing two different fixtures with different optics in an open space like that will always give you a bias

Next up is 12 and 16 cxb 3590 DB's vs a Gavita 1150 on the 1000 watt setting and on the 1150 setting.


Gavita 1150 DE fixture on 1000 watt setting:
actual wattage 1060 watts
BTUS: 3616
4x4 ppfd: 743
5x5 ppfd: 653

Gavita 1150 DE Fixture on 1150 setting(boost):
actual wattage: 1220
BTUS: 4162
4x4 ppfd: 863
5x5 ppfd: 725


12 Cree 3590 DB with HLG240HC1750 fixture:
actual wattage: 806
BTUS: 2750
fan wattage: 16
4x4 ppfd: 852
5x5 ppfd: 719

16 Cree 3590 DB with HLG240HC1750
actual wattage: 1076
BTUS: 3671
fan wattage: 16
4x4 ppfd: 1180
5x5 ppfd: 961


Summary (Using 5x5 ppfd numbers for calculations)

The 12 cree's put out 10% more par then the 1060 watt Gavita and only uses 806 watts.

The 12 cree's put out almost identical PPFD numbers to the 1220 watt Gavita, but only uses 806 watts.

The 16 crees put out 47% more par then the 1060 watt gavita and only uses 1076 watts.

The 16 crees put out 32.5% more par then the 1220 watt gavita and only uses 1076 watts.

CobKits said:

comparing two different fixtures with different optics in an open space like that will always give you a bias

Click to expand...

Its a pretty big bias.

Bar vs square. End.

point being they throw light differently and in an open space you arent catching all the light

you could test the same exact cobs with and without reflectors and see that much difference

in a sphere test its right at 4% difference at all currents

if you want to eliminate bias switch up the chips in the different fixtures

Or perhaps try it in a confined space with reflective walls to give a more real world test result? The Gavita Pro vs the COB fixtures would be interesting to see compared in an actual 5'x5' growtent.

wietefras said:

Or perhaps try it in a confined space with reflective walls to give a more real world test result? The Gavita Pro vs the COB fixtures would be interesting to see compared in an actual 5'x5' growtent.

Click to expand...

your post reminds me of the cree "reference design" test, where they "replaced" a gavita with 550W of medium efficiency leds by discounting all of the light that fell outside the square from the gavita (leds were focused with lenses to stay in the square.

when i tested QBs vs cobs i hung them as high as i could in a 3x3 gorilla tent. the test was essentaially relying on reflection... kind of like a sphere does

CobKits said:

your post reminds me of the cree "reference design" test, where they "replaced" a gavita with 550W of medium efficiency leds by discounting all of the light that fell outside the square from the gavita (leds were focused with lenses to stay in the square.

when i tested QBs vs cobs i hung them as high as i could in a 3x3 gorilla tent. the test was essentaially relying on reflection... kind of like a sphere does

Click to expand...

And the short version was: about 2 cob diodes equal 1 mid-power diode...agree?

CobKits said:

if you want to eliminate bias switch up the chips in the different fixtures

Click to expand...

Yes, i am going to, just waiting on shipment of those units. That will help alot and provide more data.

Although The vero test i did showed advantage to the crees as well, and that test was done with an identical fixture/reflectors, and that data doesnt line up with your data either. Which is weird.

Im well aware that the test isnt perfect. But, The reflectors are both white, plastic, 90 degrees reflectors, but made by different companys. I really doubt it would make that much difference. the reason i dont use reflective walls in this test as it makes it MUCH easier for some one else to do the exact same test and verify the data.

I have par maps of the crees vs gavita at 18" and at 36" as well, they show the same advantage to the crees, ill post it below.

When i test 4 crees, 8 crees, 12 crees or 16 crees, the total ppfd is about equal to the multiplication of the number of chips (8 crees are about double the ppfd as 4, 12 are 3 times as much as 4, and 16 is about 4 times as much as 4 etc). So yes i agree the shape of the fixture can alter the results, but i just dont think it alters it THAT much, but we dont know for sure until i stuff 4 dbs into that 36" row fixture and repeat the test.


thank you for your input, this forum is full of great information and bright minds.

When i see the photos of those fixtures i cant help think , how loud are those speakers

Here is the Gavita vs Cree Db par maps at 18 inch and 36 inch.

Gavita 1150 DE fixture on 1150 watt setting at 18 inches:
actual wattage 1220 watts
BTUS: 4162
4x4 ppfd: 1216
5x5 ppfd: 1131

Gavita 1150 DE fixture on 1150 watt setting at 36 inches:
actual wattage 1220 watts
BTUS: 4162
5x5 ppfd: 423


16 Cree 3590 DB with HLG240HC1750 at 18 inches
actual wattage: 1076
BTUS: 3671
fan wattage: 16
4x4 ppfd: 1545
5x5 ppfd: 1203

16 Cree 3590 DB with HLG240HC1750 at 36 inches
actual wattage: 1076
BTUS: 3671
fan wattage: 16
5x5 ppfd: 619


Summary:

The 16 crees put out 27% more par then the 1220 watt gavita and only uses 1076 watts at 18 inches on a 4x4
The 16 crees put out 6% more par then the 1220 watt gavita and only uses 1076 watts at 18 inches on a 5x5

The 16 crees put out 46% more par then the 1220 watt gavita and only uses 1076 watts at 36 inches on a 5x5


Maybe i should do it at 12" as well? Ill see if i can find the time to setup a tent and do it in a tent too.

Who's fixtures are those that you will be selling?

OneHitDone said:

Who's fixtures are those that you will be selling?

Click to expand...

I assume you are talking to me.

I have tried to pay for advertising here but they wont let me, so i am unsure about what i can say, but they are my fixtures and have been for sale for a few years now.

pirg420 said:

I assume you are talking to me.

I have tried to pay for advertising here but they wont let me, so i am unsure about what i can say, but they are my fixtures and have been for sale for a few years now.

Click to expand...

you are bc blondes? what do they say when you try to pay for advertising?..

CobKits said:

your post reminds me of the cree "reference design" test, where they "replaced" a gavita with 550W of medium efficiency leds by discounting all of the light that fell outside the square from the gavita (leds were focused with lenses to stay in the square.

when i tested QBs vs cobs i hung them as high as i could in a 3x3 gorilla tent. the test was essentaially relying on reflection... kind of like a sphere does

Click to expand...

Exactly, but if you hang the fixtures at the correct heights then it would be a nice comparison showing how well each would perform in a real grow environment.

Even a sphere number can be deceiving since the Gavita has a beam angle of 139 degrees (or something) and it hangs a lot higher. Which means wall losses will be higher. So even if the sphere numbers are the same, the COBs should still beat the HPS on those other parameters.

ganjamystic said:

you are bc blondes? what do they say when you try to pay for advertising?..

Click to expand...

We are a canadian company and they dont do business with other canadian companys. This was their response about a year ago.

yes i am BcBlondes.

wietefras said:

Exactly, but if you hang the fixtures at the correct heights then it would be a nice comparison showing how well each would perform in a real grow environment.

Even a sphere number can be deceiving since the Gavita has a beam angle of 139 degrees (or something) and it hangs a lot higher. Which means wall losses will be higher. So even if the sphere numbers are the same, the COBs should still beat the HPS on those other parameters.

Click to expand...

You have to hang the gavita higher then the leds, because all the heat comes off the bulb in the same direction as the light, with cobs some of your heat comes off the sides/back, depends on where your fans/heatsinks are pointed etc. Theres no way you can hang a gavita at 18" lol, but you can with 12 or 16 leds (i do it frequently at about the 6 week mark when they can take it)

I only have a 4x8 tent, a 5x5 would be preferable, ill have to buy one. Then we can see the differences with reflective walls.

BuddyColas said:

And the short version was: about 2 cob diodes equal 1 mid-power diode...agree?

Click to expand...

more or less, for the cobs i tested, much more testing is in order before we can call that a rule of thumb