noob about to make a final decision. Please help.

[Rahz]

I simply used the same logic you used in post #38 of this thread, and pretty much got the same figure. You got 114. I got 110.

What I figured was total PAR wattage, not by the foot though.

Also, something has me confounded. The image below shows the calculations for 4 * CXB2530. At 0.3A it's pumping out 51 W/Feet² which is more than 3 * CXB3590 @ 0.7A which calculates at 46 W/Feet². 4 * CXB2530 @ $58.32 vs 3 * CXB3590 @ $218.10. That's a no brainer.

Where are you getting your w/sqft figures?

14 CXB2530 at .35 amps would be 12w x 14 = 168 watts / swft.
3 CXB3590 at .7 amps would be 23w x 3 = 69 watts divided by sqft.

If your prices for the 2530 are accurate I think they're a good deal. Are these at Cutter?

 

[Chuff420]

sorry mate did not realise your in OZ, I thought you were referring to USD prices, You need to use the CUTANDROLL discount code that will get you to USD42, equivalent, how many do you need?
Cheers
Mark

That's OK Mark.

Sorry for my sharp reply, but you were the 3rd person in this thread telling me I was paying too much, without possibly reading the entire thread, as I keep pointing out to everyone, I'm in Australia. And when the Director of the company selling the COB I'm thinking of purchasing tells me I'm paying too much. Well, that just hurt.

Anyhoo, at this stage 4 * CSX2530 might be the go.

I'm still waiting for an explanation as to why 4 * CXB2530 @ 0.3A is surpassing 3 * CXB3590 @ 0.7A. There must be a trade off of something but it's not clear as to what that trade off is, otherwise why would anyone bother buying CXB3590?

As soon as I understand exactly what that trade off is, then I'm pretty much ready to go.

Once again for anyone not reading the entire thread. Here are the numbers:


Incidental, the CXB2530s I'm look at are CXB2530-0000-N0UT230H, so they're T2 Bins and not U2 Bins as detailed in the spreadsheet. The datasheet shows T2 @ 3200 - 3440 Luminous Flux & the U2 @ 3680 - 3955, so I'm guessing the T2 Bin will produce less that the U2 detailed. How much significance would this difference make?

Thanks everyone.

 

[Chuff420]

What I figured was total PAR wattage, not by the foot though.



Where are you getting your w/sqft figures?

14 CXB2530 at .35 amps would be 12w x 14 = 168 watts / swft.
3 CXB3590 at .7 amps would be 23w x 3 = 69 watts divided by sqft.

If your prices for the 2530 are accurate I think they're a good deal. Are these at Cutter?

Hey Rahz,

Just passing on what the numbers are telling me. Refer to the graphic in the previous post.

I'm hoping someone can point out my error if there is one before I part with my cash. I'm at the point now where the cheap price of the CXB2530 will more than likely be the determining factor, but I just want to be certain that my understand is correct.

Also, my intention from the very beginning was to use water-cooling in my cabinet build, but now that I have a slightly better understanding of how this all works, I'm wondering whether water-cooling would be overly excessive. If I were to purchase 4 * CXB2530 and run then at 0.3A, would CPU heatsinks with fans be sufficient, or will the heat be excessive in my 4.165668Feet² cab considering that the temperature outside the cabinet could reach 35-40C during hot days in summer. Opinions?

I just had another look at the graphic above and noticed the PPFD values are double for the 3590. I'm guessing that's were the difference lies, and as someone else pointed out earlier I think, forget W/Feet², it's PPFD that counts. I need 8 * 2530 @0.3A to get 508 PPFD & 102 W/Feet² whereas I only need 3 * 3590 @0.7A to get 512 PPFD & 46W/Feet².



So 4, 6 or 8 2530s in 4.165668 Feet² of cabinet?

Thanks.

 

[Rahz]

The T2 bin will be about 15% less light than the U2 bin. Still a good deal as I see they are on sale...

but your spreadsheet doesn't seem to be functioning properly. You can see with your 3590 @.7amps PAR total, 44 -vs- the 2530 @.3amps PAR total of 22, impossible for the W/feet to be higher. Also if you're figuring watts per foot based on a 4.16 square foot area,

3 CXB3590 @ .7 amps = 68.7 watts / 4.16 = 16.51 w/sqft
4 CXB2530 U2 @ .3 amps = 40.76 watts / 4.16 = 9.79 w/sqft

 

[welight]

That's OK Mark.

Sorry for my sharp reply, but you were the 3rd person in this thread telling me I was paying too much, without possibly reading the entire thread, as I keep pointing out to everyone, I'm in Australia.

No Worries, Quilty as charged, I did not read it all
Cheers
Mark

 

[Chuff420]

The T2 bin will be about 15% less light than the U2 bin. Still a good deal as I see they are on sale...

but your spreadsheet doesn't seem to be functioning properly. You can see with your 3590 @.7amps PAR total, 44 -vs- the 2530 @.3amps PAR total of 22, impossible for the W/feet to be higher. Also if you're figuring watts per foot based on a 4.16 square foot area,

3 CXB3590 @ .7 amps = 68.7 watts / 4.16 = 16.51 w/sqft
4 CXB2530 U2 @ .3 amps = 40.76 watts / 4.16 = 9.79 w/sqft

I've gone over my formulas and they all seem fine.

1* CXB3590 @ 0.7A is dissipating 22.9W and 1 * CXB2530 @ 0.3A is dissipating 10.2W. So the 3590 is dissipating more than double that used by the 2530. Could that explain the it?

I'm not saying you're wrong. On the contrary, I'm the noob and I'm doubting my own figures until someone can clearly indicate that they are either all good, or there is a definite problem.

Thanks again everyone. This is all coming together nicely. Learning heaps.

 

[NHS Garden Gurus]

If PAR is what you're looking for check out IGROW

https://nhs-hydroponics.com/igrow-induction-fixture-4ft-400w-w-veg-lamp-complete/

100,000 hour lamp life can't go wrong

 

[Chuff420]

If PAR is what you're looking for check out IGROW

https://nhs-hydroponics.com/igrow-induction-fixture-4ft-400w-w-veg-lamp-complete/

100,000 hour lamp life can't go wrong

AU$1683 and that's before postage to Australia.

That's a bit excessive for 4.165668 Feet² of cabinet.

And how would I get a 4 Foot wide light into a 3.38 Foot wide cabinet?

Thanks anyway.

 

[Rahz]

I've gone over my formulas and they all seem fine.

1* CXB3590 @ 0.7A is dissipating 22.9W and 1 * CXB2530 @ 0.3A is dissipating 10.2W. So the 3590 is dissipating more than double that used by the 2530. Could that explain the it?

I'm not saying you're wrong. On the contrary, I'm the noob and I'm doubting my own figures until someone can clearly indicate that they are either all good, or there is a definite problem.

Thanks again everyone. This is all coming together nicely. Learning heaps.

There's definitely a problem with the spreadsheet. Your watts per foot can't be higher than the total PAR watts. I'm not sure where the numbers in that last column are coming from.

Anyway, if your new footprint is roughly square and 4.16 feet, I would look back over the 4 3070BB option at 1.4 amps (200w total and around 1200 PPFD). If it's more rectangle 3 3590 CD at 1.4 amps (150w total around 1000 PPFD). Also, 8 of the U2 bin 2530s @ .7 amps (200w total) would be about 1100 PPFD, but since the lower bin is the one with the good price, 8 of them (T2) would provide about 950 PPFD. 10 of them would bump it up to around 1200 PPFD using a total of 250 watts.

 

[Chuff420]

There's definitely a problem with the spreadsheet. Your watts per foot can't be higher than the total PAR watts. I'm not sure where the numbers in that last column are coming from.

These are the additional calculations I added to Supra's spreadsheet are in Blue.

• PAR(W)/COB = 50c dissW * 50c %
• PAR (W) Total = PAR(W)/COB * # COBS
• PPF = PAR (W) Total * 4.51
• PPFD = PPF / Area (Metres²)
• W/Feet² = ((# COBS * 50C %) / Area (Feet²)) * 100

Calculations of 1 * CXB3590 for 0.387 Metres² (4.16566 Feet²)

PAR(W)/COB = 22.90 * .6401 = 14.65829
PPF = 14.65829 * 4.51 = 66.1088879
PPFD = 66.1088879 / 0.387 = 170.82399974160206718346253229974
W/Feet² = ((1 * .6401) / 4.16566 * 100 = 15.366082942759720649845354934671

Calculations of 1 * CXB2530 for 0.387 Metres² (4.16566 Feet²)

PAR(W)/COB = 10.19 * .5350 = 5.45165
PPF = 5.45165 * 4.51 = 24.5869415
PPFD = 24.5869415 / 0.387 = 63.532148578811369509043927648579
W/Feet² = ((1 * .5350) / 4.16566 * 100 = 12.8430782289899243050574361663





Calculations seem to line up with the spreadsheet perfectly. I have no doubt what you're telling me is correct, but at the same time I can't find the fault in my calculations.

Can anyone see it?

 

[Chuff420]

Anyway, if your new footprint is roughly square and 4.16 feet, I would look back over the 4 3070BB option at 1.4 amps (200w total and around 1200 PPFD). If it's more rectangle 3 3590 CD at 1.4 amps (150w total around 1000 PPFD). Also, 8 of the U2 bin 2530s @ .7 amps (200w total) would be about 1100 PPFD, but since the lower bin is the one with the good price, 8 of them (T2) would provide about 950 PPFD. 10 of them would bump it up to around 1200 PPFD using a total of 250 watts.

How would 2 * CXB3590 in 4.16 Feet² and 5 Feet tall chamber perform compared to the 3 * CXB3070 & 10 * CXB2530? The measurements are 850mm * 450mm, so more rectangular than square. If I was to run 3070 or 2530, then I would have 2 LED bars spaced evenly from front to back, otherwise a single bar with 3590.

Which of the 3 combinations would run the coolest, and would that be cool enough for CPU heat sinks with fans on the occasional 40c temperature days, or should I stick with water cooling?

Thanks.

 

[Rahz]

W/sqft = #cobs * 50c dissW / area in sqft

Par watts = #cobs * 50c dissW * 50c% as a decimal value
Heat = #cobs * 50c dissW - PAR watts

 

[Chuff420]

W/sqft = #cobs * 50c dissW / area in sqft

Par watts = #cobs * 50c dissW * 50c% as a decimal value
Heat = #cobs * 50c dissW - PAR watts

View attachment 3617744

Aha.

My W/Feet² formula is ((# COBS * 50C %) / Area (Feet²)) * 100. You don't multiply by 100. I removed the multiplication. Can't see how anyone would get to 50W/Feet² though.

What unit of measure is Heat calculated to?

I added a Heat column and this is what I get for 3 * CXB3590 vs 10 * CXB2530 vs 4 * CXB3070

 

[Rahz]

Heat is measured in watts, Total watts - Par watts = Heat watts.

In your formula you're still showing #cobs * 50c%, replace 50c% with 50c dissW.

3 3590 CD at 1.4 amps = 146.55 watts, 82.086 PAR watts, 64.482 heat watts.

In regard to your question on cooling, people have used water cooling but it's overkill especially in your situation I think. If it's something you just want to do, that's cool but not something you should feel is necessary. Once you've figured out what cob combination you will work with and know the heat load then you can figure the cooling needs. For fan cooled heatsinks 40sq/cm of surface area per watt of heat is recommended to keep things under 50C, 120sq/cm per watt for fanless.

 

[Chuff420]

There's definitely a problem with the spreadsheet. Your watts per foot can't be higher than the total PAR watts. I'm not sure where the numbers in that last column are coming from.

These are the additional calculations I added to Supra's spreadsheet prior to my last modification where I remove the * 100 in W/Feet².

• PAR(W)/COB = 50c dissW * 50c %
• PAR (W) Total = PAR(W)/COB * # COBS
• PPF = PAR (W) Total * 4.51
• PPFD = PPF / Area (Metres²)
• W/Feet² = ((# COBS * 50C %) / Area (Feet²)) * 100

My Total PAR Watts is PAR(W) per COB multiplied by the number of COBS.

I can't see anything wrong with the formulas apart from now the W/Feet² column is no longer being multiplied by 100, which I believe it should be.

 

[Chuff420]

DAMN. You're too quick with your last post.

Give me a minute.

 

[Chuff420]

In your formula you're still showing #cobs * 50c%, replace 50c% with 50c dissW.

3 3590 CD at 1.4 amps = 146.55 watts, 82.086 PAR watts, 64.482 heat watts.

OK.

If your statement #cobs * 50c%, replace 50c% with 50c dissW. was referring to my W/Feet² calculation, then I have moded the spreadsheet accordingly, and my PAR(W) Total & Heta Watts line up with your results. Can't see 146.55 Watts anywhere.

 

[Rahz]

That's because your only 50c dissW figure is for a single cob. Multiply that value x 3 cobs for total wattage output. The other two values "PAR (W) Total" and "Heat" do line up with my calculations, and your W/sqft figures are looking correct now.

 

[Chuff420]

Nope. Still can't get 146.55W for 3 * CXB3590 @ 1.4A

My formula before this change for W/Feet² was:

=($N$8*G13*)/$P$4

and now is

=($N$8*(G13*$N$)/$P$4

where:

$N$8 = #COB
G13 = 50c diss/W
$P$4 = Area in Feet²

So I went from:

#COB * 50c diss/W / Area in Feet²

to

#COB * (#COB * 50c diss/W) / Area in Feet²

Here's the results.




Here's my formulas used to generate the above.

 

[Rahz]

In your spreadsheet you have the 3590 at 1.4 amps 50C dissW listed as 48.85, which is for one cob. The total output wattage for 3 is 3 * 48.85 = 146.55. You don't have a column in your sheet for total dissipation watts, that's why you're not seeing the 146.55 figure anywhere. It can be useful though for driver selection, and just to know how many watts the cobs are consuming in total.