Actionbone
Well-Known Member
Seems that driver can run 4 3590 maybe u can use HLG-120H-C700 to run 3!
Gonna do my first DIY LED with Cree CXA3590
- Thread starter REALSTYLES
- Start date
I just checked those out and they are about $6 cheaper. I am new to all of this electronics stuff so I am trying to learn as much as possible. Seeing that both of these drivers are listed as 94% efficiency, are there advantages other than cost to running the HLG-120H-C700 compared to the HLG-185H-C700. Does the increase in wattage output of the 185 translate into additional heat or reduced efficiency when not being utilized at full capacity?
Lighterfighter
Well-Known Member
SO many Diy threads. @rootney Yes, not running the droiver at full capacity does have an affect on efficiency, eg 92% for not being at full load all the way down to 89%, They were helping me and answered that one, so I thought Id share. I am ganna get the new cxb and use the hlg 120h-1050 and run 2 per driver, 
nogod_
Well-Known Member
Selecting a driver is like being on the price is right. You want to get as close to the max voltage as possible without going over....
PSUAGRO.
Well-Known Member
Selecting a driver is like being on the price is right. You want to get as close to the max voltage as possible without going over....
hilarious .........................
churchhaze
Well-Known Member
Just keep in mind that 420V can kill you.
Lighterfighter
Well-Known Member
bahahahahahah less than that.
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I'm trying to calculate heat sink performance with cxb3590's and I have a couple of questions.
First, is the 4.6" serrated a good profile for passive cooling? I've seen mention of wider spacing with short fins for passive so I don't know if that profile would be a poor choice for that application.
Second, would a heat sink temperature in the 34C - 35C range reduce performance of the cxb3590. I'm not sure how to calculate junction temp but using the formula provided by Getsoutalive I would be running heatsink temps in that range with the set up I am considering.
SupraSPL
Well-Known Member
I would recommend about 75cm²/W for passive cooling if you are going to be using a passive cooling friendly profile (2.08", 3.5", 4.23", 4.9" 5.88", 7.28", 8.46", 10", 12"). The heatsink temp and temp droop will depend on how much air flow the heatsinks get from your circulation fan, the ambient temp and how hard you are running the COBs. I am very happy if I can get 28C between the fins and measure almost no temp droop whatsoever at that heatsink temp with CXA3070s at 800mA (28W).
If my calculations are correct 4 cxb3590's on 48" of 4.6 serrated would come out to 82cm2 per watt. 48" x 342.88(surface area cm2) = 16,458cm2 / 200w = 82.2. If that profile is not good for passive then the next (passive cooling friendly) profile that would provide 75cm2/W or greater at 48" would be the 7.28" @ $2.63 per inch. YIKES!!!
I was hoping to run 2 - 48" rails spaced about 18" apart over a 3'w x 4'l area to cover the canopy more evenly than having one large sink in the center. Maybe I'm over thinking this. Would it be beneficial to have the light spread out over the canopy a bit more? Is it likely that production would increase with better light distribution compared with a large COB/heat sink unit in the center?
I was hoping to run 2 - 48" rails spaced about 18" apart over a 3'w x 4'l area to cover the canopy more evenly than having one large sink in the center. Maybe I'm over thinking this. Would it be beneficial to have the light spread out over the canopy a bit more? Is it likely that production would increase with better light distribution compared with a large COB/heat sink unit in the center?
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getsoutalive
Well-Known Member
Here are the specs for three possible choices at husa
width - c/w/3" - lbs/in
4.60 - 1.40 - .314
5.375 - 1.15 - .37
7.28 - 1.30 - .37
The lower c/w/3" on the 5.375 means it should provide the best performance. Notice that it is almost two full inches narrower and yet has the same weight / in.
Unless I am mistaken, your temp estimate above seems a bit high.
4 * 48.8=195.2w * 48.3% as heat = 94.28w of heat. * 1.4 (c/w/3) / 48 * 3 = a rise above ambient of 8.25c
So if you are getting 34-35 we are starting with an ambient of 28.
I come up with a rise of 6.8c for the 5.375" and 7.7 for the 7.28" widths.
If ambient really is 28, no amount of sink will get you to @SupraSPL's goal.
width - c/w/3" - lbs/in
4.60 - 1.40 - .314
5.375 - 1.15 - .37
7.28 - 1.30 - .37
The lower c/w/3" on the 5.375 means it should provide the best performance. Notice that it is almost two full inches narrower and yet has the same weight / in.
Unless I am mistaken, your temp estimate above seems a bit high.
4 * 48.8=195.2w * 48.3% as heat = 94.28w of heat. * 1.4 (c/w/3) / 48 * 3 = a rise above ambient of 8.25c
So if you are getting 34-35 we are starting with an ambient of 28.
I come up with a rise of 6.8c for the 5.375" and 7.7 for the 7.28" widths.
If ambient really is 28, no amount of sink will get you to @SupraSPL's goal.
alesh
Well-Known Member
Your calculations aren't correct and yet you managed to get pretty close
area = perimeter * length
If you want area in cm^2, you need to convert both perimeter and length to cm, too.
4.6 serrated - perimeter 60.523" = 153.72842 cm
your length 48" = 121.92 cm
area = 153.72842cm * 121.92cm = ~18743 cm^2
--
I like that 2 rails design. I think that this heat sink would be sufficient but 7.28" would be better, no doubt.
SupraSPL
Well-Known Member
width - c/w/3" - lbs/in
4.60 - 1.40 - .314
5.375 - 1.15 - .37
7.28 - 1.30 - .37
The lower c/w/3" on the 5.375 means it should provide the best performance. Notice that it is almost two full inches narrower and yet has the same weight / in.
@SupraSPL's goal.[/QUOTE]
Good catch on the weight difference. The 5.375" has an extra thick base (.375") compared to most others (.275-.3"). The reason I did not list it as passive cooling friendly is because it has close fin spacing (.25") compared to the other profiles (.4"). So although it flows heat faster, it would have a harder time exchanging that heat to the environment passively (assuming equal amounts of surface area used). Same goes for the 4.6" serrated fin, taller fins with closer fin spacing (.32"). But the 4.6 has a relatively thin base (.23"). Also wonder if the horizontal serrations would interfere at all with passive cooling? Both of those profiles should be good for active cooling though.
For a pair of long sinks to cover 4 feet, passive cooling, 200W total, a pair of the 4.23" at 44" ea, would cost $130. So in this case you might be best off with (4) CPU coolers which could do the same job for $40. Passive cooling is more reasonably priced for veg lamps, but can be a large cost for a flowering lamp. On the other hand the heatsinks hold their value and can be repurposed so it is some form of hard asset.
4.60 - 1.40 - .314
5.375 - 1.15 - .37
7.28 - 1.30 - .37
The lower c/w/3" on the 5.375 means it should provide the best performance. Notice that it is almost two full inches narrower and yet has the same weight / in.
@SupraSPL's goal.[/QUOTE]
Good catch on the weight difference. The 5.375" has an extra thick base (.375") compared to most others (.275-.3"). The reason I did not list it as passive cooling friendly is because it has close fin spacing (.25") compared to the other profiles (.4"). So although it flows heat faster, it would have a harder time exchanging that heat to the environment passively (assuming equal amounts of surface area used). Same goes for the 4.6" serrated fin, taller fins with closer fin spacing (.32"). But the 4.6 has a relatively thin base (.23"). Also wonder if the horizontal serrations would interfere at all with passive cooling? Both of those profiles should be good for active cooling though.
For a pair of long sinks to cover 4 feet, passive cooling, 200W total, a pair of the 4.23" at 44" ea, would cost $130. So in this case you might be best off with (4) CPU coolers which could do the same job for $40. Passive cooling is more reasonably priced for veg lamps, but can be a large cost for a flowering lamp. On the other hand the heatsinks hold their value and can be repurposed so it is some form of hard asset.
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getsoutalive
Well-Known Member
Yes the closer fin spacing will tend to hold the heat more. But there two more fins on the 5.375 than the 7.25 which means it also has more surface area /in as well. Remember that the c/w/3" ratings already assume static air conditions, so should take these parameters into account. Assuming accurate ratings, all else being equal, the lower the thermal resistance rating, the more heat it will dissipate.
SupraSPL
Well-Known Member
I dont look at the performance in terms of surface area/inch, just in terms of surface area alone and spread between COBs. In other words, we dont want too much surface area/inch or we lose the ideal spread.
My own setup is a victim of that problem because I am reusing heatsinks that were designed for something else. I am using 6" lengths of the 10.08" profile which has extra thick base, extra thick fins, extra wide fin spacing BUT 2.5" tall fins. So I end up using about 98cm²/W to achieve my temp goals and that relies on the circulation fan to assist. I actually think thhey would perform a lot better if I lopped off some of the fin height LOL.
In the same tent I have a 12" length of 8.46" profile, running at 82cm²/W and it performs about the same in terms of temp but gives me a slightly better spread. If I had to do it all over again I would probably go with 16" lengths of the 4.9" or 5.88" profile.
That is a good question, how are they are estimating the air conditions? That is part of the reason I don't dwell on the C/W/3" rating, I really don't trust it on its own. KNNA taught us to look at surface area first and then optimize it for passive or active. In our grow spaces we do have slight air movement and it seems that the wide spaced short fin combo can really benefit from that.
My own setup is a victim of that problem because I am reusing heatsinks that were designed for something else. I am using 6" lengths of the 10.08" profile which has extra thick base, extra thick fins, extra wide fin spacing BUT 2.5" tall fins. So I end up using about 98cm²/W to achieve my temp goals and that relies on the circulation fan to assist. I actually think thhey would perform a lot better if I lopped off some of the fin height LOL.
In the same tent I have a 12" length of 8.46" profile, running at 82cm²/W and it performs about the same in terms of temp but gives me a slightly better spread. If I had to do it all over again I would probably go with 16" lengths of the 4.9" or 5.88" profile.
That is a good question, how are they are estimating the air conditions? That is part of the reason I don't dwell on the C/W/3" rating, I really don't trust it on its own. KNNA taught us to look at surface area first and then optimize it for passive or active. In our grow spaces we do have slight air movement and it seems that the wide spaced short fin combo can really benefit from that.
I was figuring ambient of 26.1C (79F) with a temperature increase of 8.22C for the 4.6" profile to arrive at 34.7C. I am curious what SupraSPL's ambient temp is for the 28C heatsink recommendation?
getsoutalive
Well-Known Member
6 " of the 10.08 has an overall c/w of 0.8 / (6/3) = 0.4 c/w
12" of the 8.46 has an overall of 1.1 / (12/3) = 0.275 c/w
So we would expect a significantly better performance from the longer narrower unit. Spread of the chips is another subject entirely, based upon models chosen, power applied and height above the canopy. Obviously, there is no one correct answer, each users situation and goals will be different.
12" of the 8.46 has an overall of 1.1 / (12/3) = 0.275 c/w
So we would expect a significantly better performance from the longer narrower unit. Spread of the chips is another subject entirely, based upon models chosen, power applied and height above the canopy. Obviously, there is no one correct answer, each users situation and goals will be different.
getsoutalive
Well-Known Member
Yes, my subtraction was off, 26c not 28. Still a bit warm, imo.
REALSTYLES
Well-Known Member
I dimmed my drivers down to 186 watts and the temp from the heat sinks are 26C right now thanks Supra and I'm wondering if I got the HLG-185H-C500A could I run 5 CXB3590's off one driver? I did the calculation I hope I got it right
SupraSPL
I noticed that you did not list the 5.375" and I figured it was because of the narrow fin spacing.
For the pair of heatsinks I want to use 4 COB's per heatsink, so approximately 400W total. Active cooling would definitely be ALOT cheaper in this application. I was trying to keep it simple in terms of less moving parts to fail and less parts to clean and/or replace. My thought process was along the same line as yours regarding the heatsinks being an asset. Although the up front cost would be much higher, especially for a two rail system, they would be useful for a long time without worrying about fans. I also think the two rail system would spread the light more evenly across the canopy.
I noticed that you did not list the 5.375" and I figured it was because of the narrow fin spacing.
For the pair of heatsinks I want to use 4 COB's per heatsink, so approximately 400W total. Active cooling would definitely be ALOT cheaper in this application. I was trying to keep it simple in terms of less moving parts to fail and less parts to clean and/or replace. My thought process was along the same line as yours regarding the heatsinks being an asset. Although the up front cost would be much higher, especially for a two rail system, they would be useful for a long time without worrying about fans. I also think the two rail system would spread the light more evenly across the canopy.
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