Heatsinks for DIY LED lamps

AllDayToker

AllDayToker

Well-Known Member
Thanks for all the information @SupraSPL

I do keep my plants under a scrog, so the canopy is always real even. I don't mind building one big one or two smaller ones. Figured I'd stagger them either way.

I just would like to have room for adding COBs, drivers, fans later on. Figured the big one would be better for that. But upgrading on the same heatsink isn't completely necessary, would just be nice. I can always upgrade buy adding more separate builds.
 
Hampsteri

Hampsteri

Well-Known Member
Friend gave me a hs and its 5900cm2. Pretty much like a 5.88" profile. I thought that it would be just enough to 300W worth of cobs if i use it with a fan. Do u guys think that im pushing limits here maybe?
 
SupraSPL

SupraSPL

Well-Known Member
About 23" long? I figure it would be good for about 150W of heat active cooled, so if your COBs are running at about 50% efficiency that matches up.
 
CanadianONE

CanadianONE

Well-Known Member
Any downside to overcooling? Example 3 CXB3070 AB 1.4A on 4.6 serrated 30". Theoretically that sink can passive cool those COB's but what if you added a low CFM fan to it? Any downside to this other then using electricity to power fan.
 
SupraSPL

SupraSPL

Well-Known Member
The are a few, as you said if you use too much fan power it represents a loss of system efficiency which we pay a lot for efficiency in the first place. Second downside if you spend more on heatsinks and get a very small gain, you could have spent the $ on running softer and gain significant efficiency or spend the $ expanding the system. But if you already have extra heatsink on hand might as well use it all.

Another issue worth considering, if the heatsink profile is wide and has tall close fins with lots of active cooling power, you might end with the light overly concentrated and requires more vertical height to spread it out.

I would classify the 4.6" profile as active cooling friendly but passive cooling unfriendly. With a decent breeze blowing into that 30" bar you could cool 257 Watts of heat.
 
Last edited:
CanadianONE

CanadianONE

Well-Known Member
SupraSPL said:
The are a few, as you said if you use too much fan power it represents a loss of system efficiency which we pay a lot for efficiency in the first place. Second downside if you spend more on heatsinks and get a very small gain, you could have spent the $ on running softer and gain significant efficiency or spend the $ expanding the system. But if you already have extra heatsink on hand might as well use it all.

Another issue worth considering, if the heatsink profile is wide and has tall close fins with lots of active cooling power, you might end with the light overly concentrated and requires more vertical height to spread it out.

I would classify the 4.6" profile as active cooling friendly but passive cooling unfriendly. With a decent breeze blowing into that 30" bar you could cool 257 Watts of heat.
Click to expand...
Yeah kinda figured lol I will have to do some more digging. Trying to find a profile in the 30" range that will give good spread (12" OC) for 3 or something around 42' for 4 I like the 1 light per sq/ft idea.
 
SupraSPL

SupraSPL

Well-Known Member
Sounds like you are working with 82.5 Watts of heat. For 30" length passive cooled, the 7.28 is good for 86 Watts of heat a good match. If you go with active cooling the 3.5" X 30" is good for 95 Watts of heat so you could use something as simple as a single 80mm fan in the center.

3.5"X36" example, handling 85 Watts of heat
DSC08567a.jpg
 
CanadianONE

CanadianONE

Well-Known Member
SupraSPL said:
Sounds like you are working with 82.5 Watts of heat. For 30" length passive cooled, the 7.28 is good for 86 Watts of heat a good match. If you go with active cooling the 3.5" X 30" is good for 95 Watts of heat so you could use something as simple as a single 80mm fan in the center.

3.5"X36" example, handling 85 Watts of heat
View attachment 3497200
Click to expand...
Thanks for the suggestions. Both enticing options. Maybe I will experiment with both on next build. Working with Rosewill RCX-Z1 for this one. Would be nice to have a single chunk of aluminum and one fan rather then three or none at all for that matter.
 
AllDayToker

AllDayToker

Well-Known Member
@SupraSPL hey thinking I might like the 8.46" X 62" a little better then the two 10" by 28".

I'm trying to get a plan drawn out for spacing the CXBs and don't know the exact coverage each. Obviously I'll be putting them staggered in a zigzag pattern for best coverage, but just don't know the best spacing.

My canopy is not very deep, with the scrog, so wide coverage is more what I'm looking for compared to depth intensity.
 
Abiqua

Abiqua

Well-Known Member
@SupraSPL

when you get a chance......I know you have @'s thrown your way constantly :)


3.5" Heatsink USA Profile....42" = 48 watts roughly, passive? correct...... Need to clear something up, but I believe this is correct, Many Thanks! :peace:
 
SupraSPL

SupraSPL

Well-Known Member
AllDayToker said:
@SupraSPL hey thinking I might like the 8.46" X 62" a little better then the two 10" by 28".

I'm trying to get a plan drawn out for spacing the CXBs and don't know the exact coverage each. Obviously I'll be putting them staggered in a zigzag pattern for best coverage, but just don't know the best spacing.

My canopy is not very deep, with the scrog, so wide coverage is more what I'm looking for compared to depth intensity.
Click to expand...
The amount of canopy each will cover depends on power, spacing, lenses, distance to canopy etc. A good starting point, we can space them as wide as possible on the heatsink. This diagram is to scale and you can count pixels with the MSpaint line tool to get the exact distances once you get an idea how you want it set up. I put the COBs on the corners a bit further from each edge and the COBs in the center closer to the edge
846 X 62 400W.png
 
Last edited:
FranJan

FranJan

Well-Known Member
Don't know if this was posted already. I'll delete if it was.

http://www.glaciallight.com/products/skd-stamping-SS120.htm

Features
Rated for 120W CoB or MCPCB LEDs
0.34 °C/W thermal resistance
90° adjustable mounting bracket included
Available in single, double, and triple unit configurations up to 360W
Waterproof LED cover available
CoB LED lens available

Dimension

Accessory
Single unit kits

CT-SS120000AB2001
Double unit kits

CT-SS120000AB3001
Triple unit kits

CT-SS120000AB4001
Glass Cover

CT-SS120000AB1001

 
AllDayToker

AllDayToker

Well-Known Member
SupraSPL said:
The amount of canopy each will cover depends on power, spacing, lenses, distance to canopy etc. A good starting point, we can space them as wide as possible on the heatsink. This diagram is to scale and you can count pixels with the MSpaint line tool to get the exact distances once you get an idea how you want it set up. I put the COBs on the corners a bit further from each edge and the COBs in the center closer to the edge
View attachment 3497734
Click to expand...
Perfect, thank you very much. Going above and beyond as always.
 
You must log in or register to reply here.
Top