Cree DIY COB LED? Why do people use white lights?

I like the hard mount the ones like a cpu mount , you can swap COB's easy peasy sell the old tech add new COBs

did ya see the mars hack ?
 
I'll check on that Zombiewoof and edit this post when I find out what the bin was , it was mentioned.

EDIT: the vid I watched the BIN mentioned was VB as having a 7% higher value then lower BIN COB's , I am now thinking the CB BIN is the best just in the 80 CRI not 90 they come in both.
I think bin VB was mentioned because that person has that BIN of COB's for sale.

Cree's website has the BIN numbers and values.

ya got a p/n ? I got the cree pdf CBX chart I don't understand which one you refer to I've yet to watch that GG vid so bare with me

I got post concussive syndrome , math is out but can do a recipe & can hack all day long in my garage


IMO , I would skip the Mars conversion , instead I would keep half and sell half or even all of them to finance the new COB build.

Personally I will keep my current panels and just add some single hanging Cob's to the garden.

The 4 heatsink / fan combos I ordered made it in today , they cost $13 each , four 100w 400-840nm cobs are in route , $25 each.

I am going to hang each one individually where and when its needed included hanging all of them at once from a 5 ft. section of angled aluminum that can be used with or without a light mover.

I will post the build
~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 
I found a 1/4" al plate in my garage that will cut into 2 bar style from the guts of the mars 26" long 6" wide & i'll mount the mars heat sinks above each cob on the bar & have the fans as well , I have a large amount of PC parts to draw from & the mars drivers , I can move to cob's for just the costs of the diodes & mounts .
I'll off the mars led boards on c/l
I used to water cool CPU's has me thinkin water cool a cob ??? a CPU h20 plate is as small as a cob , don't know if I want to do a rad set-up with pump . aircool much easier
I like the CPU coolers set-up Ya did Clean build Bro !
I'll do a build thread when ready still looking at which cob
Grow well grown greasy resin soaked nugs like Growmau5 & GG has done
 
I'm gonna go with 3ft heatsinks, passive most likely, with 4 or so COBs per. CXB3590s CD bin at 3500k or 4000k. I forget who posted a video of someone speaking on 4000k bringing out the colors more effectively, but I need to watch that video again. I'm still debating on tent size...so far 2x4 would work perfectly with 1 of those bars. Youtube is greatness lol.
 
I stumbled on the DIY COB's about 3 months ago. I am very interested as well. What I was reading seemed like the people with electrical engineering backgrounds. My electrical experience is only hooking up car amps |:

That's more than me. I just keep watching and reading the same thing over and over till it clicks. I also have been writing down a lot. It all helps. Videos especially.
 
Water Cooling would work great in a grow room.

Wish I thought of using water cooling before I bought the heatsink / fan combos.

You could use a water barrel and a 12 or 24v magnetic pump to cycle water threw a line of CPU waterblocks.

~~~~~~~~~~~~~~~~~~~~~~~~~

cree_3590_cob.JPG



After this full spectrum build I am going to buy a 3590 with a purpose made reflector for $80 CA online , then water cool it with one of those stand alone waterblock pump radiator combos.
They can be had for $50 $60 bucks online and come complete , perfect for single builds being they are portable.

A standard CPU water block can be found for 20 bucks or less so its a fairly affordable route to go if you have a need to cool more then one of them.


The thing with water cooling is the Cobs could last 1000,000 hrs instead of 50,000 hrs ( I have read )

Water cooling is much more effective at cooling and will cool the Cobs much better.
The CPU Overclockers have proven its benefit

side note:
I think a water cooled cob would *also* look awesome ! :volcano-smiley:
 
Water Cooling would work great in a grow room.

Wish I thought of using water cooling before I bought the heatsink / fan combos.

You could use a water barrel and a 12 or 24v magnetic pump to cycle water threw a line of CPU waterblocks.

~~~~~~~~~~~~~~~~~~~~~~~~~


After this full spectrum build I am going to buy a 3590 with a purpose made reflector for $80 CA online , then water cool it with one of those stand alone waterblock pump radiator combos.
They can be had for $50 $60 bucks online and come complete , perfect for single builds being they are portable.

A standard CPU water block can be found for 20 bucks or less so its a fairly affordable route to go if you have a need to cool more then one of them.


The thing with water cooling is the Cobs could last 1000,000 hrs instead of 50,000 hrs ( I have read )

Water cooling is much more effective at cooling and will cool the Cobs much better.
The CPU Overclockers have proven its benefit

side note:
I think a water cooled cob would *also* look awesome ! :volcano-smiley:




High power LEDs will last about ~45-50,000hrs on average max due to the wear on put on the UV emitters underneath the yellow/orange phosphor coat. The higher output LEDs 3950s have a life average somewhere around 50,000-~55,000hrs. They get plenty hot pushing. They will only last this long if they are given a near perfect heat sink. Ie) copper with a large surface area with active cooling.

Phosphor - Wikipedia
 
Water Cooling would work great in a grow room.

Wish I thought of using water cooling before I bought the heatsink / fan combos.

You could use a water barrel and a 12 or 24v magnetic pump to cycle water threw a line of CPU waterblocks.

~~~~~~~~~~~~~~~~~~~~~~~~~

cree_3590_cob.JPG



After this full spectrum build I am going to buy a 3590 with a purpose made reflector for $80 CA online , then water cool it with one of those stand alone waterblock pump radiator combos.
They can be had for $50 $60 bucks online and come complete , perfect for single builds being they are portable.

A standard CPU water block can be found for 20 bucks or less so its a fairly affordable route to go if you have a need to cool more then one of them.


The thing with water cooling is the Cobs could last 1000,000 hrs instead of 50,000 hrs ( I have read )

Water cooling is much more effective at cooling and will cool the Cobs much better.
The CPU Overclockers have proven its benefit

side note:
I think a water cooled cob would *also* look awesome ! :volcano-smiley:
I got a bunch of new old stock PC water cool radiators 4 fan 3 fan & 2 fan
120mm fan bolt right to them you could even rad outside the tent / take it all out (heat) & save yer atmoshere !
pumps are cheap & effecint to run over fans for cooling / exiting air
spit ballin' here !
mmount cob's on a AL box run water thru !
take a AL box stock about 4 X 2 " 36 " long seal the ends with epoxie with a fitting (h20) run low presure water thru box = silenced cooling also being able to place the cobs closer to each other so you could mix two color temps
 
cmjet4_nofan.jpg


This is a heatsink worthy of a high power LED such as a Cree 3950. This sink is meant to cool 2 E7-48xx/88xx v3 series "Haswell-EX" processors at the same time.

The larger the slab of copper, and the more surface area exposed to the ambient air "via transfer fins" the faster the heat will transfer into the surrounding air. Water coolers will work as active cooling methods. You'll have to custom build the water cooler out of copper refrigerator tubing. You're also going to need a precision temperature controller/ monitor for the water cooling and and diode temps. A water chiller would also be required to keep the diodes in operational temp range. As diodes heat up they rapidly loose their efficiency.
The hotter they get, the more internal resistance builds.

Note if you see the graph in the above link, the LED would have to maintain a standard 45c - 70c to have a +100,000hr life span. Thats a great deal of thermal management.

The formula for LED junction temperature can be calculated using the following formula:

Tj = Tair + (Rth j-a x Pd)


below is an example of a freezer-cooler for a computer. The coolant is ethylene glycol. A similar setup could be used to cool a large bank of Cree 3960s. Personally I wouldn't attempt such a setup unless I had 1500W worth of LEDs to deal with. That would be a very expensive setup.
 
For water cooling all one needs are the cpu waterblocks poly tubing a garbage can /water barrel and a 12 / 24v or 110v pump on a speed controller to fine tune the water flow. You do not even need the speed control its a luxury.

Keeping it simple is not only cheaper it makes for fewer failure points.
 
For water cooling all one needs are the cpu waterblocks poly tubing a garbage can /water barrel and a 12 / 24v or 110v pump on a speed controller to fine tune the water flow. You do not even need the speed control its a luxury.

Keeping it simple is not only cheaper it makes for fewer failure points.

yeah I'd think a rad is needed as that trash can would actually heat up after awhile also you'd have to deal with the water going pond growing on Ya
I say this as been there done that PIA
closed loop & use a silver loop to kill any growth no maintenance
closed loop small rad & small low pressure pond pump
after I hack out the mars 2 's I'll play with a light assy with a water cooler with chaep assed cobs test see what it's like :high-five:
 
My water storage could use a little warmth.

With my particular set up I would not have to worry about heating up the water barrel as its on the basement cement floor which stays cold year round.

It keeps the water barrel at about 55 degrees. I pump rain water into it from a outside barrel.
Its Pure clean PH 6 chlorine free water. I should be drinking it myself..

Being aerated it stays fresh.

Which got me thinking I could use it for water cooling at the same time , but I bought the heatsink fan combos already so missed out on that.
Maybe in the future I'll do it.
It would work very well in the summer to keep the heat down.

water cooling in a basement with a cement floor is a piece of cake , in a apartment etc it would not be as cold but could be designed to be effective.

Using a import car radiator (with antifreeze) and a 12v rad fan as the main rad to cool a line of waterblocks would work for those without the cold water storage.
I like that idea :volcano-smiley:


A Semi's Radiator could cool a pretty big grow :volcano-smiley:
 
I am thinking water cooling will achieve those numbers.
As you speed up the water flow it lowers the temperature progressively.

Using 55 degree water will give it a big head start for someone with cold water storage.

Also they sell chillers for fish tanks and hydroponics that could keep the water reserves temperature in check if you
wanted to use that method.

Note if you see the graph in the above link, the LED would have to maintain a standard 45c - 70c to have a +100,000hr life span. Thats a great deal of thermal management.


1000,000 hrs is 11 years of solid 24 hour use and 50,000 is only 5.5 years.

My Led panels are a year old , I used 24hrs on them for the last 4 months , time is ticking away.
 
Yes, that was where I was going. Indeed active cooling is good as long as it is a closed loop, with some way of cooling the coolant down very quickly. A Peltier cooler would be effective for this. You need copper for the LED base to achieve quick thermal conduction to the liquid, if you are going to get that 45-70c range. Those Cree 3960s put out some significant heat ( especially the LED die area).

One would have to be very careful using the waste heat to heat up water for hydroponics or other... the reason is that copper builds an oxide layer very quickly. The oxide layer is in fact insulating, thereby diminishing your thermal conductivity. Also dissolved minerals can corrode copper over time as well.
 
I remember reading that cooper can cause a mineral lock out in hydroponics systems also heating nutrients is probably not a good idea.

With water storage copper need not be used.

but

*Most* CPU waterblock heatsinks have copper bases so corrosion is a consideration , although they could work excellent for 10 years or more.
As its all new no one has posted tests that I can find.

side note:
Rain water is nearly mineral free and will not build up like common tap or hard water can.
RO water would also work well
 
Any chance you have links to Photos or video of your set up online ? or a journal

I would love to see it , it sounds like I could learn a thing or two from it / you on poundage growing.

budking , i like your handle

There are vids on youtube by two guys in particular, very smart on the diy set ups. I switched to diy cobs about 8 months ago and I will tell you with out a doubt, they cree cobs are the way to go. I have 4 fixtures, 16 cxb3070, 4 hlg 185 1400 drivers with individual heatsink/fan combos. My best run, dwc, one plant....887 grams....21 grams short of 2 pounds. I run 1/2 the electricity, 1/2 the ac to cool my tents and they will bury a 1000w hps. Do t use the cxa, they take 42 watts to fire up, the cxb is only 36 so you can run 4 cxb on a 185 and only 3 cxa. Also, do t use jb weld, you will blow the cob right off your heat sink.
 
:volcano-smiley:
Using a import car radiator (with antifreeze) and a 12v rad fan as the main rad to cool a line of waterblocks would work for those without the cold water storage.
done this before with a dual CPU PC mobo , Over clocked
maintenance was pia
lotta expensive shit gets cooked if anything goes wrong , yer always worried about leaks the whole time
it's not plug & play then forget that's fer sure trust me on this allota time is taken up that is better used on the plants
IMO & actual use on a DIY rig with pumps/barrels
reward / benefit for the labor is not even at all heavy time use / labor for what you'd get
 
copper kills plants , kills beni germs in any grow that uses teas
any copper contact with soil , res water will produce copper chelates IICR that is toxic .
no chemist
but grew orchids for 30 years any copper kills them right off , like copper treated wood on a greenhouse roof dripping down
so a leak would be not wanted if dripped on plants
 
Closed loop is sounding less problematic.

I like the idea of using a large central radiator to cool a string of cob's.
The radiator could be placed in the next room to scavenge the heat from it.

For economy I use a dehumidifier to remove moisture and to retain the lights heat for heating the house.

With my small grow my and the dogs breath has been plenty of Co2 to maintain the plants needs.
I am buying a Co2 meter next month to find out what the levels are, the plants have had fast growth throughout the grows. A good indication the Co2 levels are high enough.

11_week_old_auto_JH_clones_027.JPG



Not much sense in water cooling unless its easier to set up in someones particular case or you want the long led life it could provide.


Nevertheless a good project for a eager diy'er
 
Back
Top Bottom