Would people buy a heatsink that allows water cooling?

Hi,
I have a couple hundred feet of aluminium extrusions designed for LED COB cooling. The hole in the middle is sized for a 1 1/4 inch NPT thread (standard pipe thread found at any hardware store). I'd need about $2 per inch to cover cost. Is it worth it to sell this stuff?

so the extrusion is a square profile with a round center? is there enough meat in the extrustion to screw on cobs without tapping into the water filled section?

if the entire length is that size thats a fairly heavy water bar

keep in mind that discrete cob-sized cpu waterblocks are less than $5 on ebay and are ready to go with barbed fittings for more reasonable sized flows like 3/8" tubing. so thats what youre competing against

the inability to use holders and overall complexity of the system for limited benefit is prob what dissuades most people. unless you can improve in those areas its likely to remain a small market at best

Got a picture of the extrusion or link?

I started making a light and got distracted with other things. I put a 1 1/4 NPT thread on one end. That is a 1 1/2 inch hole in the middle to give a sense of scale. There is about 5/8 inch between the hole and the LED mounting surface. The LED mounting surface is 2 3/4 inches wide and the shoulder on the sides is 1/8 inch. So, you can mount anything that is 1/8 thick there . In the first pic I have 1 x 1 x 1/8 angle mounted. If you want to mount a wide lenses, just install wider 1/8 plates. These are pretty heavy, about 4.5 pounds per foot. It was designed to put a whole rooms worth of LEDs in series with a lot of recirculating water flow. I'd imagine you could use city or well water to cool and be pretty stealthy.

one of the better designs ive seen.

if you could get the cost down with some volume i think it could have some legs.

since youve got access to the machining, putting tapped holes for 35mm holders every 6" or so would be a bonus

Why not?
Water cooling with COB's can be very efficient, but it is a niche. Prepared heatsinks would be very helpful and could make water cooling more popular. But 4,5pds/ft. sounds not cheap!

Plus fullo water wouldnt that be one heavy somebitch?

Awsome though id definitely do something with it if I had that stock piled lol

Cold$moke said:

Plus fullo water wouldnt that be one heavy somebitch?

Awsome though id definitely do something with it if I had that stock piled lol

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Was thinking the same, but my twisted mind is already thinking of some sort of old fridge/freezer element with a flow through that instead. Make a frame with the ally to mount the cobs, then fix the "element" on top of the frame. Get the pressure right, that should take away a hell of a lot of heat with a LOT less weight.

Or get some 1/4 copper tubing, form your pipework to suit the frame and cobs, pump the water through via a similar "element" external to your tent and you could then blow that heat in to control temps in winter.

Important thing, in my mind, is the cooling of the cobs as the cooler they run then the longer they should last.

I imagine how you reuse the heat to heat up the table on which the pots stand. A kind of underfloor heating...
I usually struggle with too cold root temperatures and with water cooling one could get the heat exactly where it's needed.

Randomblame said:

I imagine how you reuse the heat to heat up the table on which the pots stand. A kind of underfloor heating...
I usually struggle with too cold root temperatures and with water cooling one could get the heat exactly where it's needed.

Click to expand...

Same idea, an old fridge element or similar, pump heat from the cobs to under the pots. Getting the pressure right would likely have to be critical, as to high and the heat won't go to the pots, too low and you don't cool the cobs, so a better idea might be two separate systems with some sort of heat exchanger so you can get the "ideal" pressure on both systems.

CobKits said:

one of the better designs ive seen.

if you could get the cost down with some volume i think it could have some legs.

since youve got access to the machining, putting tapped holes for 35mm holders every 6" or so would be a bonus

Click to expand...

These were designed for a warehouse type room where the lights are mounted and unmoved at ceiling height .

With 1 inch at each end for the threads and 2.125 inch per LED (vero29)
1 + 2.125 * 10 + 1 = 23.25 inches rounded up to 24 inches. $2 * 24 = $48. $48 to cool 10 LEDs isn't bad from where I am.
But that doesn't include packaging and shipping. Two things that could kill this idea.

The buyer would be someone trying to get maximum light in a limited space. Water cooling, would efficiently remove of a good percent of that heat. The idea was to have water in a 55 gallon barrel with 2 pumps, one to move water thru the lights and the other to move water thru a heat exchanger (water to air like the ones used in outdoor boiler installs) mounted outside with a air conditioner condensing fan mounted on it. This should greatly reduce the size of HVAC equipment.

I don't have access to machining. The only machining I would be willing to do myself would be cutting and threading (for a fee) the ends.

ketchup45685224 said:

With 1 inch at each end for the threads and 2.125 inch per LED (vero29)
1 + 2.125 * 10 + 1 = 23.25 inches rounded up to 24 inches. $2 * 24 = $48. $48 to cool 10 LEDs isn't bad from where I am.

Click to expand...

i dont know of anybody using 10 cobs on a 2' bar. typical person uses 1 cob per 12-18" so the heatsink cost would be 2.5-4X as much (disregarding cost of water cooling rig which can be substantial if it involves a chiller)

Randomblame said:

Why not?
Water cooling with COB's can be very efficient, but it is a niche. Prepared heatsinks would be very helpful and could make water cooling more popular. But 4,5pds/ft. sounds not cheap!

Click to expand...

your right it is very efficient.
I could only cut these to length and thread the ends for a fee.
We have a manufacture close to us. It's the packaging and shipping that are going to be pricey.

CobKits said:

i dont know of anybody using 10 cobs on a 2' bar. typical person uses 1 cob per 12-18" so the heatsink cost would be 2.5-4X as much (disregarding cost of water cooling rig which can be substantial if it involves a chiller)

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To make good use of a 2' light bar it would need to be mounted high above the plants. From the experiments I have done. I needed the same distance from the plants as the width of the lighted area. If I want to light a 5 x 5. The lights need the light to be 5 feet above the plants to get fairly good light coverage.

Using a chiller would completely defeat the purpose of water cooling in the first place. The whole idea here was reducing air conditioning size and monthly operating cooling costs.

Other cooling methods would be:

An outdoor heat exchanger like I mentioned before.

City water straight into the lights when the drain. In my area , cost for water is about the same as the electricity for air conditioning for cooling garden. But very stealthy.

Well water straight to lights. A lot cheaper than city water. But, you need to filter the incoming water and figure out what to do with water after it's heated.

Both city and well water ideas will require cleaning of the heat exchangers with something like http://www.nucalgon.com/assets/prodlit/3-130.pdf periodically. you might be able to use white vinegar. But I haven't done experiments to see if the vinegar would harm the aluminium. It works good for copper.

CobKits said:

if the entire length is that size thats a fairly heavy water bar

keep in mind that discrete cob-sized cpu waterblocks are less than $5 on ebay and are ready to go with barbed fittings for more reasonable sized flows like 3/8" tubing. so thats what youre competing against

Click to expand...

After the testing I did last summer, I have to agree. I found that high water flow a cpu waterblock can keep a 250 watt cob stone cold and they are only about $3.50 with free shipping.

The conclusion of my testing was, the aluminum tube others have used is about the best option. It has a enough area, mass and water volume that COBs can survive an interruption of water flow. Stop the flow through a CPU block with a cob pulling 250w and it would be toast in a heartbeat. To water cool cobs, I would use 1 to 1.5 inch tube, the size depending on any holders that might be used. If a cpu block can cool 250w, tubing over 1.5" is overkill in my opinion.

BTW, I water cool strips with 1/2" tube and a $5 pump in a reservoir, works like a charm. 250 watts, only weighs a few pounds with remote driver, and it's quite happy with water or running dry.

1212ham said:

After the testing I did last summer, I have to agree. I found that high water flow a cpu waterblock can keep a 250 watt cob stone cold and they are only about $3.50 with free shipping.

The conclusion of my testing was, the aluminum tube others have used is about the best option. It has a enough area, mass and water volume that COBs can survive an interruption of water flow. Stop the flow through a CPU block with a cob pulling 250w and it would be toast in a heartbeat. To water cool cobs, I would use 1 to 1.5 inch tube, the size depending on any holders that might be used. If a cpu block can cool 250w, tubing over 1.5" is overkill in my opinion.

BTW, I water cool strips with 1/2" tube and a $5 pump in a reservoir, works like a charm. 250 watts, only weighs a few pounds with remote driver, and it's quite happy with water or running dry.

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hi,
I looked at cpu blocks before all this. I couldn't figure out how to mount them without a two part epoxy thermal paste. I wanted to be able to change the LED alone. Also the last thing I'd want in a grow room is 300 little heatsinks and hoses everywhere.

The reason for the size is. When I was designed this. It was for a 24K grow with all the LEDs in series for simplicity. Large Pipe = Large water flow = small difference in temperature between the first LED and the last. The weight wasn't a concern because the lights were not going to be moved after install. Warehouse style: 6 feet over the tops of the plants, 6 foot spacing between light bars, and 12 foot long bars.

These aren't designed for the hobby grower. But that doesn't mean they wouldn't work just as good.

running without water or dry. I can't get my head around that. LEDs still generate alot of heat. I have never seen a cpu water block that could do want your saying. Can you link to that product please?

CobKits said:

i dont know of anybody using 10 cobs on a 2' bar. typical person uses 1 cob per 12-18" so the heatsink cost would be 2.5-4X as much (disregarding cost of water cooling rig which can be substantial if it involves a chiller)

Click to expand...

I'm running 6 COBs per 2" bars. Recycling my 3 year old CXB3070 COBs into something more efficient. Up to 4 AB bin COBs parallel on a 1400mA driver and AD bin in 2 up and 3 up (spacing is different for 2, 3 and 4 up)). Nightmare to wire up though and I hope the hot glue holds Very glad to switch to led strips for the bigger grows.





This way I only need two CPU coolers per 6 COBs/bar since each bar only pulls 100W.


Perhaps chopping up the water cooled part in shorter chunks and putting pipe between them would work for a frame like this. I wouldn't use a whole water cooled extrusion for the full length. Not at those prices at least.

wietefras said:

I'm running 6 COBs per 2" bars. Recycling my 3 year old CXB3070 COBs into something more efficient. Up to 4 AB bin COBs parallel on a 1400mA driver and AD bin in 2 up and 3 up (spacing is different for 2, 3 and 4 up)). Nightmare to wire up though and I hope the hot glue holds Very glad to switch to led strips for the bigger grows.

View attachment 4111735

View attachment 4111736

This way I only need two CPU coolers per 6 COBs/bar since each bar only pulls 100W.


Perhaps chopping up the water cooled part in shorter chunks and putting pipe between them would work for a frame like this. I wouldn't use a whole water cooled extrusion for the full length. Not at those prices at least.

Click to expand...

You can break it up if you want.
Tap:
https://drillsandcutters.com/1-1-4-11-1-2-npt-carbon-steel-pipe-tap/?gclid=Cj0KCQjwkd3VBRDzARIsAAdGzMDBax5Yi4pCJHxN0LL_JJUF9P9fez4IOJAL01j-07Z2yOen0DbjFdYaAlc_EALw_wcB
Wrench:
https://drillsandcutters.com/3-4-1-5-8-adjustable-tap-wrench/

Or the like will do the job.

You need to add the width of the LED plus 1 inch per end for the threads.

To those looking at the price. Water cooling can be many times more efficient. You drive them a lot harder. If your on a budget that means fewer LEDs.

Liquid cooled works great and cheaper than passive cooling pin fins Imo. Look at this thread:
"Pictures of your DIY lights - Post your pics!!!" Theirs alot of good tried n true configurations.
https://www.rollitup.org/t/pictures-of-your-diy-lights-post-your-pics.871625/page-91#post-13791313 Take a good look at T-Times U-bolt style mount configuration this looks like your best and cheapest option for Led mounting, the cooling bar itself is the frame.

That extruded stock you have might even be good for Q/b liquid cooled frame too. If you do build a frame either way, please build it with the drivers mounted somewhere other than on top of the frame, the whole idea of L/c is to get the heat out of the grow tent and some where else.

Id say build a light yourself, show how its done, then the parts will sell themselves if its economical. If your selling, i think shipping is going to be the killer, packages over 39 inches gets to be crazy money to ship out, maybe research that while creating a liquid cooled frame.