Water cooling using aquaponics tank

[Ken Beck]

So i came up with an idea to have unlimited cooling on my led cobs i have been testing, i have an aquaponics system that uses a 200gallon tank with water sitting at room temp. The fish in it are tilapia that prefer warmer temps anyways, so i have a long aluminum gpu heatsink that i mounted to the ceiling and have 4cobs with 60°lenses in parallel(for ease of install and cheap power supply). Then i ran a T off of the main line from the tank pump up to the grow bed and used that to flow through the heatsink and back into the tank. The cobs were cheap chinese cobs rated 90-110lumens per watt but im getting readings equivalent to about 158lumens per watt. It's probably also because i am running them well below their rated power. Total cost of led setup is: $40. Seriously, it is beyond cheap lol. Granted im running 5000k lights instead of 3500k-4000k and the wattage on the leds is 50w (until i get my beefier 350w 36v power supply). But this setup shows you can have decent performance for super cheap. Total cost will be up to $65 with the more powerful power supply that im getting today and i will run tests to see how they perform under that. Anyone have good conversion ratios of lux readings to equivalent par values based on color temp and type of light? That would make the testing more accurate and there is no way i can justify buying an actual par reader. Also id like to try some more expensive high wattage cobs that gain a lot of efficiency when underpowered and cooled very well. I want to reach the 200lumen per watt figure with good 4000k led cobs. Any suggestions?

 

[Shugglet]

Anyone have good conversion ratios of lux readings to equivalent par values based on color temp and type of light?

With shitty COBs its tough to say. If you use any of the quality COBs used in most of the DIY builds on the site there are decent conversion factors available (not that it ultimately matters IMO).

I want to reach the 200lumen per watt figure with good 4000k led cobs. Any suggestions?

Prepare to open your wallet lol. But having a 200g rez available for cooling should at least make that part cheaper and easier.

 

[Ken Beck]

With shitty COBs its tough to say. If you use any of the quality COBs used in most of the DIY builds on the site there are decent conversion factors available (not that it ultimately matters IMO).



Prepare to open your wallet lol. But having a 200g rez available for cooling should at least make that part cheaper and easier.

They are crappy cobs, but at $2 each im not complaining lol. Suprising the cheapo cobs have come a long way. They are rated at 100w each but the led diodes used are .5w so 100 of them on the cob is actually 50w. Lumens rating does match epistars specs for the actual chip used and they seem like it was at least matched bins on them as they all light evenly. Idk what ones to test next to be honest. So many different cobs to choose from. Bridgelux or cree are the next brands im looking at. Im only buying 4-5depending on size that can fit the heatsinks im using.

 

[caretak3r]

My current favorite is the Bridgelux V22 Gen7 chips -- they should be slightly (or possibly considerably) better than the citi 1212s for the same price

 

[Los Reefersaurus]

You still haven't gotten rid of the BTU's , they are just hanging out in your rez now. Building and building , I don't want to be the bubble burst-er but this is going to exacerbate your root rot problem. Sorry, I do love to see new and interesting ideas though. Really I hope I am wrong , good luck!

 

[Ken Beck]

The tank is underneath the grow bed separate from the plants....what are you talking about? The tank water is 75.3°f and doesnt even go up a single degree. Thats a lot of water to put heat into. A 300watt tank heater doesnt even raise the water temp more than 5-10degrees above room temp. The entire tank radiates the heat into the room.

 

[Ken Beck]

My current favorite is the Bridgelux V22 Gen7 chips -- they should be slightly (or possibly considerably) better than the citi 1212s for the same price

The citi 1212s are quite a good value from what ive seen. Those have to be run at something like 20w to get 200lm/watt right? Havent looked at the v22 gen 7 chips yet, usually im looking at the 29s but i will definitely check it out. I just got done testing at higher wattages and the efficiency of these cheapos doesnt get any higher. They start dropping off at 25w per cob

 

[Ken Beck]

You still haven't gotten rid of the BTU's , they are just hanging out in your rez now. Building and building , I don't want to be the bubble burst-er but this is going to exacerbate your root rot problem. Sorry, I do love to see new and interesting ideas though. Really I hope I am wrong , good luck!

Follow the 1/4" line coming from the T off of the 1/2" line, it has water coming from the tank directly and the line goes behind the grow bed down into the tank directly. I would never dump the warmed up water from the heatsink down into the grow bed directly.

 

[Shugglet]

You still haven't gotten rid of the BTU's , they are just hanging out in your rez now. Building and building , I don't want to be the bubble burst-er but this is going to exacerbate your root rot problem. Sorry, I do love to see new and interesting ideas though. Really I hope I am wrong , good luck!

200gallons can hold an awful lot of BTUs. 1600btus to raise it one degree F. Not to mention it loses heat from evaporation simple radiation. Or almost 500watts of heat to raise it 1 degree per hour.

 

[Los Reefersaurus]

200gallons can hold an awful lot of BTUs. 1600btus to raise it one degree F. Not to mention it loses heat from evaporation simple radiation. Or almost 500watts of heat to raise it 1 degree per hour.

ok but it is still putting the heat in the rez and the rez in putting that heat in the room ............. at this limited scale and having a source of cool water, it isn't an issue. However I guess I best say it as I don't see the reason of adding complications to this system, would not a passive heat sink work just as well , if not better as you are not relying on a pump to keep your light happy as well as your garden?

 

[Ken Beck]

ok but it is still putting the heat in the rez and the rez in putting that heat in the room ............. at this limited scale and having a source of cool water, it isn't an issue. However I guess I best say it as I don't see the reason of adding complications to this system, would not a passive heat sink work just as well , if not better as you are not relying on a pump to keep your light happy as well as your garden?

The best way to put it is that i am consolidating 2 things into one. I had a tank heater in there running 24/7 300watts of heat just to try and keep the tilapia happy in there. They are ok with 70-75° but would be even better in the high 70's. If i have a higher power led system in there dumping waste heat into the tank, i SAVE 300watts an hour by not using a tank heater anymore. Plus i removed the heater out of the tank so it takes out another thing to deal with. This is all run off of one pump. Originally i had a 12v power supply(for powering my lipo chargers) and i bought a dc-dc converter to power the leds, so it was way more complicated than it is now. The cooling loop also had a 12v pump separately moving the water. So i bought a straight up 36v 350watt adjustable power supply and removed dc to dc converter and 12v power supply. Then made the loop pull from the main line from the tank pump. Super simplified compared to before. Now it is just the 36v power supply and one pump. More light cant hurt with my 4ftx3ft grow bed so i am looking at all options for higher wattage. Im not worried about heat problems at all. As a matter of a fact id love to make more heat, but i still want as much light out of the wattage as possible

 

[Ken Beck]

200gallons can hold an awful lot of BTUs. 1600btus to raise it one degree F. Not to mention it loses heat from evaporation simple radiation. Or almost 500watts of heat to raise it 1 degree per hour.

Yea that tank is not insulated at all lol. Any temp difference between it and the room it dumps into the room. A little late to take it apart and insulate it now...lesson learned for next tank. I was shocked with how much heat it took to get the water up to 80°f when the room is already turned up to 72°. It took 2-300w heaters running 24/7 to hold that temp. I removed both and the room has the heat turned up to 74°. Right now the tank is at 75.6°f with the 4 led cobs running at 265w total. I honestly don't think they can handle much more as the voltage on them is already at 35.3v..maybe i will try a full 36v and see. Worst case i short the cheap leds. No loss there but i dont like all the work involved with taking them off and putting new ones on.

 

[Ken Beck]

So i adjusted the voltage and now i have them sitting at 35.8v with an even 300w from the power supply. these cobs definitely cant take anymore and im already only 50w from the maximum the power supply can do. I think i need to leave that 50w as headroom so it wont die prematurely. Watts from wall is 342 on my outlet meter. I wonder if the lens on the cobs holds heat in. Would the led system run cooler without a lens and just using a reflector to keep light in the grow bed? Btw i know its a weed forum but apparently no other forum has ppl using led cobs for the purpose of growing things. Its a sad world we live in lol.

 

[mahiluana]

id love to make more heat, but i still want as much light out of the wattage as possible

Well done brother - you are at least one of very few "watercoolers" in this univers using the leds`heat production for savings You produce ~240W of heat - and you use it

As far as i see - there is no comercial led light product on the worlds`market - except Coolmac.

Have a look here:

https://www.rollitup.org/t/pictures-of-your-diy-lights-post-your-pics.871625/page-81#post-13441698

with a coolmac system you can store 60% of your electric input (W) as heat energy,
and it doesn`t matter so much if you do it with cree or epistar chips.
As i mentioned it before - Coolmac is a (simple)cooling system for all kind of hp chips and drivers.

Can you send a pic of your lamp(light off) to see some details ?

Some people here (@Shugglet , @frica ) still don`t believe in.
Ignore those discussions about chip efficiency, because your system is even with crapy chips 2-3 times more efficent than any aircooled cree chip in this world.

The same happend with Force-heat coupling many years ago.
http://www.google.st/patents/DE3835502A1?cl=en
So today - smart engines can produce electricity ! and hot water with up to 90% efficacy.
They are very similiar to smart, modern car engines.

I wonder if the lens on the cobs holds heat in. Would the led system run cooler without a lens and just using a reflector to keep light in the grow bed?

For shure theres a heat jam under the lens - take the lens out, bring your light down a bit and use only reflectors.
Wrap an isolating bubble foil around your tank to prevent that tilapia catch a cold - and please don`t run the pond water through aluminium tubes - because the water will concentrate metall-ions during the time. !!! Aluminium is poisson don`t forget
Use a second circuit and a radiator hanging into the pond water.

$2 each im not complaining lol.

That`s what I say and only one reason why Cree chips (will) go down in prices quickly.

Another advantage imo to substitute 1 cree 50W chip by 3 cheap chin. chips is:

You can use different specs in combination sharing the current of one driver.

left driver(50W@1,5A): 1blue+1full spec.380-740nm+1coolw.6000K - 50W chip
on the right: same driver with only 1coolw.6000K 50W chip.

 

[Ken Beck]

I was just thinking of doing that... Unfortunately before i could do it the line got clogged because i dont have a fine filter and the lines to the heatsink are only 1/4" thick....those cobs burnt out fairly quickly without water flowing through the block. Ive got tons of spare cobs though and its no loss to me. Just not fond of the work to get it all mounted again. I'll take pics of the damage and the rebuild later today. Whats the mounting of the coolmac? Can i actually screw down the cobs? Ive been using thermal paste under the cob and epoxy over it to hold it on. The heatsinks are large enough to fit 4-5 cobs on one and only cost me $9 each. Driver is $25 36v 350w with 87% efficiency depending on the load i do on it.

 

[frica]

Ignore those discussions about chip efficiency,

You are ignoring facts.

Facts that the royal blue produces up to 575mw radiant flux while driven at 0.35A (1W)

Tell me, how can your system be 2-3 times more efficient when the Cree is already up tp at least 57%.

Are you going to claim you can get 1.5W out of 1W?

Also you are posting plain misleading shit comparing a CB bin 3590 with a 5000/5700K Epistar chip when 5000/5700 3590s go up to DD.

Of course you must be the one telling people to ignore discussions about efficiency.
Simply because it doesn't suit your agenda.

 

[Ken Beck]

[QUOTE="mahiluana, post: 13443392, member: 947215"
Ignore those discussions about chip efficiency,
You are ignoring facts.

Facts that the royal blue produces up to 575mw radiant flux while driven at 0.35A (1W)

Tell me, how can your system be 2-3 times more efficient when the Cree is already up tp at least 57%.

Are you going to claim you can get 1.5W out of 1W?

Also you are posting plain misleading shit comparing a CB bin 3590 with a 5000/5700K Epistar chip when 5000/5700 3590s go up to DD.

I wouldnt say the epistar leds are better, but they are definitely cheaper per watt. Its a big hit to efficiency but when cooled very well and underdriven it can reach at least within arms length of the cree cobs at rated power levels. Obviously the same thing done to a cree will do a lot better, but initial cost is very high, and if i would have had a catastrophic failure and destroyed the cobs like i just did to my set i was just using, i would probably have cried a bit lol. Especially for initial testing purposes this was definitely the way to go for me. Of course not many ppl do aquaponics or have a large enough tank to support this amount of cooling, so it wont work for 99% but if someone wants to do it, it can be done.

 

[Ken Beck]

Btw i am open to any and all suggestions to improve efficiency and increase output power while keeping in mind cost effectiveness as well. @mahiluana - i considered different specific light spectrums but getting the perfect ratios that will work for each plant was getting quite complicated. And i dont have very sophisticated equipment to show how well it is doing. I cant do a rough estimate of the actual par value when i am using a lux meter. So for those reasons i am continuing on the full spectrum white until i have a good grasp of what it is capable of. Soon i will do thorough testing of it though.

 

[Ken Beck]

I do want to run an idea by everyone though. I saw a video before of someone that submerged an led cob in mineral oil completely and pumped it through to cool it off. This should cool the surface and the entire cob to the same temperature all around. Maybe i could make an acrylic container that the cobs could be mounted in the middle of and have them surrounded in mineral oil and pump the warmed mineral oil through its own closed loop through the aquaponics tank to drop the heat off? I dont know what losses in light there would be travelling through a medium such as that or if it makes the light spread even further, but i am curious if it would work to the point of making the leds hit even higher lumens per watt.

 

[Shugglet]

Some people here (@Shugglet , @frica ) still don`t believe in.

You are trying to sell something using shady tactics. We are not.

How would your cool mac light improve upon his current setup (it wouldnt)?