Water cooled COBs

Shugglet

Well-Known Member
A small suggestion to improve efficiency Lofty.

Rotate your blocks 180* so the water lines are straight shots across the interior of the light, rather than shooting out and curving beyond the frame of the structure. This should make the pump more efficient without really any major changes and thus it should run cooler.

Catch my drift?
 

Shugglet

Well-Known Member
And the heating part uses only a circ pump for the heating circuit.

This chiller cools my entire op, consisting of water cooled air handlers, cooling coils for RDWC systems as well as the COBs themselves.

TThe unit is rated at 5 Tons, or 60,000 BTu of cooling. If all I was cooling was a rack of COBs, I'd only need a single Ton.
I feel like you could do a DIY version of your setup for a smaller operation at barely a fraction of the cost. Granted it would be DIY and I know how people feel about electronics and DIY water projects, but it could be done. Just some pumps, reservoirs and an AC unit
 

ttystikk

Well-Known Member
I feel like you could do a DIY version of your setup for a smaller operation at barely a fraction of the cost. Granted it would be DIY and I know how people feel about electronics and DIY water projects, but it could be done. Just some pumps, reservoirs and an AC unit
Lol, mine IS DIY, brother.

Of course it can be scaled down, but I would hesitate on the tearing up your own AC unit thing. The reasoning is that it's mission critical and you don't want to have less than extremely reliable cooling equipment.

In that vein, consider the ChillKing line of water chillers carefully. Their units start at about one Ton, 12000 BTu. Nope, they aren't cheap, but they pay for themselves in reduced energy costs just like COB LED does.

I've had very bad luck with Surna and would recommend you stay away from them.
 

Shugglet

Well-Known Member
Lol, mine IS DIY, brother.

Of course it can be scaled down, but I would hesitate on the tearing up your own AC unit thing. The reasoning is that it's mission critical and you don't want to have less than extremely reliable cooling equipment.

In that vein, consider the ChillKing line of water chillers carefully. Their units start at about one Ton, 12000 BTu. Nope, they aren't cheap, but they pay for themselves in reduced energy costs just like COB LED does.

I've had very bad luck with Surna and would recommend you stay away from them.
I guess we have different ideas on what constitutes "DIY". I wouldnt call something you have professionals help/do for you "DIY" lol.

I understand that the chilling part is mission critical, but how is an AC inherently less reliable than your chiller (which btw is just an AC).

After all, I could make one that uses a backup AC, just waiting in case the primary AC fails and it would then be cheaper and more reliable via the redundancy lol.
 

ttystikk

Well-Known Member
I guess we have different ideas on what constitutes "DIY". I wouldnt call something you have professionals help/do for you "DIY" lol.

I understand that the chilling part is mission critical, but how is an AC inherently less reliable than your chiller (which btw is just an AC).

After all, I could make one that uses a backup AC, just waiting in case the primary AC fails and it would then be cheaper and more reliable via the redundancy lol.
You got some strange ideas, brother. What I've done sure as hell wasn't plug n play.

A chiller is similar to BUT NOT THE SAME as AC. You may study the subject on your own, it's not my job to educate you.
 

Shugglet

Well-Known Member
You got some strange ideas, brother. What I've done sure as hell wasn't plug n play.

A chiller is similar to BUT NOT THE SAME as AC. You may study the subject on your own, it's not my job to educate you.
Your chiller was retail bought and your controls were done "by professionals", so what part did you do yourself of this project that you claim is "DIY"?

So am I to understand that because they are not the same, but run on the exact same principals, ACs are less reliable than chillers (you know the actual meaty question that you conveniently chose to completely ignore)?

Are you saying that my DIY chiller with a redundant AC wouldnt be less expensive AND more reliable? Or if I "did my homework" would I come to this conclusion? I think not...

The whole "you not wanting to educate me" is a deflection tactic because you dont have an answer, youre making rather audacious claims and then rather than explaining why you make those claims when asked about it you say "figure it out yourself".

Its really starting to seem like there may be a whole lot of truth to churchhaze's post earlier in this thread lol.
 

Shugglet

Well-Known Member
A chiller cools water, a AC cools air... the only technical difference is in fact just the heat exchanger.
So how long have you been studying the topic of Chillers and Air Conditioners and their subtle differences? Thank you so much for educating me ;)

I now see why tty didnt want to go so far into depth with his explanation in order to educate me. It clearly would have taken far too long.

I also found it amusing that that was what he chose to respond to. Instead of perhaps the reliability nature between the two.
 

Shugglet

Well-Known Member
You got some strange ideas, brother. What I've done sure as hell wasn't plug n play.

A chiller is similar to BUT NOT THE SAME as AC. You may study the subject on your own, it's not my job to educate you.
You can ignore my previous response to this, its just too much fun calling you out on shit lol.

In regards to my "strange ideas" are you referring to my idea of the DIY chiller using 2 ACs for redundancy that would in theory by more reliable and far far cheaper than your setup? If so Im left to assume you imagine I dont know what Im doing so it will be less reliable than your store bought chiller?? Okay, if thats the case, but just fucking say thats the reasoning behind it. Youd make more sense.

Or were my strange ideas the idea that your system isnt really that DIY? If so, again I ask, if your chiller is straight retail and your controls were done by professionals, what exactly did you "do yourself" of the "do it yourself" project?
 

ttystikk

Well-Known Member
A chiller cools water, a AC cools air... the only technical difference is in fact just the heat exchanger.
This, while true, only goes so far. The fact that water is a far more thermally dense fluid than air can be taken advantage of in several ways inside the chiller to improve efficiency, this is what I meant by the two are different.

Two AC units aren't cheaper than one chiller, either to buy or operate. Further, one chiller can automatically handle two bloom rooms on a flip. At small scale, so can minisplits- but only water chilling scales up. Since I'm modeling heat flows of larger facilities, it makes sense to use the tech. At a smaller scale than this, just get a minisplit.
 

jucee

Well-Known Member
Thought I'd share my water cooled COB build here.

I've built 8 light bars with cheapo chinese COBs. The idea being to initially build them cheaply and then swap chips to something more efficient after a couple of grows. As this is a bit of an experiment I didn't want to spend thousands and thousands on expensive COBs from the outset (I knew there was a chance this would fail miserably as nobody else has jumped on water cooling yet).

Anyway I made a steel frame from 4cm flat steel sections. The frame is 100cm long and 25cm wide. I epoxied the water blocks onto a steel frame and then made "clamps" out of flat steel sections and 4mm bolts (epoxy alone was slightly dubious). The water blocks aren't going anywhere when clamped! I then used thermal glue to mount the COBs onto the water blocks. The glue can be separated with a razor blade easily which would make upgrading straightforward.

View attachment 3686113

I've used Meanwell HLG-600H-36A drivers because I have no interest in dimming the lights. They're just over 96% efficient at full power. Each COB is running at 0.835A (16.7A total for 20 COBs).

I've used 8mm ID (14mm OD) hose on the 10mm barbs with 12mm hose clips.

Here's the hoses mounted and wiring done:

View attachment 3686114

View attachment 3686115

I've alternated cheap warm and cool COBs. If I were doing this again I'd pick one and stick to it because the power draw of different chips is unpredictable when running off a HLG-600H in parallel. Certainly when I upgrade the COBs later this year I'll be going for 1 uniform type.

Anyway here's the money shot of the lights in action (excuse the lonely auto):

View attachment 3686119

I made an earlier version of these with voltage controlled drivers and current limiting resistors. That's the 8 COB bar you can see at the top. I learnt a lot from building those which I used to make better lights with version 2 (these 20 COB lights).

The water gets pumped around the system with an Eheim 1250 water pump. All the water flows through the water blocks and then into a car radiator mounted on a timber frame where it's cooled:

View attachment 3686110

I have a 16 inch 1800cfm car radiator fan running off a 12V PSU.

The main advantage of this setup is temps inside the tent are dramatically lower than when running air cooled lights as I'm not relying on the air in the tent to remove the heat any more. When running an 8x4 tent at full blast at 2100W (2x600W and 2x450W lights) the tent stays at 25C under lights and 20C in the shade (room where the tents are located is at 19C). If I run only the 2x600W lights so 1200W total, the temp stays at 22C in the tent under lights. COB surface temp is around 45-55C (measured with FLIR camera).

I could make some improvements but this will do for now :) Promised myself there'd be no more tinkering with lights for 2 grows and have put my tools away!

Edit: I should probably mention cost. £167 for the Meanwell HLG-600H, £60 for water blocks, £10 for hoses, £5 for hose clips, £20 for wiring and terminal blocks, £44 for COBs, £10 for steel, sections, £10 for bolts (inc eye bolts for hanging). £326 approx for each light bar.

£15 for car radiator, £15 for radiator fan, £12 for PSU, £65 for water pump. £107 total for radiator and pump.
That is truly impressive stuff there, I love your grow tent setup! You inspired me to want to do my own water cooled cob diy when I have the budget.
 

sixstring2112

Well-Known Member
This, while true, only goes so far. The fact that water is a far more thermally dense fluid than air can be taken advantage of in several ways inside the chiller to improve efficiency, this is what I meant by the two are different.

Two AC units aren't cheaper than one chiller, either to buy or operate. Further, one chiller can automatically handle two bloom rooms on a flip. At small scale, so can minisplits- but only water chilling scales up. Since I'm modeling heat flows of larger facilities, it makes sense to use the tech. At a smaller scale than this, just get a minisplit.
I think your wrong about mini splits not being scalable. You can get a 4 ton with just 2 indoor heads ,but install a 4,5,6 zone valve and add more heads down the road no problem.these newer units all have ramp up/down technology on the fans,compressors and even indoor units so they are much more efficient than units from just a few years ago.tons of pics on ig of warehouse grows using them and even apartment buildings or office's like this
Screenshot_2016-08-31-22-03-49.png

Dont worry about my battery ,im charging now haha.
 

sixstring2112

Well-Known Member
how much those little mitsus go for?
They are alot like cobs,lots of dif seer ratings and models,low ambient multi zone lol.a typical 2ton high seer with just 1 x 24k btu head is about 500 bucks more than any other brand lol.
Im looking at a 4 ton x 4 zone Fujitsu and a 3 ton x 3 zone fuji right now and its about 10 grand for all the equipment. Same shit in Mitsubishi is about 12k :(
But those prices include all linesets,power boxes,service interrupt boxes,outdoor stands.everything but labor which i will pay in weed and my own sweat
 

loftygoals

Well-Known Member
We generally have cool temps in the UK other than summer days (which are the only time we consistently get above 22C) I'd love to have an underfloor heating setup.

2kW running 24/7 (2 staggered areas running 12h each) would heat up a kitchen and bathroom floor nicely. That's my longterm goal; seems more energy efficient than any other solution when thinking about the bigger picture.
 

jucee

Well-Known Member
We generally have cool temps in the UK other than summer days (which are the only time we consistently get above 22C) I'd love to have an underfloor heating setup.

2kW running 24/7 (2 staggered areas running 12h each) would heat up a kitchen and bathroom floor nicely. That's my longterm goal; seems more energy efficient than any other solution when thinking about the bigger picture.
 
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