• Here is a link to the full explanation: https://rollitup.org/t/welcome-back-did-you-try-turning-it-off-and-on-again.1104810/

Water cooled COBs

ttystikk

ttystikk

Well-Known Member
mahiluana said:
I guess many growers have their grow room close to the place where they live.
Many will take a hot shower from time to time:hump:

My waterboiler(heat exchanger) still hangs close to my grow and the way to my bathroom is about 8m.
I connected 2 garden hoses (cold/in + hot/out) to the boiler and take them with me when i take a shower.
I screw off the showerhead of my previous armature and connect cold in/hose. That`s it.

This way you don`t need any changes in plumbing.- Everybody can fit a garden hose - ? :hump:

Since i roll in and out my rollin hoses every day - i feel like a real rollitup firefighter in his daily fight against the lamp fire of my grow room - but also against the planets "big fire" called climate change. If i would live in my own flat - this would be a great reason to do a more fixed installation.

Previous my hot water was prepared by central oil heating.

In the future i will be able to reduce my costs for heating and hotwater down to ~50%.
More or less the amount, that i need to pay for the electricity bill of my grow lamp.

So growing indoor can become a costneutral matter ! :clap::clap::clap::clap::clap::clap::clap::clap:

The whole system is very simple to copy and adapt to your needs, easy to mount and understand.

I think - i`m not the only one, to have the possebility to watch his hot water clock coming down.

:leaf::hug::fire::hug::leaf:
Click to expand...
Heating oil is generally much cheaper per BTU than electricity, but it is an energy savings for sure.
 
S

Shugglet

Well-Known Member
ttystikk said:
Condensation was a problem and also a symptom. The solution to my mind is a different approach. I'm still trying to set up the test rig and we'll see how it works out.
Click to expand...
You going the insulating route or simply running your system at a higher temp? With a dialed in setup like yourself I wouldnt think it would be that difficult to figure out the dewpoint and run your light cooling system a degree or so warmer than the dewpoint.
 
MeGaKiLlErMaN

MeGaKiLlErMaN

Well-Known Member
Shugglet said:
You going the insulating route or simply running your system at a higher temp? With a dialed in setup like yourself I wouldnt think it would be that difficult to figure out the dewpoint and run your light cooling system a degree or so warmer than the dewpoint.
Click to expand...
It's easy to avoid, if you keep your room temp at say 75F then keep the water around 70F or so and you're golden. Just a different way to look at it. Less worry about it heating up your room and more lukewarm water.
 
1

1212ham

Well-Known Member
ttystikk said:
How do you plan to seal the coolant so it doesn't leak between chip and mounting block?
Click to expand...
The blocks will be machined for a rubber seal. It's not something the average person will be doing at home.
Would someone like to offer some insight to the questions I asked?
 
S

Shugglet

Well-Known Member
1212ham said:
The blocks will be machined for a rubber seal. It's not something the average person will be doing at home.
Would someone like to offer some insight to the questions I asked?
Click to expand...
The specs sheets from the manufacturer should list mounting specifications for thermocouples.

But to be honest I see very little gained from having the water in direct contact with the COB vs a standard cooling block. Reason being that water is the weak link in the thermal conductance chain. Maybe Im wrong but it seems to be maximum work for minimal gain.
 
S

Shugglet

Well-Known Member
MeGaKiLlErMaN said:
It's easy to avoid, if you keep your room temp at say 75F then keep the water around 70F or so and you're golden. Just a different way to look at it. Less worry about it heating up your room and more lukewarm water.
Click to expand...
You just reworded the question I wrote with arbitrary temperatures and ignored the insulation route... Unsurprisingly ttystikk responded to you with a quip of common sense that addresses nothing commented on. lol
 
mahiluana

mahiluana

Well-Known Member
MeGaKiLlErMaN said:
if you keep your room temp at say 75F then keep the water around 70F
Click to expand...
This way you have to add extra heat energy to your grow room - to stay in opt. conditions,
because the colder water sucks air temp. down. - In summer under the roof maybe a good idea,
but condensation will be an issue - tty says

The other way round it`s easier.

I measured in my grow room eg. : air 78°F / coolingwater 82°F at state of equillibrium.
300W lamp / 40L water bucket in a windy place. You have to add water to the bucket
every few days, if you run it that way.

S6002014.JPG
 
S

Shugglet

Well-Known Member
mahiluana said:
This way you have to add extra heat energy to your grow room - to stay in opt. conditions,
because the colder water sucks air temp. down. - In summer under the roof maybe a good idea,
but condensation will be an issue - tty says
Click to expand...
You dont have to add heat, you just remove less. Condensation only becomes a problem if your cooling system is below the dewpoint of the grow room. His scenario will almost certainly never result in condensation forming. How do you cool your grow?
 
mahiluana

mahiluana

Well-Known Member
wietefras said:
True, you can go higher than say 50%, but it's relatively expensive. Generally you won't make that extra investment back on power savings, so for most people there is no use for going above 50% right now.
Click to expand...
Yesterday i did a very strange, "exciting" test to know this a bit more accurate.

I wired a Cree 2530/ 5000K/ T4 to a 10W @ 300mA led driver.
I wanted to be shure to use a middle class quality chip and run it under low current efficiency.

My wattmeter showed 10,9W / Vf = 32,4V @ 300mA.

All calculations of temp. change and heat energy you can do here:
https://rechneronline.de/chemie-rechner/heat-capacity.php

I wrapped the chip into a waterfilled "ballon" 0,175L and switched the light on.
After 30 min. the temp. rised from 25,4°C to 40,5°C ---> 6,2W during 1800 seconds.

I estimate the power loss for the led driver ~ 0,5W

So 10,9W(powermeter) - 0,5W(led-driver) - 6,2W(heat energy) leaves 4,2W for the light.
Light efficiency is 38,5%.

Today i repeated the same test, but only 20 min. - I wanted to know more about the heat loss
or heat transfer to the ambient.

After 20 min. the temp. rised from 28,4°C to 38°C --->5,9W during1200 seconds.
Following the water temp. of the ballon cooling down in the room i measured 9 min.
to take the temp. down from 33,7°C to 32,7°C. ---> 1,2W / 9min. = 2,6W / 20min.
This must be more or less my average heat transfer loss to the ambient and is bigger than i thought. You have to add it to the bill.
:cuss:UUUUOUPS - that`s bad for light efficiency.

New calculation is: 10,9W total - 0,5W led driver - 8,5W heat energy --->
my light efficiency is just 26,6%.

Any coments and critic is welcome - on the pics you see simple things for the measurement,
that you can find in smart lighted household.
I would like to see many results from different chips - with different spectrum and power.
Can anybody help me please ! :bigjoint::dunce::fire::dunce::bigjoint::idea::idea::idea:;)

 
ttystikk

ttystikk

Well-Known Member
mahiluana said:
Yesterday i did a very strange, "exciting" test to know this a bit more accurate.

I wired a Cree 2530/ 5000K/ T4 to a 10W @ 300mA led driver.
I wanted to be shure to use a middle class quality chip and run it under low current efficiency.

My wattmeter showed 10,9W / Vf = 32,4V @ 300mA.

All calculations of temp. change and heat energy you can do here:
https://rechneronline.de/chemie-rechner/heat-capacity.php

I wrapped the chip into a waterfilled "ballon" 0,175L and switched the light on.
After 30 min. the temp. rised from 25,4°C to 40,5°C ---> 6,2W during 1800 seconds.

I estimate the power loss for the led driver ~ 0,5W

So 10,9W(powermeter) - 0,5W(led-driver) - 6,2W(heat energy) leaves 4,2W for the light.
Light efficiency is 38,5%.

Today i repeated the same test, but only 20 min. - I wanted to know more about the heat loss
or heat transfer to the ambient.

After 20 min. the temp. rised from 28,4°C to 38°C --->5,9W during1200 seconds.
Following the water temp. of the ballon cooling down in the room i measured 9 min.
to take the temp. down from 33,7°C to 32,7°C. ---> 1,2W / 9min. = 2,6W / 20min.
This must be more or less my average heat transfer loss to the ambient and is bigger than i thought. You have to add it to the bill.
:cuss:UUUUOUPS - that`s bad for light efficiency.

New calculation is: 10,9W total - 0,5W led driver - 8,5W heat energy --->
my light efficiency is just 26,6%.

Any coments and critic is welcome - on the pics you see simple things for the measurement,
that you can find in smart lighted household.
I would like to see many results from different chips - with different spectrum and power.
Can anybody help me please ! :bigjoint::dunce::fire::dunce::bigjoint::idea::idea::idea:;)

Click to expand...
Whoa- science, dude!
 
S

Schalalala

Active Member
mahiluana said:
Can anybody help me please !
Click to expand...
:shock::shock::shock:

Alter, jetzt mal ernsthaft.... haben sie dir auf der Förderschule nicht gesagt das du nicht mit Strom spielen sollst?
In deinem Sicherungskasten haste aber nicht rumgeforscht oder?
Falls doch, dann ist die Wahrscheinlichkeit das du dich mittels dem oben gezeigten "Prüfstand" umbringst gar nicht mal so gering... also hau rein, mach doch noch mal ne Messung, z.B. mit deinem pinken 1800K COB :mrgreen:.
#Darwin-Award
 
S

Schalalala

Active Member
Junge, mach es nicht noch schlimmer und lass den peinlichen Scheiß.
Ich hab tatsächlich eine Frage zum "Versuchsaufbau":
Liegt die LED auf Bild 2 flach auf dem LED-Treiber und das Kondom dann auf der LED? Oder ist die LED im Kondom?
 
S

Shugglet

Well-Known Member
@mahiluana
Something you might be interested in.

Also, estimating your driver efficiency could throw your final numbers pretty far off... Are you sure your driver is ~95% efficient?

Also, your revelation about your heat loss to ambient is why I made my previous comment about using smaller cooling blocks.

Also, in regards to you losing heat to the ambient air, your system is going to have far different characteristics of heat escape than your test setup. You really need to conduct your tests for your losses to ambient on the system itself. Case in point, your light bars will likely radiate heat far better than a water filled condom.
 
Last edited:
mahiluana

mahiluana

Well-Known Member
Shugglet said:
Something you might be interested in
Click to expand...
Hi brother :peace: my main interest was to proof the enormous heat production of led light.

Because many people still believe that led light is the new tecnic with low heat production.
That`s not true. :wall: @ttystikk @wietefras

Finally this morning i found a statement of a prominent member:

http://www.cree.com/~/media/Files/Cree/LED Components and Modules/XLamp/XLamp Application Notes/XLampThermalManagement.pdf

page 5 - heat generation.

mahiluana said:
That`s why i said that a watercooled led light is much better a water heater than a light source.
Click to expand...
So for the future i hope there will be less confusion. (:

Back to the numbers - that means every led light will be a light source with < 25% light efficiency.

*Coolmac watercooled led system* is so far the only way to rise efficiency a huge step forward.

25%:idea: ---------------------------------------------------------~~~> 85%:fire: ----------:wall:

next target will be a watercooled led lens - hunting the remaining 15-20% heat power, wich is still emitted by LES and upside the chip.

S6002029-lensok.jpg
 
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