Water Cooling CXA 3070

mahiluana

Well-Known Member
how to recapture the heat as energy to use for cooling the room in the summer.
:peace: if you store your produced heat in a heatexchanger outside of your grow room,
you can keep your room temp. low by using hot water in kitchen, shower, washing-machine,
swimming-pool...........the temperature of your lamp can reach ~ the temp. of your incoming service water.

The setup I have is more efficient than 25/75 light/heat, it's closer to 35-45/55-65
how can you be shure to reach 45% light efficiency ???

you can find out easiely the exact values for your chip(s) and driver.
and i guess you will be surprised.

*************************************
i did a 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" 0,175kg of water 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, questions and critic is welcome - on the pics you see simple things for the measurement,
that you can find in smart lighted household.


 

ttystikk

Well-Known Member
(: you can always install a smoke detector with integrated fire sprinkler system - to increase the mess o_O

Watercooled led-light at the end is a great idea if you chose to harvest the produced heat,
which is still ~75% of total input power.

Light-Heat-Cogeneration could also be a very powerfull tool, to combat global warm up.

Tubes, fittings and hoses are not "high-tec" - but yes - a bit of professional control and overview:sleep:? on your own work, is always a good idea.
As usual, Yoda dweeb is talking about things he knows nothing about.
 

ttystikk

Well-Known Member
Makes sense, I'll probably just grab some prefab L channel and hanging wire.

I use the heat to heat a floor in the winter but I'm still researching how to recapture the heat as energy to use for cooling the room in the summer.
The setup I have is more efficient than 25/75 light/heat, it's closer to 35-45/55-65 with the under driven cooled cxa3070 cobs and meanwell drivers. Nitpicky I know but that 10-20% cost me a bit. However that's still a lot of energy to use, between 275-550 watts and I'd love to recapture it.
I keep meaning to buy an automatic extinguisher to mount next to the drivers and wiring but I forget :-?
Peltier cooler. They aren't very efficient.

Send the heat to your hot water tank.
 

QuinndianaJones

Active Member
Peltier cooler. They aren't very efficient.

Send the heat to your hot water tank.
I was thinking Peltier to maybe charge my batteries or something, and possibly a small turbine to take advantage of the current in the cooling reservoir.

:peace: if you store your produced heat in a heatexchanger outside of your grow room,
you can keep your room temp. low by using hot water in kitchen, shower, washing-machine,
swimming-pool...........the temperature of your lamp can reach ~ the temp. of your incoming service water.



how can you be shure to reach 45% light efficiency ???

you can find out easiely the exact values for your chip(s) and driver.
and i guess you will be surprised.

*************************************
i did a 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" 0,175kg of water 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, questions and critic is welcome - on the pics you see simple things for the measurement,
that you can find in smart lighted household.


Cool test, there are a bunch of efficiency discussions in other posts about the Cree CXA 3070 efficiency and my bin info should be at the beginning of this thread. My case temp runs about 43.3°C and I drive it between 700ma and 1400ma with a Meanwell that's also mentioned in my parts list earlier in the thread.
 

mahiluana

Well-Known Member
:peace:(: as we know - he can`t sleep:evil::sleep: with watercooled led light in the same house.

but the huge phallus in his avatar picture shows me with respect - he knows a lot.

i guess he is scared about pirates like me - intending to do buisness down there
in Colorado, making some extra money with watercooled grow lamps during the holidays,
(while living in small cheap dogy-houses )

he don`t know what we know.... in the future many houses will have watercooled led light,
with pv and/or wind power...
 

mahiluana

Well-Known Member
:peace:
thinking Peltier
it`s much better to invert any money in pv panels, wind power or heatexchanger ^


also mentioned in my parts list earlier in the thread.
looking to your posts and pics of your set up - i find your pvc tubes a bit huge and sealing with silicones and other glues a risk, because many plastics are hard to glue with any sealing.
After my first prototypes glueing with plastic end caps - i trust more in rubber together with pressure. --- you don`t need high pressure and waterflow --- i`m fine with 3W / 3m^ / 200L/h water pump for 2 lamps(veg+bloom=900W).
 

ttystikk

Well-Known Member
I was thinking Peltier to maybe charge my batteries or something, and possibly a small turbine to take advantage of the current in the cooling reservoir.


Cool test, there are a bunch of efficiency discussions in other posts about the Cree CXA 3070 efficiency and my bin info should be at the beginning of this thread. My case temp runs about 43.3°C and I drive it between 700ma and 1400ma with a Meanwell that's also mentioned in my parts list earlier in the thread.
Peltier cooler won't charge your batteries. A thermocouple will, but it will need a relatively large Delta T to be worthwhile.
 
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