Heat from 1200W of 1212's/vero 29's/cxm-22/cxb3590 compared to 2x 600W?
- Thread starter Joe34
- Start date
pop22
Well-Known Member
I think you have had a really good idea switching to cob, from hid lighting. Maybe if you have high temps now, just do 1000w of cobs, then build the extra 200w if you need it.
Your plants would be getting more useable light with 1000w of cob, so why would you want to use the same amount of electricity anyway? I'd cut it by at least 200w.
Do your bit for the environment lol You'd still have far more useable light!
Your plants would be getting more useable light with 1000w of cob, so why would you want to use the same amount of electricity anyway? I'd cut it by at least 200w.
Do your bit for the environment lol You'd still have far more useable light!
mahiluana
Well-Known Member
hi brother - as i run a watercooled 300W led lamp i can give you some data.6 x 50W cheap chin. cob(bridgelux) @ 1,5A /33V
The heat energy stored in water is easy to measure - and pretty exactly.
I was able to store 160W in the cooling water. (54%)
12 x 50W chips @ 750mA(more light) was a little bit less but still > 50%.
And I sucked it only from the bottom of the led chip.
Next time i will measure the same lamp system but with Meanwell driver
and quality chips (Cree, Citis).
Then i plan to measure also the heat quantity ~ from the front side of a chip.
Taking the most sensitive condom i may find - putting a certain volume of water inside and
then glue it onto the chip. ( maybe someone is much faster - and want to try the same)
- So long i guess my lamp generates 70-75% of heat + 25-30% light.
This is much more than most people think - and a great reason to watercool the grow room
and use this heat to rise efficiency of led light > 100%.
The money i can save in my hot water bill compense more or less the electricity bill of my lamp.
I only bought a brand new waterboiler+heatexchanger for just $ 170,-
As a seconary effects eg. you are able to get out superfluous heat of your grow room and
rise humidity... for more info just read my contents.
Energy is energy. That said, the methods for cooling are vastly different and that, I believe, is where a lot of the confusion comes from. Cooling a bulb by passing air over it is far less efficient than strapping a heat sink to the back of a cob and cooling said heat sink.
Joe34
Active Member
@mahiluana Thats a nice build!
I think I need a fresh mind to read your post, too much stats reading today has fried my brain...
thanks!
I think I need a fresh mind to read your post, too much stats reading today has fried my brain...
thanks!
cookie master
Well-Known Member
how are you going to scientifically test for the most sensitive condom?
Raging Stalk
Active Member
It is probably a personal thing.
mahiluana
Well-Known Member
just ask the girl in the video, if she like to popp with - or without water
running a chip watercooled from the top "and" from the bottom must give
a pretty good result of the total heat production of your chip.
To subtract this heat amount from total inverted watts -gives you an idea about the "real" light-efficiency.
remember:
- you will not be able to transfer 100% of the heat and store it in the water.
- part of the light will be transformed into heat.
you can calculate your results here:
https://rechneronline.de/chemie-rechner/heat-capacity.php
The guy in the video explained wrong as he talks about the good heat conductivity of water.
But heat conductivity of water is rel. bad (0,55) - Aluminium is 235.
He should talk about the excellent heat "capacity" of water.
CREE, PHILIPS, CITIZEN, OSRAM ......they all should buy condoms to give us correct
datasheet in the future.
mahiluana
Well-Known Member
BobCajun
Well-Known Member
Or put one side of a thermoelectric cooler plate on the heatsinks and generate power from it, though probably rather low amounts, haven't actually investigated that much. I was just looking at them as an air cooling method without using big noisy compressor type coolers.
luv2grow
Well-Known Member
There we go! , Love seeing people start to question the use of wasted heat which is energy, in grows. I always wanted to see water cooled hid/or led's and the thermal electric capabilities they could produce. Even small numbers start to add up. I think as we get deeper into renewable resources the community will get away from using watts as a common comparison and begin to see energy as amp hours which in the end pushes better wired or more efficiency in the grow area. I guess in the end it's all the same...
Sorry for the off topic reply but I'm just enjoying my morning puff and getting the brain rolling for the day. Digging this thread
CobKits
Well-Known Member
mahiluana
Well-Known Member
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.
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 you help me please !
DesertHydro
Well-Known Member
what i have learned recently is that the heat savings comes from replacing a 1000w hps with 6-700 watts of COB. watt for watt they are about the same. individually the COBs run cooler but when you have a shit ton of them in your room it accumulates just the same if not more since you are no longer air cooled. im thinking of building sheet metal "hoods" that cover the top of my light and have a 6" duct outlet to remove some of that warm air.
DesertHydro
Well-Known Member
thought about that but my arrays are 41x41 and a hood would add 20 pounds to my 45 lb array. just gonna get sheet metal and bend/cut. i may not even bother. just trun the ac down another degree or two lol
CobKits
Well-Known Member
it doesnt work like that. youre not using the waste heat as an energy source, rather youre using additional electricity to move the heat. the heat is still there (more of it in fact), and youve used a bunch more electricity than you would have to plug the 12V fans in directly
BobCajun
Well-Known Member
Yeah if you put power into it, but if you don't put power in but do put one side on a heat source it will put out power, just not much, about 5w usually. Probably not enough for a fan though. As a COB cooler it wouldn't be worthwhile, heat pipes are much better for that, just slightly less effective than water cooled but considerably simpler to work with, I would think.