Which LED ?

Kerovan

Kerovan

Well-Known Member
Enigma said:
I've got 210W of LED that I can put my hand on.

I couldn't do that with the old 250W HPS.
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You can put your hand on the external casing or on the large heatsink, just like you can put your hand on the hood of a hps. The thermal output is the same though watt for watt. Put equal amounts of led and hps by wattage in the same size room and they will heat up the same. I have a 400W hps that heats the tent up by 10° over ambient room temperature. I have approximately 400W of led in the same tent and it heats the tent up by 10° over ambient room temperature.
 
Enigma

Enigma

Well-Known Member
Kerovan said:
You can put your hand on the external casing or on the large heatsink, just like you can put your hand on the hood of a hps. The thermal output is the same though watt for watt. Put equal amounts of led and hps by wattage in the same size room and they will heat up the same. I have a 400W hps that heats the tent up by 10° over ambient room temperature. I have approximately 400W of led in the same tent and it heats the tent up by 10° over ambient room temperature.
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I'm not seeing a drastic change in temperature.

Maybe I have magic COBs from TastyLED.
 
Kerovan

Kerovan

Well-Known Member
Enigma said:
Yes, and I can touch and hold every part of it. Not something I could do with a 250W or even a 150W.
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I can touch every part of my 400W hps except for the bulb. If you are saying your led's don't put out any heat you don't have them turned on.
 
Humple

Humple

Well-Known Member
Like @Kerovan said, take one of those COBs off the heatsink and see if you can keep your hand on it. The heat is transferred to the sink, but it's not like it goes away. It's certainly more widely dispersed, and that seems to give people the impression that LEDs are cooler, watt-for-watt, but that just doesn't compute. At least, it doesn't compute if we're going to bother with pesky things like physics!
 
Getgrowingson

Getgrowingson

Well-Known Member
Enigma said:
Where is your maths?
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1 w equals 3.412 BTU per hour any where you look . 1 w of led is equal to 1 w of hps the same as 2 w of dildo equals 2 w of led and that 2w of dildo will get your women way hotter then 2 w of led lights will. It’s simple thermodynamics. All light is eventually converted into heat no matter what the source ask your buddy @Rahz he will set you straight. The benefit of leds is efficiency. More light produced per watt vs hps or whatever so you can run lower wattage to obtain similar results. The other reason it seems it’s cooler is because the heat is transferred through the heat sink upwards instead of it beaming out as infrared heat coming off the bulb. It may seem cooler but it is putting out the same amount of btu per hour no matter if it’s a led light that gives you a boner or if it’s your girls dildo . It’s called le science
 
Rahz

Rahz

Well-Known Member
It's true that ambient temps, representing total amount of energy in the system would be the same so AC cost should be similar but with similar air exchange canopy temps should drop by some degree because much of the waste heat from LED is moving up from the source rather than being radiated down on the plants.
 
Randomblame

Randomblame

Well-Known Member
Enigma said:
Yes, and I can touch and hold every part of it. Not something I could do with a 250W or even a 150W.
Click to expand...

Then remove the heatsink and try it again for a fair comparision.
Bulbs have no heatsinks, 95% of the heat is removed by only konvection. So bulbs really getting hot.

COB's can not work in the same temperature range and therefor needs heatsinks to suck the heat from the backside and dissipate it over a large area.
If you would run a 150w COB without any heatsink and meassure the temps until it breaks you would probably read 200°C just before it burns out. Would you also try to keep your finger there, LOL?

You need to understand, that light radiation is also a form of heat which is dissipated by the LED. In the moment light hits a surface it's getting converted into heat. Hold your hand below a strong light source and you will imediately feel the heat and it is not only from the IR radiation, which is only a small part of the spectrum.
You would feel the heat also from strong blue light.

If you replace a 400w HPS watt for watt with a 400w LED you release the same amount of heat in your tent. But the LED converts more the energy into light energy and less into direct heat.
Imaging this again:
400w LED: ~50% light + ~50% heat, so 200PAR/w(a form of heat radiation) + 200w direct heat=400w
400w HPS: ~30% light + ~70% heat, so 120PAR/w + 280w direct heat=400w
Especially in a tent where all the light is getting reflected over time you still have to handle with 400w of heat.
Even the sound waves of your 200w speakers will end up in heat.
 
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nicougrik

nicougrik

Well-Known Member
First law of tbmhernodynamics: "THOU SHALL NOT DESTROY OR CREATE ENERGY..in an isolated system!"

Makes sense that x amount of energy (ps: watt is a measure of energy), You cannot creat or destroy that x amount of energy. Energy only gets converted (in this instance) to sound, and mainly light and heat.

Anyway back to the original post..haha

Even though leds are more efficient in terms of output per watt. Im looking for the higher output per dollar (purchade price)
So you tell me. Do i get a 1000w hps at ~300 bucks or those $1000 led rigs ?

As far as i can tell i will get more light per dollar if i go for bulbs. But you tell me, ive been out of the loop for a few years lol.

Also, if i wanted to soread heat out more evenly, wiuldnt a bulb be better ? Since led have heatsinks ?
 
Randomblame

Randomblame

Well-Known Member
Depends on how long you plan to use it!
It probably costs you more than 1000$ but it will pay for itself by the higher yields very quickly. If you get ~800g from the 1000w hps you could get up-to 1200g out of 1000w LED.
50% more yield will compensate for the higher upfront costs very quickly and from then on you will only make profits with LED.
Have a look on ChllLED website, there is a LED cost calculator and a well explained video.

But it seems you have already made your decision. If so, we can close the thread actually.
 
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