Led Lights... How Much Heat?

Also it should be noted that the heat generated by LEDs is a different type of heat vs hid. Cascading radiant heat is a different animal than infrared heat. Leaf surface temps should be monitored vs just ambient air temps.

dandyrandy said:

Johnson lights is another.

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Not familiar with johnson but ill have to look into them later tonight.

Bonjour
Every cxb 3590@cd bin @1400mA are 56% efficient...so 56% light and 44% heat...if you take some db bin it is 61% @1400mA...and if you go as low as 700mA with the same it will be 69% efficient...so if you want you could drive them lower...@350mA or less by dimming and get a very low temperature...
Nobody talk about the drivers...it is a source of heat too...when it is cold it is inside the box and when it is hot outside...it is really hot...!
Have a great day ★

http://www.ebay.com/itm/225-Watt-Cree-3590-Meanwell-Led-Grow-Light-/181963341668?hash=item2a5ddc3f64:g:CV4AAOSwZ1lWcO0r
I saw these mentioned, and have no knowledge about them except the parts list. They look good to me, He also has a big one with the CXB3070s instead of the CXB3590
This is a great choice http://www.pacificlightconcepts.com/product/cx300/
I thought I posted this earlier

hotshotisdashit said:

I was wondering how much heat do led lights really put off. I do know that it may vary for different lights. But im speaking about the top lights available right now... Apache tech, area 51, go green, cobs etc. I have used the solar storm 880 but it does produce quite a bit of heat.ooking for 1000 watt equivalent in a 4x4 or 5x5. My 1000 watt hps raises.y temps about 10 (goes from 74 room temp to 82-86) degrees easily. Even though its air cooled. Looking for something where i wont have to use an air conditioner. Give me your opinions or what you use

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The straight up answer is that they put off as much heat as they dissipate power, regardless of efficiency.

If you dissipate 1000W, you generate 1000W of heat.

1000W HPS lamp at 38% efficiency? 1000W of heat.

1000W of CXB at 55% efficiency? 1000W of heat.

dandyrandy had it right in the first response. Heat is heat. a watt of heat is a watt of heat period, regardless of what source it came from. Thats the law of the conservation of energy.The overall efficiency of your light and input wattage will determine how much heat is left over.

So how does a watt convert to a BTU? Its about 3.412 BTU/H per watt/H. So if your whole setup is 1,000 Watts and its a 17% efficient MARS Hydro light setup your getting 170 Watts of usable light and 830 watts of heat or 2831BTU/H of heat being put into your tent.

If you use an HPS setup at 1,000 watts and its 30% efficient your getting 300 Watts of light and 700 watts of waste energy or 2,388.4 Watts

If you built an LED setup yourself and it pulls 1000 Watts and is 60% efficient your looking at 600 Watts of usable light and 400 watts of heat waste or 1,364.8 BTU/H of heat

The best *cost wise* method of removing heat is moving air into your tent and the old air out. The worst methods are A/C and peltier setups. A/C isn't very efficient, so lets say we have that 1000W mars light cause we were idiots and wasted our money, now we need an AC unit capable of removing our almost 3,000 BTU's of heat, in addition to the heat that remains from the inefficient A/C unit, and the extra heat/energy use from the more powerful fan we just had to purchase, and the extra duct work, and the increased holes in our structure to support this... yep. Long story short, that 17% efficient mars light required a ton of ADDITIONAL stuff on top of already having been the worst option and your pulling 2,000 watts and only getting 300 watts of usable light. Something like that.

Do it right, or don't do it. HPS is a fine option, and a real DIY COB LED is a GREAT option, but a mars unit or junk china unit is not an option.

DocCox said:

dandyrandy had it right in the first response. Heat is heat. a watt of heat is a watt of heat period, regardless of what source it came from. Thats the law of the conservation of energy.The overall efficiency of your light and input wattage will determine how much heat is left over.

So how does a watt convert to a BTU? Its about 3.412 BTU/H per watt/H. So if your whole setup is 1,000 Watts and its a 17% efficient MARS Hydro light setup your getting 170 Watts of usable light and 830 watts of heat or 2831BTU/H of heat being put into your tent.

If you use an HPS setup at 1,000 watts and its 30% efficient your getting 300 Watts of light and 700 watts of waste energy or 2,388.4 Watts

If you built an LED setup yourself and it pulls 1000 Watts and is 60% efficient your looking at 600 Watts of usable light and 400 watts of heat waste or 1,364.8 BTU/H of heat

The best *cost wise* method of removing heat is moving air into your tent and the old air out. The worst methods are A/C and peltier setups. A/C isn't very efficient, so lets say we have that 1000W mars light cause we were idiots and wasted our money, now we need an AC unit capable of removing our almost 3,000 BTU's of heat, in addition to the heat that remains from the inefficient A/C unit, and the extra heat/energy use from the more powerful fan we just had to purchase, and the extra duct work, and the increased holes in our structure to support this... yep. Long story short, that 17% efficient mars light required a ton of ADDITIONAL stuff on top of already having been the worst option and your pulling 2,000 watts and only getting 300 watts of usable light. Something like that.

Do it right, or don't do it. HPS is a fine option, and a real DIY COB LED is a GREAT option, but a mars unit or junk china unit is not an option.

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SAY IT AGAIN, A LITTLE LOUDER FOR THE PEOPLE IN THE BACK!

Bonjour
And if you are deaf or/and blind...there's 17 $ panels who perform as well as the mars one...so if you really want to try shitty epi monos...buy the cheapest...like a 18x3w bulb...it will give you an idea of blurple!
Or buy a few 4$ V10 @350mA or less with a cheap driver...and after that you will want to try better...cause even the smallest have good results...
Even at equal w and efficiency cob will have better results because of a better spectrum and light spread...with an hps or a monos panel you have to put the light source in the center of the box...with cob you can split your box by the numbers of cob available...so same amount of light everywhere and better yield...that's why people with 34/36% efficient cob are in the gpw range...!
I guess we should find a way to make a scale of efficiency...how much efficiency% do we need to reach gpw and at what point more light is a waste of $$$!
CU

littlejacob said:

Bonjour
And if you are deaf or/and blind...there's 17 $ panels who perform as well as the mars one...so if you really want to try shitty epi monos...buy the cheapest...like a 18x3w bulb...it will give you an idea of blurple!
Or buy a few 4$ V10 @350mA or less with a cheap driver...and after that you will want to try better...cause even the smallest have good results...
Even at equal w and efficiency cob will have better results because of a better spectrum and light spread...with an hps or a monos panel you have to put the light source in the center of the box...with cob you can split your box by the numbers of cob available...so same amount of light everywhere and better yield...that's why people with 34/36% efficient cob are in the gpw range...!
I guess we should find a way to make a scale of efficiency...how much efficiency% do we need to reach gpw and at what point more light is a waste of $$$!
CU

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So are you saying that multiple (cob) led lights is better than one solid unit?

Would it be the same say if you ran four 250 watt hps lights instead of one 1000 watt light?

hotshotisdashit said:

So are you saying that multiple (cob) led lights is better than one solid unit?

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Yes.

hotshotisdashit said:

Would it be the same say if you ran four 250 watt hps lights instead of one 1000 watt light?

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Sort of, but not really. The LEDs can be placed much closer together than hoods can. Same principle, but not nearly as effective with HID.

Heat wise there is absolutely no difference in 4x 250 watt units vs 1x 1000w so long as those are numbers pulled from the wall

The advantage to having multiple units vs 1 unit is you can usually keep it closer to your plants (critical in indoor lighting, inverse square and all), and a second benefit is with a properly trained canopy you can take advantage of the photosynthetic response curve which greatly favors a lower wattage/sqft per gram yield. You keep everything more evenly illuminated and maximize your space. As you increase light, you don't increase yield quite as much, eventually increasing photosynthetic radiation retards your plat growth and way into crazy land it actually kills your plants

Your best bet is to simply buy an appropriately sized HPS system for your space unless your in an area where electric is double average, you want to be an early investor in the future, or your grow is electrically limited and you *need* a certain production level unattainable with conventional lighting methods.

Something like that, I've had a bit to drink but it sounds right

DocCox said:

dandyrandy had it right in the first response. Heat is heat. a watt of heat is a watt of heat period, regardless of what source it came from. Thats the law of the conservation of energy.The overall efficiency of your light and input wattage will determine how much heat is left over.

So how does a watt convert to a BTU? Its about 3.412 BTU/H per watt/H. So if your whole setup is 1,000 Watts and its a 17% efficient MARS Hydro light setup your getting 170 Watts of usable light and 830 watts of heat or 2831BTU/H of heat being put into your tent.

If you use an HPS setup at 1,000 watts and its 30% efficient your getting 300 Watts of light and 700 watts of waste energy or 2,388.4 Watts

If you built an LED setup yourself and it pulls 1000 Watts and is 60% efficient your looking at 600 Watts of usable light and 400 watts of heat waste or 1,364.8 BTU/H of heat

The best *cost wise* method of removing heat is moving air into your tent and the old air out. The worst methods are A/C and peltier setups. A/C isn't very efficient, so lets say we have that 1000W mars light cause we were idiots and wasted our money, now we need an AC unit capable of removing our almost 3,000 BTU's of heat, in addition to the heat that remains from the inefficient A/C unit, and the extra heat/energy use from the more powerful fan we just had to purchase, and the extra duct work, and the increased holes in our structure to support this... yep. Long story short, that 17% efficient mars light required a ton of ADDITIONAL stuff on top of already having been the worst option and your pulling 2,000 watts and only getting 300 watts of usable light. Something like that.

Do it right, or don't do it. HPS is a fine option, and a real DIY COB LED is a GREAT option, but a mars unit or junk china unit is not an option.

Click to expand...

That's mostly true, but watt is a unit of power, not heat. A BTU is a unit of energy while BTU/h is a unit of power. That means BTU/h can not be converted to W/h. Instead, BTU/h can only be converted to W.

1 BTU = ~1055joule

Heat can be measured in units of joules, BTU, or Watt*hours. Power is measured in W or BTU/h.

hotshotisdashit said:

Would it be the same say if you ran four 250 watt hps lights instead of one 1000 watt light?

Click to expand...

Bonjour
To give you an example 1000w hps is about 38% efficient (38% light and 62%heat) and 250hps 30%...so it is the same because of spreading but with cob more you have at low current more it is efficient and you can spread the light at your convenience (I do 1 hs 1 cob so I am free to place mine where
I need it more and to grow indica and sat dom if I want to...my goal is to have 1 cxb 3590 @1050 mA (35w) over each sq/ft...but I am more than happy with the 4 I already have @1400mA (55w) over my 3.5x3.5 box...more than happy actually!
CU

Ok. A few different opinions by a few different people. So let me simplify this question. Would 600 watts of led have the same temps as 600 watts of hps. All other things being equal.

hotshotisdashit said:

Ok. A few different opinions by a few different people. So let me simplify this question. Would 600 watts of led have the same temps as 600 watts of hps. All other things being equal.

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The question should be to get the same amount of usable lumens how many watts does it take?

dandyrandy said:

The question should be to get the same amount of usable lumens how many watts does it take?

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Yes i agree. And im sure you could get more usable light with the led and same wattage. But im still very concerned about heat. So hypothetically if i replaced my 600 watt hps with 600 watts of cob leds would it produce the same amount of heat in my grow space. Not being a smart ass just curious.

hotshotisdashit said:

Yes i agree. And im sure you could get more usable light with the led and same wattage. But im still very concerned about heat. So hypothetically if i replaced my 600 watt hps with 600 watts of cob leds would it produce the same amount of heat in my grow space. Not being a smart ass just curious.

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I'm replacing my 600 hps with 400 watts of CXB 3590's for the same amount of PAR watts or a little more. A 200 watt cut with the same amount of light will definitely help my temps...

So im guessing about 600 watts of cob can replace 1000 watts of hps?

hotshotisdashit said:

So im guessing about 600 watts of cob can replace 1000 watts of hps?

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Cobs come in lots of flavors, meaning some are more efficient than others.
when run at 56% efficient or higher I think it would be close.