LED heat VS HPS heat?

i am currently running a 135w led and a 150 w hps when just running the 150w hps in a 2x2x5.5 tent i had temps around 85+ with just the led i had them steady 80 i am currently running both right now with out my exhuast set up temps reach 90+ but with my exhuast i got it down to 82-85 i was able to get led about 5-7 ins away without bleaching leafs or heat stress but i had the hps about 12-14 ins away and it caused heat stress.

backyardagain said:

i am currently running a 135w led and a 150 w hps when just running the 150w hps in a 2x2x5.5 tent i had temps around 85+ with just the led i had them steady 80 i am currently running both right now with out my exhuast set up temps reach 90+ but with my exhuast i got it down to 82-85 i was able to get led about 5-7 ins away without bleaching leafs or heat stress but i had the hps about 12-14 ins away and it caused heat stress.

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Thanks you for your valued input, +rep

Thanks, are you looking into runiin both at the same time?

puffenuff said:

No need to apologize. You have your opinion and I have mine. I know what my leds produce and what my hps grows used to produce before I made the switch, and I have no regrets. I stand by my statement. Why do you disagree?

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Because I used to use 2 90 watt ufo's and 8 35w cfls in my 3"w x 20'd x 5"h tent and had no issue with heat. Now I have 1 250w switchable and I need to get a cool tube soon so I can keep the tent closed during light cycle. If I don't leave it open the temp gets over 100 degrees.

Howvr, I must admit I am not a techie kind of guy and don't know what the difference of actual draw means to the equation. I am just a simple green thumbed hippie type. I know what my babies like.

To really know, someone would have to test the actual wattage draw of two lamps to properly compare. A 250w HPS doesn't use 250 watts of electricity, and most LEDs are advertised to have drastically higher watts than they actually use. So when testing 250w HPS vs a 230w LED panel for example, the HPS may actually be using 350 watts while the LED may be using 150 watts. Then with LEDs some of the wattage comes from the fans inside so using a watt meter still doesn't directly tell how much wattage of electricity is being used to light the LEDs

backyardagain said:

Thanks, are you looking into runiin both at the same time?

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it could be tempting

As ive followed many threads its the radiant heat thats the most problem.. the radiant heat coming from the HPS is massive causing lots of problems under the hood and ontop of your plants.

With LED theres not much heat being put out towards the plants.. ive seen some growers have successful grows even after the temps reached 100+ in the summer time.

it is tempting haha when i only had 1 running i felt like i was not letting them get to their full potenital since i have 2 lights why not use it and get even better result then if i just ran 1 or the other, and yes it is true that hps radiates alot of heat, as long as you got good circulation in tent with a good exhuast by it i keeps the temps for themmost art under control till outside gets to hot.

With 270w of power confirmed going to the lights I can close my tent up with the inline fan off, with the outside temp at 70 my tent got up to I think 83 all closed up, it took like an hour to heat up. I have had different grow cabinets heat up more than that with 120w of cfls and 3 pc fans for ventilation.

farmari said:

To really know, someone would have to test the actual wattage draw of two lamps to properly compare. A 250w HPS doesn't use 250 watts of electricity, and most LEDs are advertised to have drastically higher watts than they actually use. So when testing 250w HPS vs a 230w LED panel for example, the HPS may actually be using 350 watts while the LED may be using 150 watts. Then with LEDs some of the wattage comes from the fans inside so using a watt meter still doesn't directly tell how much wattage of electricity is being used to light the LEDs

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If your 250w HID is using 350w you better get something checked out, looks to be dangerous!

brotherjericho:7434217 said:

farmari said:

To really know, someone would have to test the actual wattage draw of two lamps to properly compare. A 250w HPS doesn't use 250 watts of electricity, and most LEDs are advertised to have drastically higher watts than they actually use. So when testing 250w HPS vs a 230w LED panel for example, the HPS may actually be using 350 watts while the LED may be using 150 watts. Then with LEDs some of the wattage comes from the fans inside so using a watt meter still doesn't directly tell how much wattage of electricity is being used to light the LEDs

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If your 250w HID is using 350w you better get something checked out, looks to be dangerous!

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Correct me if I'm wrong but dosent a ballast use roughly 10% of the power that goes to the bulb? That's how I was told, a 600w ballast uses 60w, 1000 uses 100w. I think he (the guy who told me this) uses digital ballasts.

^^^^^yep GOOD ballasts run at the best around 10% But the real crappy fixtures have really inefficient wiring designs(bad capacitors) allowing for large power draws......this also relates to led drivers/floro ballasts/etc.....

The good:
hid---sunpark ballasts(magnetic)---don't know enough about e/digital ballasts
fluoro----fulham racehorse ballast
led-----meanwell driver
induction---LVD ballast

be safe / happy growing

I run 3 apollo 20's they are no where near the 2 1000w HPS lights we had in Cobra hoods, our rooms would hit 85ish during the summer this year our room has been about 70 even during the recent 90 degree weather. thats 900w LED x 3 banks and you can easily touch them during operation. on light rails these are wtf just amazing for small indoor gardens, and even work fairly well for my medium sized one.

Hello.

I've been installing and runner a 120W(90 actual) LED grow light, to replace a 250W HPS(280W actual) in a closet,
the first thing i noted was a dramatic drop in heat and in water evaporation.

Thinking out loud !

This is a blackbody radiation chart, with this we can see how hot something has to be to emit visible light,
looking at the chart I'm guessing that the core of a HPS is between 5000 and 6000°K hot.




Anything that is hot is emitting infrared radiation in the band from 740nm to 3000nm

View attachment 2170962
So anything above 740nm is wasted heat and a 5500°K hot object put out allot of this radiation.

http://en.wikipedia.org/wiki/Infrared
"Much of the energy from the Sun arrives on Earth in the form of infrared radiation.
Sunlight at zenith provides an irradiance of just over 1 kilowatt per square meter at sea level.
Of this energy, 527 watts is infrared radiation, 445 watts is visible light, and 32 watts is ultraviolet radiation."

So this is the numbers for a perfect blackbody radiation source.

Hot sodium gas i guess is not emitting in a perfect blackbody spectrum but has it own spectral lines.


I think this is what is behind the HPS's spectrum, but in the most charts we see, the real IR radiation is not shown.

On this chart witch goes a bit into the IR, some small peaks are visible, and it look like it could increase in the lower area.



So a 600W HPS puts out 300 Watts of heat if it was a efficient nuclear furness, but it's not instead we use moving
electrons to create friction and heat. So i would not be chocked to find out that a 600W HPS puts out 100W of IR and 80 watts of visible light.

Going even further with that 80 watts of visible light, and think about what can a plant use of that 50% 40 watts maybe.

600W of electricity becomes 80 watts of light.

http://en.wikipedia.org/wiki/Thermal_management_of_high-power_LEDs
"Most of the electricity in an LED becomes heat rather than light (about 70% heat and 30% light)."

So using a 600W LED we should get 180 watts of light, furthermore the spectrum of the LED can be
pinpointed to the right spectrum with absolutely no wasted green light.


Rass.

^^^ Not bad for a first post

thatsmessedup> Thanks, I think.

"looking at the chart I'm guessing that the core of a HPS is between 5000 and 6000°K hot."

Looks like I was way to hot there, on this chart HPS is only 2200° Kelvin
but that just moves the peak down further to infrared as shown on the first image, in the post above.

Here is the spectrum of the HPS lamp. with a wider spectrum than the other image, but not all the way to 3000nm,
but there is a IR spike at approx 825nm.


Source: Industrial (white) lighting company
http://www.arklighting.co/?comparison-of-led-v-other-light-sources-including-hid,207

Another one:


Source: Taiwanese agriculture site
http://flora.coa.gov.tw/view_eng.php?id=92

I started with a little ProSource 90w UFO, and eventually wound up with 2 big 180W Jumbos from the same company. I can't say enough about these lights after 4 successive grows with tight bud densities and some donkey dicks as long as my arm. Lots of popcorn around the plant bottoms but that happens with a friend's HID's. I did run into a strain however (Dynafem Sweet Deep Grapefruit) that once put in flower under these LED's showed signs of excessive stretching and outgrew my lights hanging capacity in a 7' tent in just 3weeks flower. The leaves would point almost straight up to the LED's...so weird. I really wanted this strain so I pulled clones, chopped and bought a 400W digital ballast setup with 250w & 400w capacity to repeat the grow. In veg with a MH the heat wasn't too bad to control with my exhaust fan speed only a little higher than what the 2 - 180WLED's needed. But once I switched to HPS the heat came up brothers and I had to start cranking on the speed control to keep the tent under 88°. As a matter of fact I ran the 250W setting for a couple of days wondering if I would ever do the 400W setting again. Not just the tent ran hot...the ballast on a wire rack outside the tent was clocking 130° case temperature on an IR temperature gun. Now my room is running warmer too. The strain in behaving though....28" and 1 week of flower so far. No leaves pointing upward either. In comparison the LED's exhaust from the side of the housing but are easy to maintain with a 160CFM exhaust fan on a speed controller set to it's lowest setting. Even though the HPS is in a closed vented hood as a part of the exhaust system...it needs the controller set to at least 60%. The radiant heat on the tent side is noticeable too. It's been a fun comparison thus far...very interesting are the limitations of both. Can't wait to see the buds on these lights (digilux lamp/lumatek ballast)

From my personal experience I had 4 Blackstar 600's actual 340w each in my flower room 7x15. I run a passive air room pulling in fresh air through a furnace filter fitted into the wall via a 8" 745CFM fan with large carbon filter. My temps then were 81-85f lights on. I ended up selling the lights 3 of them to a friend and I kept one for my veg room. I replace them with 2 1000w HPS digital baddass ballast and bulbs in 8" blockbuster hoods. (carbon scrubber - hood-hood-fan-exit). My system consistantly runs 74-77f lights on, during winter monthes I can keep it at 68-70 if I run the fan wide open. That;s just my personal experience with led and hps and the results I got. I thought for sure I was going to have to add A/C the the HPS set up.

jela10 said:

I started with a little ProSource 90w UFO, and eventually wound up with 2 big 180W Jumbos from the same company. I can't say enough about these lights after 4 successive grows with tight bud densities and some donkey dicks as long as my arm. Lots of popcorn around the plant bottoms but that happens with a friend's HID's. I did run into a strain however (Dynafem Sweet Deep Grapefruit) that once put in flower under these LED's showed signs of excessive stretching and outgrew my lights hanging capacity in a 7' tent in just 3weeks flower. The leaves would point almost straight up to the LED's...so weird. I really wanted this strain so I pulled clones, chopped and bought a 400W digital ballast setup with 250w & 400w capacity to repeat the grow. In veg with a MH the heat wasn't too bad to control with my exhaust fan speed only a little higher than what the 2 - 180WLED's needed. But once I switched to HPS the heat came up brothers and I had to start cranking on the speed control to keep the tent under 88°. As a matter of fact I ran the 250W setting for a couple of days wondering if I would ever do the 400W setting again. Not just the tent ran hot...the ballast on a wire rack outside the tent was clocking 130° case temperature on an IR temperature gun. Now my room is running warmer too. The strain in behaving though....28" and 1 week of flower so far. No leaves pointing upward either. In comparison the LED's exhaust from the side of the housing but are easy to maintain with a 160CFM exhaust fan on a speed controller set to it's lowest setting. Even though the HPS is in a closed vented hood as a part of the exhaust system...it needs the controller set to at least 60%. The radiant heat on the tent side is noticeable too. It's been a fun comparison thus far...very interesting are the limitations of both. Can't wait to see the buds on these lights (digilux lamp/lumatek ballast)

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This is very good info.. Thanks +rep