thatsmessedup
Well-Known Member
Its probably because leds just through the heat everywhere. Your hps hoods direct the heat out. Very good info as well +rep
LED heat VS HPS heat?
- Thread starter thatsmessedup
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dbkick
Well-Known Member
I'm running about 640 actual watts of blackstar 500 in a 4 by 4 tent, I'm using nothing but a 6 inch inline fan (cheap kind) , I gotta keep temps outside the tent as low as possible without AC but my tent never exceeds 80 F (which is still a little high ) . now if I had a 600 watt hps I think my temps would probably be MUCH higher. LED do dissipate heat in a different way than hps.
dbkick
Well-Known Member
I should have gone on to say I have a 1kw hps doing a comparison of two plants in each room, its been back and forth but even though I know the hps is gonna kill the led I don't really think the led will do too bad. plus this being my first led grow I've made errors. I think this next run I'll do 3 bs 500 on one cherry ak47 plant I've vegged up fairly large.
THEFAT
Member
I know this sounds weird but i ran a 90w ufo along with some cfls in my cabinet and my temps were up around 83,Now i have since then switched all those lights out for a 250w hps and my temps now run 75..so it all depends how you have it vented
thatsmessedup
Well-Known Member
^^ Interesting. I think CFLs are a lot hotter then people realize.
bassclef
Active Member
LEDs are not very hot directly under the light and generally don't heat up a room very much.
They radiate heat upwards into a heatsink, which gets blown out of the fixture and circulated around the room. They do get hot if they are run with a higher current than they are rated for (and most do) so whatever paltry heatsinks most companies use get pretty damn hot. Hotter heatsink=reduced light output and lifespan. A well designed heatsink will not get much above 100F (warm to the touch) and the LEDs will be more efficient with more energy going to light rather than heat.
They radiate heat upwards into a heatsink, which gets blown out of the fixture and circulated around the room. They do get hot if they are run with a higher current than they are rated for (and most do) so whatever paltry heatsinks most companies use get pretty damn hot. Hotter heatsink=reduced light output and lifespan. A well designed heatsink will not get much above 100F (warm to the touch) and the LEDs will be more efficient with more energy going to light rather than heat.
jela10
Well-Known Member
I love how I can tease my plants with only small light height increases during that first 3 weeks of flowering "stretch". I would come home and some of the tops would be up against the LED glass shield and curled over. Not even burned....I just raise'em a little higher the next day and they go back to straight up....I could never do that with my HPS....I did get a white tip every now and then on the very tip of a cola with LED's being to close....no problem....makes interesting conversation for friends though, even made up some cool lies about the origin (LOL).
Oscar Zeta Acosta
Active Member
Did someone just used the word LED and heat in the same sentence?
smppro
Well-Known Member
I dont understand where people are getting heat from, ive used a 400hps, 150hps, around 350cfls, and 252w led. I can say the 150hps is hotter than the 252led. The hps and cfls both put off heat that needs to be dealt with, i know people like to say watt for watt but from my experience hps>cfl>led. The last time i used my leds i just threw them in a closet with no exhaust and they got only a few degrees above room temperature, it was weird every time i opened the door, just bright lights, barely any noise, no heat, and growing plants, all the way up to the lights. To compare i just had the 150hps in my kitchen over an aquaponic setup and you could feel the heat when you stood next to it, plus you dont want the plants getting close to that. Just my 2cents
Forgive me for reviving a 8 year old thread but... wanted to get this question answered. There are so many different answers and since 8 years have passed, I'm wondering if the opinion has changed or results have gotten better?
I'm trying to plan for a indoor grow and sizing my AC properly. Apparently the lights I'm running are 680W's of LED comparable to a 1000W HID. These have a passive heatsink. Would it then be just a straight calculation of 680 x 3.4BTU's per fixture? Comments like the one above make me wonder if the BTU multiple is actually less. Yet, the law of conservation makes me think otherwise. Thoughts?
I'm trying to plan for a indoor grow and sizing my AC properly. Apparently the lights I'm running are 680W's of LED comparable to a 1000W HID. These have a passive heatsink. Would it then be just a straight calculation of 680 x 3.4BTU's per fixture? Comments like the one above make me wonder if the BTU multiple is actually less. Yet, the law of conservation makes me think otherwise. Thoughts?
Airwalker16
Well-Known Member
A/C usage is cut down to about 1/3 of that when using highly efficient LEDs, like samsung LM301B/H, in any given space if it were setup properly with 1000w DEs
Boatguy
Well-Known Member
Watts are watts bud. Leds put out more light per watt, but heat per watt is the same.
Its not radiated the same way, but it is still there
Ok - that's what I figured but was crossing my fingers for a better answer. My AC tonnage will be.... bleh.
Airwalker16
Well-Known Member
I know the since says it's the same, but unsure seems like LEDs are just leaps and bounds, world's ahead in heat management.
Those HID bulbs get 100's of degrees Fahrenheit, just that alone in a tent setting seems impossible to keep on for more than a few minutes before its baking hot. With an LED board with the driver also outside the tent as an HPS ballast usually is, is cool to the touch. Not even comparable.
Those HID bulbs get 100's of degrees Fahrenheit, just that alone in a tent setting seems impossible to keep on for more than a few minutes before its baking hot. With an LED board with the driver also outside the tent as an HPS ballast usually is, is cool to the touch. Not even comparable.
I'm assuming you mean 1/3 of a standard AC load of 1000DE right? not my 680 x 3.4BTU calculation?
Airwalker16
Well-Known Member
No. You will require 1/3-1/2 of what you'd need if you were to use HPS. Documented multiple times over.Ok - that's what I figured but was crossing my fingers for a better answer. My AC tonnage will be.... bleh.
Boatguy
Well-Known Member
1/3 less because its 1/3 less watts
Not 1/3rd less than what you would need for a 600hid
Yes, understood, but that 1/3 reduction is because the input power rating of LED's is less. Meaning a 680W LED is comparable to a 1000W DE regarding PPF - but I'm still using 680W's of energy. My question is addressing the heat produced by the 680 Watts.
Ultimately @Boatguy confirmed that wattage is wattage and the energy needs to go somewhere. From my understanding, a power input of a 680WLED vs a 680W DE HPS will produce the same heat, BUT the 680W LED will produce way more PPF for the plants.
Airwalker16
Well-Known Member
Again, people say watts are watts, but in my mind, it's an 800°F point source of heat 12 hrs a day, VS a 120-180°F point source of heat 12 hrs a day. Lot less heat produced. More so than just the difference in 320 watts less of electricity being used.
kotobide
Well-Known Member
It will put out exactly the same amount of heat