LED heat output for large LED grow?

kerdiggz

kerdiggz

Active Member
Hey there... I'm in the planning stages of a new grow and just wanted some input. I've always used HPS to grow, but for the new grow I'm considering trying LED.

Looking to start a 8-10K grow. But using HPS I will need a mini-split ac that will likely cost $4-5K. I would like to avoid that if possible.

Now I know that air cooled 1K HPS needs around 4000 btu of cooling each. My question is does anyone know what the heat output in btu is for a 1K LED or 1200w LED?
 
ttystikk

ttystikk

Well-Known Member
If it's pulling that much wattage from the wall, then one way or another you'll be dealing with the heat. LED may skew things towards light output, for example, but then the plants will be transpiring more and so you'll need more dehuey.

Don't skimp on the environmental control. Just trust us old growers on this one. You'll thank me later...
 
bicit

bicit

Well-Known Member
The amount of heat output by a 1kw hps bulb will be identical to a 1kw LED. Heat and power displacement are the same thing. Make sure you enter in ALL equipment drawing power(pumps, computers, access lighting, cell phone charger, ect) when sizing your AC system. For every watt of power you consume you need 3.5-4 btu of cooling potential.
 
CanadianONE

CanadianONE

Well-Known Member
LED convert more energy to light compared to HPS therefore less heat is produced. With that said I don't think you can totally remove the cooling factore with that many watts running you will still need some cooling. Just my opinion.
 
CanadianONE

CanadianONE

Well-Known Member
Heat output for 1000w LED vs HPS will not be the same. From my understanding LED is more efficient therefore translates more of that 1000w power into light over the HPS which then means less heat. That's my opinion from everything that I have been reading. If I am wrong someone correct me ;)
 
bicit

bicit

Well-Known Member
CanadianONE said:
Heat output for 1000w LED vs HPS will not be the same. From my understanding LED is more efficient therefore translates more of that 1000w power into light over the HPS which then means less heat. That's my opinion from everything that I have been reading. If I am wrong someone correct me ;)
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Heat is(or rather, a form of) energy. Energy is always conserved. Light is also a form of energy emitted in discrete packets. These discrete packets, or photons, bounce around the room transferring their energy into everything it interacts with until it is finally absorbed. Yes even the light(energy) absorbed by the plants ultimately wind up as heat through losses in the biological functions as heat. Further reading

The advantage to using LED's is using less power to maintain a given photon density. Or in other words, if you need 1kw to produce 1300ppfd over a 4x4 canopy with a 40% efficient HID. Then you can use 650w to produce the same photon density using 60% efficient LED's. Thereby reducing the overall heatload on the HVAC system.

Yes HID bulbs operate at a much higher temperature to facilitate it's reaction. How ever that's not the same metric as measuring heat transfer into and out of a system. Which is what you want to measure when considering HVAC systems.
 
CanadianONE

CanadianONE

Well-Known Member
bicit said:
Heat is(or rather, a form of) energy. Energy is always conserved. Light is also a form of energy emitted in discrete packets. These discrete packets, or photons, bounce around the room transferring their energy into everything it interacts with until it is finally absorbed. Yes even the light(energy) absorbed by the plants ultimately wind up as heat through losses in the biological functions as heat. Further reading

The advantage to using LED's is using less power to maintain a given photon density. Or in other words, if you need 1kw to produce 1300ppfd over a 4x4 canopy with a 40% efficient HID. Then you can use 650w to produce the same photon density using 60% efficient LED's. Thereby reducing the overall heatload on the HVAC system.

Yes HID bulbs operate at a much higher temperature to facilitate it's reaction. How ever that's not the same metric as measuring heat transfer into and out of a system. Which is what you want to measure when considering HVAC systems.
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@bicit Thanks for the extra bit of knowledge. I am learning everyday on RIU it's great. I do my part to try and input as much as I possibly can but its great when someone with a little more knowledge on the subject can confirm or deny my advice. I learn in the process also which is a bonus. So to replace a 1000w HID with 1000w LED you still end up with the same heat but with that said you could replace the 1000w HID with 650w LED to retain same photon density which would save on cooling cost and electrical bill. I am starting to grasp the concepts of LED. Very knew to the high power LED's (COBS) Thanks again
 
dandyrandy

dandyrandy

Well-Known Member
Or you can make a cooltube led. 800w in a 46" x40" area with around 70 cfm of air total through the tubes allows a 5° rise 4" or so below the LEDs. I run at ~500w though. I don't need that much light. I see 3° rise at 500w.
 

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CanadianONE

CanadianONE

Well-Known Member
dandyrandy said:
Or you can make a cooltube led. 800w in a 46" x40" area with around 70 cfm of air total through the tubes allows a 5° rise 4" or so below the LEDs. I run at ~500w though. I don't need that much light. I see 3° rise at 500w.
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Do you have a build log for that beast? I would like to see more pictures of it. Is that made with PVC post cover?
 
bicit

bicit

Well-Known Member
CanadianONE said:
@bicit Thanks for the extra bit of knowledge. I am learning everyday on RIU it's great. I do my part to try and input as much as I possibly can but its great when someone with a little more knowledge on the subject can confirm or deny my advice. I learn in the process also which is a bonus. So to replace a 1000w HID with 1000w LED you still end up with the same heat but with that said you could replace the 1000w HID with 650w LED to retain same photon density which would save on cooling cost and electrical bill. I am starting to grasp the concepts of LED. Very knew to the high power LED's (COBS) Thanks again
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Yup, just remember that anything that uses electricity is going to contribute to the heat load. Yes, that includes fans both oscillating and extraction. Even the biological functions of microbes in organic soil, thermometers, and anything that moves adds heat to the system.

Rrog said:
COBS = BORG

They are the inescapable future
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CanadianONE said:
@Rrog BORG?
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CanadianONE

CanadianONE

Well-Known Member
bicit said:
Yup, just remember that anything that uses electricity is going to contribute to the heat load. Yes, that includes fans both oscillating and extraction. Even the biological functions of microbes in organic soil, thermometers, and anything that moves adds heat to the system.





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With a quick google search this was the conclusion I had come to lol. Never was a big Star Trek fan. Thanks for the clarification.
 
dandyrandy

dandyrandy

Well-Known Member
CanadianONE said:
Do you have a build log for that beast? I would like to see more pictures of it. Is that made with PVC post cover?
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5" post. I used angle aluminum in the corners but not needed. 4 vero 29's per bar. Bar 46" long. 2 bars in the area. 4" blower 6" inline carbon filter. Y above the bars. Sail switch mounted in y. No air no power to LEDs. I used a hole saw in the top above each cob fan.
 

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kerdiggz

kerdiggz

Active Member
@bicit thanks for all the info much appreciated. That bit of info is exactly what I was after. It's great to learn from the knowledge and experience of others.

So just one question, if you said that for every watt of power you consume you need 3.5-4 btu of cooling... then a 1000 w led that only consumes say 475w should really need about 1900 btu of cooling?

@CanadianONE thanks for the input, and I'm glad we can both learn about all of this together

@dandyrandy wow that's the first I've heard about a cool tube for leds. Sounds like something I have to look into. Thanks

@Rrog hey maybe my wife can do the same for me... haha
 
dandyrandy

dandyrandy

Well-Known Member
Rrog said:
Supra built me a COB system with remote ballasts for heat control. They rock. I have my wife strut around with them while naked. I can't help it, however it's helped our marriage
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I should have had my wife done that before I mounted them inside the fence post.
 
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