Proper ambient LED temps?? How hot do you run your LED without co2

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Kushizle

Kushizle

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I've recently read that when using LED's the ambient air tempurature should be quite a bit warmer (82-86F) than HPS rooms to acheive the same amount of transpiration. I'm wondering if that applies to all LED brands because the tech has changed so much over the last 10 years. Much of the info I'm reading applies to blurples and older LED's.

My main question is this: Does anyone here run the newer LED's like quantum boards, cobs, bars ect. into the mid 80's without supplementing co2? Did you find an improvment running 85 as opposed to 78?
 
Aqua Man

Aqua Man

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I've recently read that when using LED's the ambient air tempurature should be quite a bit warmer (82-86F) than HPS rooms to acheive the same amount of transpiration. I'm wondering if that applies to all LED brands because the tech has changed so much over the last 10 years. Much of the info I'm reading applies to blurples and older LED's.

My main question is this: Does anyone here run the newer LED's like quantum boards, cobs, bars ect. into the mid 80's without supplementing co2? Did you find an improvment running 85 as opposed to 78?
What matters is leaf temps... not room temps. It will vary from room to room but leaf temps around 77f are the most ideal for photosynthetic rates. You can assume most LED will have temps around 4-10f cooler than ambient depending on the conditions and airflow.

Use a cheap IR gun to check your specific leaf temps and adjust airflow and room temps to attain around 77f leaf temls on an average.
https://www.amazon.com/s?k=ir+temp+gun&ref=nb_sb_noss
 
Kushizle

Kushizle

34
18
I don't have access to amazon or a hardware store for the next 3 weeks unfortunately. Here's what I was reading if anyone is curious. https://news.californialightworks.c...text=LED's emit no IR, so,air temp at 83F-85F.

"78 degrees Fahrenheit (78F) is the widely accepted optimum temperature for most plants at atmospheric CO2 levels (360PPM). This number is actually misleading, because this recommendation is based on tests done with Sunlight or HID lighting, both of which have very high levels of Infrared light (IR)"

"When a leaf absorbs IR, it heats the leaf creating actual leaf temperatures of 5-7 degrees higher than the 78F degree air temperature. Thus with light sources rich in IR, an air temp of 78F is functionally 83F-85F to the plants metabolism. LED’s emit no IR, so to achieve similar metabolic rates found in HID or greenhouse conditions at 78F air temp, LED growers need to run the room air temp at 83F-85F."

Is this info out of date or flat out incorrect?
 
Aqua Man

Aqua Man

26,480
638
I don't have access to amazon or a hardware store for the next 3 weeks unfortunately. Here's what I was reading if anyone is curious. https://news.californialightworks.c...text=LED's emit no IR, so,air temp at 83F-85F.

"78 degrees Fahrenheit (78F) is the widely accepted optimum temperature for most plants at atmospheric CO2 levels (360PPM). This number is actually misleading, because this recommendation is based on tests done with Sunlight or HID lighting, both of which have very high levels of Infrared light (IR)"

"When a leaf absorbs IR, it heats the leaf creating actual leaf temperatures of 5-7 degrees higher than the 78F degree air temperature. Thus with light sources rich in IR, an air temp of 78F is functionally 83F-85F to the plants metabolism. LED’s emit no IR, so to achieve similar metabolic rates found in HID or greenhouse conditions at 78F air temp, LED growers need to run the room air temp at 83F-85F."

Is this info out of date or flat out incorrect?
So here is where everyone fucks up... that 78f they refer to and studies refer to is LEAF temp not ambient temp. With HID typically it will be 0-4f cooler again depending on other factors.

A safe bet for LED is 80-84f. I would say 82f will put most LED growers in the sweet spot. Better just a tad under as once you hit the optimal leaf temp the plant health can decline quickly once you go above that sweet spot.
 

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