CFL closet grow - considering LED

PizzaMan5000

Well-Known Member
If want to read air temperature it is a simple affair, can't follow your complicated approach.
I think it's best to make sure there aren't hot and cold spots in the room. Even with the turbulence of my led's internal fans, and an oscillating fan I know my colas are running warmer than the shady parts of the plant. Leaf temperature matters too.
I feel like most people verify temperature from multiple points to be safe. I could have 74 degree exhaust temps, and have my colas smoking theoretically....
 
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BBQtoast

Well-Known Member
A 135watt HLG QB will destroy the 200watt cfl in terms of light output, and will be cooler due to lower wattage.

Both ambient temps and also leaf surface temps are important.

View attachment 4804819
If the leaf is in the right conditions you wouldn't check it and see that it fluctuates across and with depth.

Reading and setting the right air temperature is all you need, most are not delving into deeper topics just measuring the air and making that right for species.

Leaf is light driven, air is not in fact air finds it hard to capture and absorb photons which is why it's cooler than the leaf, that difference is the start to transpiration measurements. Transpiration is a system with other inputs and outputs we need to read.

Complicated, owning infrared doesn't mean you did the biology.
 

PJ Diaz

Well-Known Member
If the leaf is in the right conditions you wouldn't check it and see that it fluctuates across and with depth.

Reading and setting the right air temperature is all you need, most are not delving into deeper topics just measuring the air and making that right for species.

Leaf is light driven, air is not in fact air finds it hard to capture and absorb photons which is why it's cooler than the leaf, that difference is the start to transpiration measurements. Transpiration is a system with other inputs and outputs we need to read.

Complicated, owning infrared doesn't mean you did the biology.
Different light sources will heat leaf surfaces differently. It's important to know how your specific light is interacting with the plant. I grow with both HPS and LED, depending on the situation, and the different light sources have a profound impact on the plant temps, mainly because of the huge IR spike around 820nm from HID lamps, which is directed towards the plants.
 

PizzaMan5000

Well-Known Member
Gotta remember that like a cfl, the led's won't be in a vented hood so all the heat is staying in the room. So it's not just infared heat, it's also radiant heat from the equipment.

So 1000w of led heat would require more air transfer for the tent, as opposed to having a vented hood on a separate fan from the room air.

That's the catch with LED's, they aren't in vented hoods....
 

BBQtoast

Well-Known Member
Different light sources will heat leaf surfaces differently. It's important to know how your specific light is interacting with the plant. I grow with both HPS and LED, depending on the situation, and the different light sources have a profound impact on the plant temps, mainly because of the huge IR spike around 820nm from HID lamps, which is directed towards the plants.
Leaf temperature is back to water use, I think we need some water sensor somewhere to make sense of the leaf temperature reading.

Need to check this sometime.
 

BBQtoast

Well-Known Member
Gotta remember that like a cfl, the led's won't be in a vented hood so all the heat is staying in the room. So it's not just infared heat, it's also radiant heat from the equipment.

So 1000w of led heat would require more air transfer for the tent, as opposed to having a vented hood on a separate fan from the room air.

That's the catch with LED's, they aren't in vented hoods....
Vented only cools the bulb and reflector. Like 90% of the heat is the light hitting the leaves and tent.
 

PJ Diaz

Well-Known Member
Leaf temperature is back to water use, I think we need some water sensor somewhere to make sense of the leaf temperature reading.

Need to check this sometime.
Growers such as Josh Neulinger do exactly that, which is the foundation for their "crop steering" data. He measures light, ph, rh, EC, soil moisture, temps, etc, and charts them all in an app:
Screenshot (17).png

His results speak for themselves:

Screenshot (18).png

Screenshot (19).png
 

Tonycannavis

Well-Known Member
Best budget LED I recommend to my friends growing stealth for a small grow easier to keep the environment temperature and humidity just enough heat to keep the box temperature dial Spider farmer and sf 1000 D no dimmer but who needs a dimmer on a 1000 Pulling 96 watts from the wall 2x2 cabinet all I have two small AC infinity cabinet fans. Hope this helps
 

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PJ Diaz

Well-Known Member
Best budget LED I recommend to my friends growing stealth for a small grow easier to keep the environment temperature and humidity just enough heat to keep the box temperature dial Spider farmer and sf 1000 D no dimmer but who needs a dimmer on a 1000 Pulling 96 watts from the wall 2x2 cabinet all I have two small AC infinity cabinet fans. Hope this helps
This light is far superior to a sf1000, and is only $10 after you use the RIU10 code: https://horticulturelightinggroup.com/collections/kits/products/135w-qb-v2-rspec-led-kit
 

PadawanWarrior

Well-Known Member
Great idea with the HLG light, if the driver is outside the closet there should be less heat inside. I guess I could also put small fans on top to lower the heat if needed

Anyone know if this works with 220v electricity? (EU) From the looks of it it seems to be american plug. I don't know much about electricity and difference between 120v and 220v, can I just switch plugs?

Also, smell is not an issue and my thermometer is about the same length from the light as the canopy

Edit: HLG doesn't ship to my country
Sure they do.

Best LED Grow Lights UK & Europe | HLG LED No1 in UK Europe (hlg-uk-europe.com)
 

Bookush34

Well-Known Member
If you don’t have a exhaust fan you are definitely going to want something with a remote driver.

I habe a 20”x36”62” veg area with 200 watts of cobs in it. Need a 4” inline exhaust to control it.
But I bet with the door open you would be fine.
 

PJ Diaz

Well-Known Member
Some sort of exhaust fan is a necessity. Otherwise, how will you get fresh air to the plants?
 
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