Grow room ambient vs canopy temp

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Streetdoctor3

Member
When talking about grow room temps is it for the canopy or ambient? I’m hearing to run around 86 with co2. Currently running around 80 on my thermostat but the canopy will run around 86-89 when I set my thermostat at around that temp
 
greenersun

greenersun

Well-Known Member
my thermometer has an inside and outside reading with a remote sensor for outside. I mount this on a spike at canopy level. This helps me to know light placement (how high or low). A couple inches can make a difference.
 
Star Dog

Star Dog

Well-Known Member
I set the set the air temperature then adjust the height of lamp for the canopy temperature, basically I'm trying to get the light as close as.

My reasoning for this is that on a sunny day it's 40c+ in the sun but 18/20c in the shade, the met office uses the shade to read temperatures from.
The canopy temperature will vary from middle out, where do you take the reading from?
 
Star Dog

Star Dog

Well-Known Member
I keep my probe in shade so that the radiated heat doesn't affect the reading.
A piece of cardboard tube with a slot cut or half the tube with a slot, like an umbrella.
 
S

Streetdoctor3

Member
Star Dog said:
I keep my probe in shade so that the radiated heat doesn't affect the reading.
A piece of cardboard tube with a slot cut or half the tube with a slot, like an umbrella.
Click to expand...
I set my thermometer on the wood plank that I use to set my net on the canopy in the middle of the room so the light shines on it where the canopy is
 
Star Dog

Star Dog

Well-Known Member
Streetdoctor3 said:
I set my thermometer on the wood plank that I use to set my net on the canopy in the middle of the room so the light shines on it where the canopy is
Click to expand...
By all means it's each to their own.
To me radiated heat and air temperature are two different measurements.
I could lower my or raise my light it's not going to have any effect on the air temperature that is dictated by the fan frequency/time on.

I monitor the canopy temp the air temp and below the screen/net temp they're all relevant.
 
S

Streetdoctor3

Member
Ok
Star Dog said:
By all means it's each to their own.
To me radiated heat and air temperature are two different measurements.
I could lower my or raise my light it's not going to have any effect on the air temperature that is dictated by the fan frequency/time on.

I monitor the canopy temp the air temp and below the screen/net temp they're all relevant.
Click to expand...
Thanks for the feedback greatly appreciated I’m just trying to dial in my grow and wanted to see what people ment by run temps at 85 degrees with co2 that’s why
 
greenersun

greenersun

Well-Known Member
Star Dog said:
I keep my probe in shade so that the radiated heat doesn't affect the reading.
A piece of cardboard tube with a slot cut or half the tube with a slot, like an umbrella.
Click to expand...
I do the same thing keeping the probe in the shade, you get a accurate reading of air temperature. When i was in the dollar store I found a box of those little drink umbrellas. I place it at the top of the spike with the probe directly under it like Star dog does. The creativity is half the fun.
 
Star Dog

Star Dog

Well-Known Member
greenersun said:
I do the same thing keeping the probe in the shade, you get a accurate reading of air temperature. When i was in the dollar store I found a box of those little drink umbrellas. I place it at the top of the spike with the probe directly under it like Star dog does. The creativity is half the fun.
Click to expand...
I like the drinks umbrella idea, I've been meaning to make a nice neat looking shade but never gotten around to it yet, there's always more pressing jobs.
I'll settle for a pack of them umbrellas, perfect!
 
P

PizzaMan5000

Well-Known Member
When I refer to "ambient" I mean the temperature of my house/basement/inlet air. So the differential is between my basement and my tent/cabinet. So if I'm 12 degrees above ambient, and my canopy is 80f, then my basement is therefore 68f ambient.
That's how I look at my rooms. Bonus when my basement is 60f, and I can run more lights without extra fan noise. I could go 20f above ambient and have the same 80f canopy.

I think it's best to measure multiple areas in a room, make sure your roots aren't 55f and your canopy 90f etc. For instance, my basement is 60f right now, but against the wall it's more like 50f.

Edit: plants supposedly don't like 20f differentials between day and night.
 
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Renfro

Renfro

Well-Known Member
As others have stated, an IR thermometer is a valuable tool for spot checks on leaf surface temps. Remember to get close to the leaf, the meter should tell you how wide the area it reads is as the distance increases, some it's right on the meter others it's in the docs but closer equals a smaller point that is sampled.

I picked up an IR camera and have found it to be a valuable tool for me since I consult for many grows. I can easily find areas that aren't getting enough air movement just by looking through the IR camera. It's not something you need for a smaller home grow at all but if you have one for other purposes then you can use it in your grow too.
 
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