Help high temps

Hey guys so I have a tricked out cupboard but having problems with high temps of 29-32c and exhaust fan doesnt seem to be lowering temp at all so im confused and need some help pics attached HELP me get these temps down please also guess I should mention its a 240watt led bulb currently dimmed to 50%15973052204145235317448991440278.jpg
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1.it vents straight out cupboard into room however hot air rises and the intake is very low to ground outside pics 1&2 and goes into grate seen in pic
2.room itself that it vents air from is currently 26.7c while the cupboard itself stays about 29c all the way up to 32C lights on
3.thermometer is right there in pic 3 just behind plant
 

coreywebster

Well-Known Member
Ah right, looked more like a light meter than a thermometer.

First thing is you don't put a thermometer in direct light, especially a black one.
So I would reset the min/max and put it up near your extractor to measure the air temp as it goes out.

26.7c in the room doesn't give you much room for movement though. But first see if you get a better reading out the light.

29c is ideal if you can get it to that consistently your good.

What time do lights come on and off? When's your dark period?
 

HydroKid239

Well-Known Member
the ambient temp is probably affecting your grow space while the lights are on. Not enough cooled air coming thru the intake. I'd say put an AC in the room where the cupboard is to help you.

I noticed that when I turn my AC off the temp and RH rise.
 
Ah right, looked more like a light meter than a thermometer.

First thing is you don't put a thermometer in direct light, especially a black one.
So I would reset the min/max and put it up near your extractor to measure the air temp as it goes out.

26.7c in the room doesn't give you much room for movement though. But first see if you get a better reading out the light.

29c is ideal if you can get it to that consistently your good.

What time do lights come on and off? What time is dark period?
On at 8:15am off at 2:15amWhen's your dark period?dark period is 2:15am till 8:15am on a 18/6 schedule

Where u said 29c is ideal if you can get it to that consistently your good. Does that include in flowering ss I thought it was critical to not go over 26c in flowering
 

coreywebster

Well-Known Member
On at 8:15am off at 2:15amWhen's your dark period?dark period is 2:15am till 8:15am on a 18/6 schedule

Where u said 29c is ideal if you can get it to that consistently your good. Does that include in flowering ss I thought it was critical to not go over 26c in flowering
LED lacks the IR (even ones with IR diodes) of HID so we aim for mid 80s which helps keep leaf surface temps up and thus transpiration and nutrient uptake.
Anywhere from 80-86f is good though 84 is what I would aim for. You will find the same response from anyone who has experience with LED

Like I said though, first thing is to take accurate air temp reading which you cant do in direct light and see if the situation is as bad as you think.
Its the same reason weather stations use a Stephenson screen(painted white), light warms surfaces , especially black ones, throws off the reading.
Big difference between a plants tolerance for radiant heat and air temp.

Other than that a laser thermometer is good for taking leaf surface temps which is really the key to growth
 
LED lacks the IR (even ones with IR diodes) of HID so we aim for mid 80s which helps keep leaf surface temps up and thus transpiration and nutrient uptake.
Anywhere from 80-86f is good though 84 is what I would aim for. You will find the same response from anyone who has experience with LED

Like I said though, first thing is to take accurate air temp reading which you cant do in direct light and see if the situation is as bad as you think.
Its the same reason weather stations use a Stephenson screen(painted white), light warms surfaces , especially black ones, throws off the reading.
Big difference between a plants tolerance for radiant heat and air temp.

Other than that a laser thermometer is good for taking leaf surface temps which is really the key to growth
Alright man ill take them tomorrow(my time) and let u know
 

eyderbuddy

Well-Known Member
My 2 cents:

30C is still OK =]
Make sure you don't reach 35C(95F), that's the trouble zone.

As long as you get your airflow dialed in, and keep your humidity levels below 60% (which is actually a little high for flowering) you should be good.
 
Air vented out temp at night:will update with night temps in few hrs
Day/afternoon:30.8c for full intensity lights
For 50% dimmed lights:29.5c

Temps with theromometer out of light first reading (last night)
Night:27.2c full intensity
Second night reading 28.7c
full intensity
3rd night reading:29.8c
Night temps 50% dimmed:26.4c
Night temps 50%dimmed reading 2: 26.2c

Day time reading temps full intensity before midday :29.3c

Daytime reading temps full intensity reading 2(around midday): 31.9c

Daytime reading temps 50% intensity:23.8c

Daytime reading temps 50% intensity 2: 24.4c

Daytime reading temps 50% intensity test 3 around midday: 27.8c

Afternoon 50% intensity temps after 1pm :27.9c
3pm:28.9



Afternoon temp(after 2pm) full intensity:33c
 
Yeah I plan on getting a dehumidifier when im closer to flowering anyway to be honest atm I'm considering adding more passive intake to help with the heat hopefully with more fresh air the air will be vented out more so that there's more fresh air coming in but will see if anyone has any other ideas first before I go to that measure
 

Cj26

Member
Your best bet is to get that hot air vented out of the room. Or to put a window unit or portable unit in the room the tent is in.
that's great and all but how do I do that and get the hot air vented when ive specifically stated here that it doesn't lower temp when I use my exhaust fan. I used ac in the room it vents from air from last night and had it set to 19c it was still creeping up to 29.4c in there it got as high as dead on 30c. its easier to just say get the hot air out of the room(duh) but how to accomplish that when the exhaust fan doesnt seem to be lowering temp is something entirely different ive tried now with a 4 inch and a 6 inch fan neither seem to do much to keep the heat down/away
 

SheeshM

Well-Known Member
On at 8:15am off at 2:15amWhen's your dark period?dark period is 2:15am till 8:15am on a 18/6 schedule

Where u said 29c is ideal if you can get it to that consistently your good. Does that include in flowering ss I thought it was critical to not go over 26c in flowering
Try running your lights 6 pm to noon in veg so you avoid the hottest part of the day. Then, 6 pm to 6 am in flower. Tweak it an hour or so either way to fit your schedule.
 

1212ham

Well-Known Member
Yeah I plan on getting a dehumidifier when im closer to flowering anyway to be honest atm I'm considering adding more passive intake to help with the heat hopefully with more fresh air the air will be vented out more so that there's more fresh air coming in but will see if anyone has any other ideas first before I go to that measure
A dehumidifier will add heat, you might need an AC instead, or in addition. It looks like more intake area is needed. Does the exhaust seem to give good flow? Does it increase a lot with the cabinet door open? Nice cabinet btw, what are the dimensions?
 
A dehumidifier will add heat, you might need an AC instead, or in addition. It looks like more intake area is needed. Does the exhaust seem to give good flow? Does it increase a lot with the cabinet door open? Nice cabinet btw, what are the dimensions?
Dimensions90(length)x60(width)x160cm(h)
Yeah exhaust is flowing great its a vtronic 6 inch with 2 speed controls lots of negative pressure u can feel it when u try and open the door its that powerful that it sucks the door closed with the door open heats dropping anywhere from 1 degree to 3 degrees depending on what the temps at in there
 
Try running your lights 6 pm to noon in veg so you avoid the hottest part of the day. Then, 6 pm to 6 am in flower. Tweak it an hour or so either way to fit your schedule.
Done set it to run at 6pm-noon(hopefully that works eitherway it should definitely help ) thankyou
 
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