Overheating in Tent

H

High Tide

Well-Known Member
Hi.....need advise from everyone.......i live in a high humidity environment 80RH which made mildew and rot a problem......I got a 4x8 grow tent to flower in hope of a controlled environment in my enclosed garage......a dehumidifier was the only way to get acceptable humidity........humidity is great now steady mid 40's......but the temperature according to my device is 88-91 degrees......yikes.............i have 2 LED lights with a 6" hyperfan pulling through a carbon filter at full speed.........my intake vents are 4 3" x 18" mesh screen on 3 sides.....i got all of them open.........should i open other 8" optional duct holes on upper side walls..........i need to lower the temperature, but don't quite know what to do......thank you for all of your help.......

does anyone else have these issues.....sure would like to know the answer..........
 
nomofatum

nomofatum

Well-Known Member
Where is your exhaust going? It should be leaving the garage unless you are going to use CO2 and A/C.
Make sure your thermometer is out of the "sun" or it will read incorrectly. I gave up on weatherstations and now use my laser thermometer to spot check. Always take temps in the shade, I just block the light with my hands and use the laser thermometer now.
 
N

noodleman

Active Member
I had an apparent heat problem with about 800 W of LEDs in a 4X2 ft. tent - temps in upper 80's to low 90's. Then I realized I had my temperature sensor well above the canopy and too close to the lamps' exhaust fans from which most of the LED heat exits. I lowered the temperature sensor to the height of the canopy and temperatures there were in the upper 70's to low 80's. My understanding is that LEDs do not emit much radiative heat so as long as you can keep the lamp height about 16" or more above the canopy most of the LED heat will be go out the lamp exhaust and be directly sucked up into the carbon filter by the tent's exhaust fan without excessively heating the lower part of the tent. At least this worked for me.
 
orbo

orbo

Well-Known Member
Make sure you hoist that carbon filter up to the top of the tent to pull that hot air out from up high. Also, it would be good if the mesh openings you speak of are at the bottom of your tent. This allows the cool air to flow through the vegetation. Be mindful of root zone temps at night if you do bring the air in from the bottom.

EDIT: Also, what size in the carbon filter and - as @noodleman has asked - where are you pulling your readings from?
 
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H

High Tide

Well-Known Member
noodleman said:
I had an apparent heat problem with about 800 W of LEDs in a 4X2 ft. tent - temps in upper 80's to low 90's. Then I realized I had my temperature sensor well above the canopy and too close to the lamps' exhaust fans from which most of the LED heat exits. I lowered the temperature sensor to the height of the canopy and temperatures there were in the upper 70's to low 80's. My understanding is that LEDs do not emit much radiative heat so as long as you can keep the lamp height about 16" or more above the canopy most of the LED heat will be go out the lamp exhaust and be directly sucked up into the carbon filter by the tent's exhaust fan without excessively heating the lower part of the tent. At least this worked for me.[/QUOT

excellent info........checked and my sensor is at mid canopy level.........numbers i think are pretty accurate......
Click to expand...
 
H

High Tide

Well-Known Member
orbo said:
Make sure you hoist that carbon filter up to the top of the tent to pull that hot air out from up high. Also, it would be good if the mesh openings you speak of are at the bottom of your tent. This allows the cool air to flow through the vegetation. Be mindful of root zone temps at night if you do bring the air in from the bottom.

EDIT: Also, what size in the carbon filter and - as @noodleman has asked - where are you pulling your readings from?
Click to expand...
fan is at the top........filter is a phresh 500 i think.....it is 24: long.............the mesh intake slots are 6" from the floor level and about 20" long.........they are on 3 walls and i have them all open............i have currently vented out dehumidified dry air and it helped a bit bringing temp to 81.....
 
Purpsmagurps

Purpsmagurps

Well-Known Member
My ducting fell off my fan this morning cause I ran out of duct tape, woke up to it being 97 degrees in my room @ 90%rh, ladies are LOVIN IT, Im glad I caught it within a few hours!
 
orbo

orbo

Well-Known Member
Do you REALLY need the mesh over the openings? It restricts air more than you think.
 
H

High Tide

Well-Known Member
orbo said:
Do you REALLY need the mesh over the openings? It restricts air more than you think.
Click to expand...
you're right it definitely restricts air.....buut if you don't have it there is a risk of infesting bugs finding their way in....which would be disastrous
 
orbo

orbo

Well-Known Member
High Tide said:
you're right it definitely restricts air.....buut if you don't have it there is a risk of infesting bugs finding their way in....which would be disastrous
Click to expand...
I thought you said it was a controlled env - the garage? I keep my tent in the garage too and leave the door wide open during the day almost every day. Spiders, stink bugs, centipedes...all kinds of critters go in there. Sometimes, they might eat a little bit before I spot the harmful ones and snatch 'em up. I suppose if I never cleaned it out and always kept it loaded with plants the bugs would breed and make little stink bug babies and in 12,14,16 weeks (whatever it is) it might be a problem. But I always clean everything between grows so no breeding gestating making baby critters remain. And I reuse and amend my soil in such a way that no bugs survive so the soil is cool for next grow. And the plants that get harvested are trimmed and closely examined so no major castaways are going into my curing jars. I guess my point is, so what if a few bugs get in? You need more air.

I live in PA where there really aren't many bugs in the winter so I can get away with it. Do you live in an environment that truly warrants such extreme counter-measures? If so, then I get it and just disregard my rant above. My advice would be to open every exhaust vent that tent has - covering with mesh to ensure no disasters - and see where the temps level off. From there you have few options. More cool air in and/or more hot air out by whatever means. Hope I didn't bore you. I had a few drinks tonight!!
 
H

High Tide

Well-Known Member
appreciat
orbo said:
I thought you said it was a controlled env - the garage? I keep my tent in the garage too and leave the door wide open during the day almost every day. Spiders, stink bugs, centipedes...all kinds of critters go in there. Sometimes, they might eat a little bit before I spot the harmful ones and snatch 'em up. I suppose if I never cleaned it out and always kept it loaded with plants the bugs would breed and make little stink bug babies and in 12,14,16 weeks (whatever it is) it might be a problem. But I always clean everything between grows so no breeding gestating making baby critters remain. And I reuse and amend my soil in such a way that no bugs survive so the soil is cool for next grow. And the plants that get harvested are trimmed and closely examined so no major castaways are going into my curing jars. I guess my point is, so what if a few bugs get in? You need more air.

I live in PA where there really aren't many bugs in the winter so I can get away with it. Do you live in an environment that truly warrants such extreme counter-measures? If so, then I get it and just disregard my rant above. My advice would be to open every exhaust vent that tent has - covering with mesh to ensure no disasters - and see where the temps level off. From there you have few options. More cool air in and/or more hot air out by whatever means. Hope I didn't bore you. I had a few drinks tonight!!
Click to expand...
i appreciate the advice.......i live in the south pacific where it is like the amazon rain forrest.....high humidity hot most of the time......mildew/mold love it here........
....i feel like air is not evacuating fast enough through my fan/filter.....which is a 6" hyperfan and 24" phresh carbon filter....i will open up a few more vents which is all optional exhaust vents and see if that changes things.........current temps are 79-81 .....a lot better but i would like it to be in the 70's..................
 
orbo

orbo

Well-Known Member
High Tide said:
appreciat


i appreciate the advice.......i live in the south pacific where it is like the amazon rain forrest.....high humidity hot most of the time......mildew/mold love it here........
....i feel like air is not evacuating fast enough through my fan/filter.....which is a 6" hyperfan and 24" phresh carbon filter....i will open up a few more vents which is all optional exhaust vents and see if that changes things.........current temps are 79-81 .....a lot better but i would like it to be in the 70's..................
Click to expand...
Oh yeah, you got bugs. Ok...so I hear you on the air evacuation...what about that filter? Do you really need it? Also, with your humidity it might be an issue. You might try pulling it off temporarily to see how it affects your temps? Maybe its plugged or restricting for some other reason. I believe I read its rated at 500 CFM and the fan is 315? That's a decent ratio.
 
blackforest

blackforest

Well-Known Member
What is the temp on the outside of the tent? You can only get the inside within so many degrees of the outside. If air flow is going well, it will be 5 degrees or less higher inside the tent. I have a 4x8 tent running 1800w with a 440cfm 6" fan and a phresh filter. Room temps are 72-74, tent temps are 75-78 and only use the passive intake flaps. I also have a 16" king air in there, a 8" honeywell fan and a vertical 36" fan blowing air on the inside. I noticed when I added more fans on the inside, it did help keep things cooler all around. I can sometimes keep the temps within 1 degree of each other (inside/outside). Also, run your lights at night.
 
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SPLFreak808

SPLFreak808

Well-Known Member
noodleman said:
I had an apparent heat problem with about 800 W of LEDs in a 4X2 ft. tent - temps in upper 80's to low 90's. Then I realized I had my temperature sensor well above the canopy and too close to the lamps' exhaust fans from which most of the LED heat exits. I lowered the temperature sensor to the height of the canopy and temperatures there were in the upper 70's to low 80's. My understanding is that LEDs do not emit much radiative heat so as long as you can keep the lamp height about 16" or more above the canopy most of the LED heat will be go out the lamp exhaust and be directly sucked up into the carbon filter by the tent's exhaust fan without excessively heating the lower part of the tent. At least this worked for me.
Click to expand...
I don't mean to thread jack but, where is the high tide at?
 
A

anzohaze

Well-Known Member
High Tide said:
Hi.....need advise from everyone.......i live in a high humidity environment 80RH which made mildew and rot a problem......I got a 4x8 grow tent to flower in hope of a controlled environment in my enclosed garage......a dehumidifier was the only way to get acceptable humidity........humidity is great now steady mid 40's......but the temperature according to my device is 88-91 degrees......yikes.............i have 2 LED lights with a 6" hyperfan pulling through a carbon filter at full speed.........my intake vents are 4 3" x 18" mesh screen on 3 sides.....i got all of them open.........should i open other 8" optional duct holes on upper side walls..........i need to lower the temperature, but don't quite know what to do......thank you for all of your help.......

does anyone else have these issues.....sure would like to know the answer..........
Click to expand...
Must be a southerner
 
orbo

orbo

Well-Known Member
I think he said S. Pacific - like the amazon rain forest. My assumption was that he knows he wont get it any cooler inside the tent than what is outside the tent. He may just be maxed out without A/C.
 
H

High Tide

Well-Known Member
blackforest said:
What is the temp on the outside of the tent? You can only get the inside within so many degrees of the outside. If air flow is going well, it will be 5 degrees or less higher inside the tent. I have a 4x8 tent running 1800w with a 440cfm 6" fan and a phresh filter. Room temps are 72-74, tent temps are 75-78 and only use the passive intake flaps. I also have a 16" king air in there, a 8" honeywell fan and a vertical 36" fan blowing air on the inside. I noticed when I added more fans on the inside, it did help keep things cooler all around. I can sometimes keep the temps within 1 degree of each other (inside/outside). Also, run your lights at night.
Click to expand...
wow thanks.....super good info........you know i really don't know what my outside tent temp is.....cause i only got 1 sensor sitting inside tent.....but i will need to know that from now........so keeping my inside/outside temps within a few points is what i need to shoot for.......thx again
 
H

High Tide

Well-Known Member
orbo said:
I think he said S. Pacific - like the amazon rain forest. My assumption was that he knows he wont get it any cooler inside the tent than what is outside the tent. He may just be maxed out without A/C.
Click to expand...
the good news is my enclosed garage is 1st floor of a 2 story house....and because it is downstairs on a concrete slab it is cooler than outside house temp which is 80's..........u guys helped me a lot.........i do not want to get an A/C...........u also hit the nail on the head orbo
 
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