4000w Heat! 120°

kushdaddy1980

Well-Known Member
My growroom is in the garage and im exhausting all my air conditioner heat into attic space above the growroom and out a roof vent with a commecial cooler fan. Im planning on flipping my 8x8 this summer and adding the heat from four 1000w hps cooltubes into that space above my growroom.

I have the exhaust fan hooked into a temperature controller thats set to come on at 85°. It has an alarm feature that beeps when it gets too hot. I have the alarm set at 118° and its steady going off in the hot part of the day.20190629_194633-1.jpg

im thinking of setting it at 120° just to stop the alarming but what if it keeps going off? Does anyone know how hot it can safely get?

Im definitly rerouting the a/c exhaust to go outside somehow. My concern is when is when i flip the 4000w lights on and pump all that heat into the garage.

I have to come up with some kind of better ventilation for this attic space because the cooler fan isnt cutting it. for now ive been opening the garage door and put a desk fan up top to try and get some cooler air in from outside. I really dont like doing this though as my grow is more exposed with the door open.20190629_194651.jpg

i saw a 500cfm solar powered exhaust fan for $40 bucks (retail $159) does anyone have experience with these type of exhaust fans? Would that even phase my kind of heat issue?

the plants inside the room are doing great, it stays about 85 at plant level. Its a little cooler outside the tents.i have the a/c set at 68°F and its crankin 24 /7.

The issue is how hot its getting above the growroom. Am i risking fire at a certain temperature? What is the risk at 120°? And how to ventilate all that heat properly without adding an additional a/c unit.
 

Renfro

Well-Known Member
It's not going to get hot enough to start a fire, not even close. You would need to be around 450 degrees to start wood combustion.

Why not just exhaust the AC heat outside instead of the attic?

or get a minisplit and not have to worry about it at all?
 

kushdaddy1980

Well-Known Member
It's not going to get hot enough to start a fire, not even close. You would need to be around 450 degrees to start wood combustion.

Why not just exhaust the AC heat outside instead of the attic?

or get a minisplit and not have to worry about it at all?
Another issue is there are no windows on this building, and im trying to keep the operation covert as possible. im running the a/c exhaust out the bottom of the garage door at the moment.that has lowered the temps a bit but when i start flowering and turn on my lights its going to produce just as much heat as 4 thousand watt heaters.
im leaning towards installing some roof vents and exhausting each light bank through the roof. It will be a lot of work but maybe that would work better if i just keep the extra heat out altogether.
Mini split is way out of my budget, i have about 50 bucks to my name lol
 
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Renfro

Well-Known Member
Well you could use a roof vent for the AC exhaust maybe? I duno how much that would cost to do right. When you are flowering definitely run at night lol. I wish I had a magic solution.
 

kushdaddy1980

Well-Known Member
Well you could use a roof vent for the AC exhaust maybe? I duno how much that would cost to do right. When you are flowering definitely run at night lol. I wish I had a magic solution.
yeah im definitly running the lights at night, and i can get roof vents for 20 bucks each and i can do the work myself. Thats probably what ill end up doing
 

hotrodharley

Well-Known Member
Can you see the main plumbing vent to the roof? Usually large and black. It will be above the kitchen bathroom area. Black PVC pipe if that needs to be said.
 

thumper60

Well-Known Member
My growroom is in the garage and im exhausting all my air conditioner heat into attic space above the growroom and out a roof vent with a commecial cooler fan. Im planning on flipping my 8x8 this summer and adding the heat from four 1000w hps cooltubes into that space above my growroom.

I have the exhaust fan hooked into a temperature controller thats set to come on at 85°. It has an alarm feature that beeps when it gets too hot. I have the alarm set at 118° and its steady going off in the hot part of the day.View attachment 4357736

im thinking of setting it at 120° just to stop the alarming but what if it keeps going off? Does anyone know how hot it can safely get?

Im definitly rerouting the a/c exhaust to go outside somehow. My concern is when is when i flip the 4000w lights on and pump all that heat into the garage.

I have to come up with some kind of better ventilation for this attic space because the cooler fan isnt cutting it. for now ive been opening the garage door and put a desk fan up top to try and get some cooler air in from outside. I really dont like doing this though as my grow is more exposed with the door open.View attachment 4357737

i saw a 500cfm solar powered exhaust fan for $40 bucks (retail $159) does anyone have experience with these type of exhaust fans? Would that even phase my kind of heat issue?

the plants inside the room are doing great, it stays about 85 at plant level. Its a little cooler outside the tents.i have the a/c set at 68°F and its crankin 24 /7.

The issue is how hot its getting above the growroom. Am i risking fire at a certain temperature? What is the risk at 120°? And how to ventilate all that heat properly without adding an additional a/c unit.
can tell u one thing if you live where it below freezing at any time that attic will be full of mold an rot in 6 months rethink ya venting if so:bigjoint:
 

kushdaddy1980

Well-Known Member
Can you see the main plumbing vent to the roof? Usually large and black. It will be above the kitchen bathroom area. Black PVC pipe if that needs to be said.
no, the garage is seperate from the house. Totally worst place to put a grow but its my only option at this time.there is two roof vents 8" i beleive and thats it.
 

oldsilvertip55

Well-Known Member
My growroom is in the garage and im exhausting all my air conditioner heat into attic space above the growroom and out a roof vent with a commecial cooler fan. Im planning on flipping my 8x8 this summer and adding the heat from four 1000w hps cooltubes into that space above my growroom.

I have the exhaust fan hooked into a temperature controller thats set to come on at 85°. It has an alarm feature that beeps when it gets too hot. I have the alarm set at 118° and its steady going off in the hot part of the day.View attachment 4357736

im thinking of setting it at 120° just to stop the alarming but what if it keeps going off? Does anyone know how hot it can safely get?

Im definitly rerouting the a/c exhaust to go outside somehow. My concern is when is when i flip the 4000w lights on and pump all that heat into the garage.

I have to come up with some kind of better ventilation for this attic space because the cooler fan isnt cutting it. for now ive been opening the garage door and put a desk fan up top to try and get some cooler air in from outside. I really dont like doing this though as my grow is more exposed with the door open.View attachment 4357737

i saw a 500cfm solar powered exhaust fan for $40 bucks (retail $159) does anyone have experience with these type of exhaust fans? Would that even phase my kind of heat issue?

the plants inside the room are doing great, it stays about 85 at plant level. Its a little cooler outside the tents.i have the a/c set at 68°F and its crankin 24 /7.

The issue is how hot its getting above the growroom. Am i risking fire at a certain temperature? What is the risk at 120°? And how to ventilate all that heat properly without adding an additional a/c unit.
 

kushdaddy1980

Well-Known Member
looks like a good place to staet with spray foam insulation between rafters then reroute a/c
yeah, thats the crappy part about this is its completely uninsulated up top it lets so much heat through and ive decided when i get the money ill get a roof vent for the a/c as well
 

kushdaddy1980

Well-Known Member
this thing is a beast! Ill be modifying it with a solar charge controller and an AGM battery to run it 24/7 free off the grid! ;)20190630_202023.jpg
 

Apalchen

Well-Known Member
I dunno man I can't work in my attic during the day it's unbearable and that's without venting anything into it. And that's my house attic. I think it's safe to say that many attics are 120 degrees or hotter during the summer days. But if that's without the lights I would shop around for a big exhaust fan, I see big metal exhaust fans on the gables of roofs that have metal slats that close when your not using it. I'd look around at second hand stores or online market place yard sale type websites and see if could find a used one. I see a lot of them on barns and green houses and dont think it would look out of place on a garage.
 

cindysid

Well-Known Member
I would go with fewer lights. At that temp range you are going to produce a crappy product. I would run 2 1000 watt lights in a 5 x 10 space. You'll produce just as much or more than you will in extreme heat. IMO you're wasting your time trying to grow in that kind of heat. You can expand your grow when the weather is cooler.
 

Apalchen

Well-Known Member
I would go with fewer lights. At that temp range you are going to produce a crappy product. I would run 2 1000 watt lights in a 5 x 10 space. You'll produce just as much or more than you will in extreme heat. IMO you're wasting your time trying to grow in that kind of heat. You can expand your grow when the weather is cooler.
I think you misread the original post his grow room is only like 86 which is fine, he was worried about how hot his attic is getting.
 
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