help cooling a greenhouse

Merlin34

Well-Known Member
Shade cloth. I work at a huge nursery. Shade cloth goes under the plastic. So we put plastic on in the fall and take it off in spring. The cloth we use on most is like mosquito netting. More for bugs and wind then shade. We do have a couple greenhouses with thicker more light dimming cloth for shade plants. Once you put on the cloth it never needs to come off.

Sent from Northern Colorado.
 

foreverflyhi

Well-Known Member
I agree with others, put a large shade cloth. also, if possible you can dig a trench, and put a false floor to help cool air rise. also, you might want to blow air in the green house for positive intake.

keep in mind cannabis can take over 100+ weather, spray them with aloe and they will be fine!
 

Dr. Treez84

Well-Known Member
Appreciate all the help. Looks like I'll be buying a shade cloth if rolling up the sides doesn't do the trick. One last question, with getting such a late start and having most my plants still under a foot tall. How big of pots should I use? Will they still use a full 100gal or am I better off with 65s

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doublejj

Well-Known Member
You could prob get away with 65's at this point, but 100's would never hurt...have you looked at the greenhouse grows I got going this year?....might be something in there for you...
 

doubletake

Well-Known Member
if your area is hot and dry enough you can put a rudimentary swamp cooler on one end with an industrial fan for moving that cool air down the greenhouse. that's what they do down in pueblo co.

there's even a video showing the set up with some douche from high times.


52.50 starts the look at the swamp cooler.
Hahaha dude are all those quotes on the bottom people have said to you that's fucking funny hahaha
 

veggiegardener

Well-Known Member
You're going to like my advice. I have two greenhouses that regularly reach 130+ during 95+ degree days. The girls LOVE it. The only precaution I take is to keep a fan blowing air OUT of the greenhouse, drawing in cooler air thru ground level vents. Place your young plants at the intake end to benefit from the cooler air. I'd love to have your square feets! Air movement is important, but a tornado is overkill. You need to shade those black pots until you transplant. Keep the soil cool and you'll have no problems.(If I had your set up, and maintained my average per square foot, I'd get over 150 lbs in that space. I'd also have to trim 500 days a year.
 

BrownGuy420

Active Member
Hey bud greenhouses are awesome but a headache to dial in, this is yr3 on growing in GH's and have had to do a lot of reasearch....especially on cooling ur GH. It all really depends on how much u want to spend on cooling. Swamp cooling that beast will be expensive but if you have the funds then by all means do it. But if ur like me and on a budget do the research, I'll try to post a little later for a link to a gh site calculator, you insert your demensions and it will give you a cfm rating minimum. I dont use coolers and am hav i ng no issues with heat. The calc also shows how big for intake holes. You want your intake holes low on one end ( i found 4-5 smaller holes across evenly is better) and the fans on the other end i went about 50% higher on my cfm ratings for a fan so it didnt have to work as hard. You really want to pull air accross the GH pulling in from low and exhauting high. Im doing this and only seeing about a 10-20 degree variance in temps and plants are thriving and growing fast! Good airflow is key. I know i dont have a lot of cred on this site but i do have a following on Youtube...not trying to promote or anything but watch my videos i give a lot of advice on GH growing....once dialed in your GH will explode with growth!
Greenhouse Grow 2014 "Back on Track":

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veggiegardener

Well-Known Member
I strongly suggest avoiding using a swamp cooler. Why? Because they ADD humidity to the air, reducing a plant's ability to cool itself with respiration. My plants do well in high temperatures because air is moving in and out of the greenhouse at a fairly rapid rate. Local humidity(the central valley) is very low throughout the summer. Adding humidity can create conditions favorable to downy mildew during veg, and moldy buds, later in the season.
 

BrownGuy420

Active Member
I strongly suggest avoiding using a swamp cooler. Why? Because they ADD humidity to the air, reducing a plant's ability to cool itself with respiration. My plants do well in high temperatures because air is moving in and out of the greenhouse at a fairly rapid rate. Local humidity(the central valley) is very low throughout the summer. Adding humidity can create conditions favorable to downy mildew during veg, and moldy buds, later in the season.
I agree, unless u have an industrial sized GH just pulling proper amounts of air through the GH will be fine. I agree PM is definitely something to avoid, it's a crop killer!

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BrownGuy420

Active Member
Did you build this GH yourself?
If ur referring to me then yes, its been a long hard stressful road figuring out GH growing but after redesigning mine to where im at now i believe i got it down now. Been in tripple digit weather and the GH is running smooth! She's 18'x20' with 10' ceilings, roll up sides, 30" intake thats pushing 10k cfm's and 4-20" screened intake ports at ground lvl spaced evenly. I can feel air being pulled in from the opposite side from the intakes. I got it wrapped in 6mill 90% transmission UV protected, 4yr agricultural GH plastic. Running 6-65gal smart pots 1/2 way burried in the ground to keep pots cool. Its gotten up to 115 in there but my plants don't skip a beat...just thriving!

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Dr. Treez84

Well-Known Member
Heres that calculator i had mentioned

http://www.littlegreenhouse.com/fan-calc.shtml

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Appreciate the advice. Ordered two exhaust fans that run 7800 cfm each plus the one pushing 4500 now should be enough by that calculator(need around 18500). Definitely gonna check out some of your videos for other ideas to get more airflow coming in. The heat is my last bug to figure out. It's my first year so been a lot of learning curves.

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BrownGuy420

Active Member
Ya my first two seasons were a mad scramble to figure out greenhouse dynamics but i think i got it now, my temps are consistently about 1 degrees above outside temps at max. With such good air flow your plants will be able to handle the heat and flourish. Best to you bro!

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veggiegardener

Well-Known Member
I designed my greenhouses for good ventilation. They are 8' x 12' boxes, with Solexx on three sides and the roof. Vents at ground level on the West, South, and East sides with the Solexx, and roof level vents on the North side. Even without fans, air will move from the intake vents to the exit vents. in 11 seasons, I've never had a problem. Most years, at harvest, the foliage and buds are so dense, I can't even get through the door.
 

BrownGuy420

Active Member
I designed my greenhouses for good ventilation. They are 8' x 12' boxes, with Solexx on three sides and the roof. Vents at ground level on the West, South, and East sides with the Solexx, and roof level vents on the North side. Even without fans, air will move from the intake vents to the exit vents. in 11 seasons, I've never had a problem. Most years, at harvest, the foliage and buds are so dense, I can't even get through the door.
I dream of being there man! GH growin is an art and im sure in 11 seasons you've got it dialed in just right! Would love to see pics of em, im always looking for better ideas to beat the heat, rooftop vents are what i look to do nxt so in them summer days i can let the heat pour right out.

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mhz

Well-Known Member
Hey bud greenhouses are awesome but a headache to dial in, this is yr3 on growing in GH's and have had to do a lot of reasearch....especially on cooling ur GH. It all really depends on how much u want to spend on cooling. Swamp cooling that beast will be expensive but if you have the funds then by all means do it. But if ur like me and on a budget do the research, I'll try to post a little later for a link to a gh site calculator, you insert your demensions and it will give you a cfm rating minimum. I dont use coolers and am hav i ng no issues with heat. The calc also shows how big for intake holes. You want your intake holes low on one end ( i found 4-5 smaller holes across evenly is better) and the fans on the other end i went about 50% higher on my cfm ratings for a fan so it didnt have to work as hard. You really want to pull air accross the GH pulling in from low and exhauting high. Im doing this and only seeing about a 10-20 degree variance in temps and plants are thriving and growing fast! Good airflow is key. I know i dont have a lot of cred on this site but i do have a following on Youtube...not trying to promote or anything but watch my videos i give a lot of advice on GH growing....once dialed in your GH will explode with growth!
Greenhouse Grow 2014 "Back on Track":

Sent from my VS980 4G using Rollitup mobile app
Hey! Brownguy420! Welcome to RIU. I've watched a few of your youtube vids.
 

BrownGuy420

Active Member
Hey! Brownguy420! Welcome to RIU. I've watched a few of your youtube vids.
Haha....whats hapinin! Ya i been on here a while but mainly lurk in the shadows...its cool you've seen my videos...Grow On Brotha!

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