Intake and exhaust

my temps vary all day from 75 to 85 Andy’s gotten up to 89 I’d like to keep it mid to high 70s cause I know hotter days are coming soon. my exhaust is a 347 cfm and my intake is forced in and it’s 200 something cfm and the grow room is 5x7. I bought a bigger fan for intake and it’s 400 cfm hopefully it will keep it cooler in there with more fresh air.
What do you guys think?

Whats the ambient temp? Blowing more air wont help much if the ambient temp is warm.

Whatever your intake air is "ambient temp" is the coolest you will get. And that is not counting the heat from lights.

corbin5754 said:

my temps vary all day from 75 to 85 Andy’s gotten up to 89 I’d like to keep it mid to high 70s cause I know hotter days are coming soon. my exhaust is a 347 cfm and my intake is forced in and it’s 200 something cfm and the grow room is 5x7. I bought a bigger fan for intake and it’s 400 cfm hopefully it will keep it cooler in there with more fresh air.
What do you guys think?

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During veg, I've noticed that they like slightly warmer temps (mid 80s), and during flower, from 75 to 80. But, that's not to say that you can't grow with temps out if that range.

One thing you can do during flower, if you can't get your temps to stay down, is to raise your co2 levels. This is really only effective during flowering, but it allows your plants to continue growing with higher temps (90s).

corbin5754 said:

my temps vary all day from 75 to 85 Andy’s gotten up to 89 I’d like to keep it mid to high 70s cause I know hotter days are coming soon. my exhaust is a 347 cfm and my intake is forced in and it’s 200 something cfm and the grow room is 5x7. I bought a bigger fan for intake and it’s 400 cfm hopefully it will keep it cooler in there with more fresh air.
What do you guys think?

Click to expand...

Also, your plants are still going to grow @ 89 degrees. Cannabis will stop growing at 95 degrees (inside). Outside, where there's an abundance of circulation, they can deal with even higher temps. But the inability to replicate outside circulation indoors, 95 is about the limit.

Make sure you have plenty of circulation inside the tent, which is different than intake and exhaust.

I wouldn't wanna push plants at 90+ F unless running supplemental CO2. Yeah they may grow but they will usually make loose, airy, fox tailed buds.

Renfro said:

I wouldn't wanna push plants at 90+ F unless running supplemental CO2. Yeah they may grow but they will usually make loose, airy, fox tailed buds.

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Agreed. I was thinking along the lines of hitting those high temps only for a bit, not all day.

Right on guys. I might get some co2 bags to help out I do have ac I can add if I have 2

corbin5754 said:

Right on guys. I might get some co2 bags to help out I do have ac I can add if I have 2

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How is your humidity? I would say if you are able to keep your humidity low but still have high temps the real issue is the ambient temperature and more air flow won't make a difference. For what its worth I have had grows hit the low 90s without issues the plants will just drink more. I had the highest yields that round too. The thing to remember is if plants drink more they will take in more nutrients so I may need to decrease the strength some to prevent burning.

The thing I am no expert on is adding co2 to a grow however I would think if you are running fans 24x7 putting bags in the tent would be useless.