Newbie struggling with heat. Please advise

I have a 6x6x9 grow room framed for a medical marijuana grow. I have 2 600 watt HID MH bulbs on a 18/6 schedule. Dark temp in 60's, but now my day temps are getting to 85-87 which is too how. I have a 412 cfm fan and carbon filter and a occ fan which also can heat for really cold winter days. I have a dehumidifier that keeps humidity between 30-33. Added yeast co2 to two plants, but don't know how to cool room down. Need to drop temp about 5 degrees. Is the only way a portable ac? Another oscalating fan? Please advise. Worried with temps slowly raising outside I need to figure out how to cool my white widow and THC bomb plants.

Where/how are you getting fresh air ? And are the lamps in cool tube ? What hours of the day are you running ?

Perhaps and investment in a small portable A/C unit would be best. Maybe one that would allow you to set a timer and control the temperature to an exact. It just might take the stress away of worrying of constant monitoring. I hope this has been informative. Best of luck to you friend. :]

Having the lights off for the 6 hottest hours of the day will help lower temps. Intake air is important and sometimes over looked. If money allows a ductless split is also an option.

Is the dehum in the room ? Because if it is and your in veg running @ 30-33% humidity that humidity is too low and that would cause excessive run times on the dehum generating unwanted heat. Plus high heat and low humidity must have you watering like every couple hours if you are you might be causing yourself problems down the road.

I do not have cool tube. I run from 4 am til 10 pm. I do not have a fan blowing air in, but their is 1/2 inch gap under the door and with my fan, carbon filter I vent the whole room every minute. Anything I should do?

Dehumidifier is in room. Aren't ductless split systems very expensive? Are the hard to install? I just have a framed in bathroom drywall with a door. I vent through roof vent.

They are expensive and can be difficult to install. I'd start by having the lights on at 6pm instead of 4am. Avoid the daytime heat that way.

Peaceman12 said:

I do not have cool tube. I run from 4 am til 10 pm. I do not have a fan blowing air in, but their is 1/2 inch gap under the door and with my fan, carbon filter I vent the whole room every minute. Anything I should do?

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Hey bro
You're running your lights during the hottest parts of the day.....I run my lights 8pm - 8am, and this helps a lot with temps.
Is your dehumidifier putting out much heat?.... if it is you could only run it when lights are off and RH jumps.
If you want good results you should really look at getting an intake fan....air flow is just as important as light and water.

I hope it works out for you... sending some growing karma your way

You need an intake fan the 1/2 inch gap won't cut it and you put more stress on the exhaust fan that way too. I put my intakes low to the ground so your getting colder air. I'd also cover the 1/2 inch gap and make that room as light tight as possible. Flowering plants don't like light during the dark cycle and will reward you with herms if you don't follow the rules.

I'm going to order a intake fan, close gap in door and change light cycle to dark from 12-6 dark during the day. I'll buy a portable AC if all else fails. Thanks to all of your advice on this forum. I love this site. Blessings to all

Peaceman12 said:

I'm going to order a intake fan, close gap in door and change light cycle to dark from 12-6 dark during the day. I'll buy a portable AC if all else fails. Thanks to all of your advice on this forum. I love this site. Blessings to all

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That will have you sorted bro, you more than likely won't need an AC.

Best of luck, and take lot's of pics.....we all love pics here at RIU

Here's a Critical Jack just finished to get you motivated!--

theese 2 always work
1. run lights at night
2. Cooled hoods or cooltube

also getting intake air will reduce temps a bit.
what you can also do is to put a few frozen pet bottles in front of the intake fam so that the air that gets sucked in gets a bit cooled.

Also i belive your humidity should be higher if you are in veg phase.. 33% just sounds a bit low to me for veg stage ..

A portable AC would probably solve your problem, but it will aslo consume LOTS of extra electricity! there are other steps to be tested first in my oppinion since a AC unit is way to expensive to buy and run unless its not 100% necessary. just my 2c

an intake fan is unnecessary. You only need to increase your intake sizing. for a 412 cfm fan you'll need approximately a 10"-12" passive intake.

also, 30% rh is lower than you need. raise rh to around 50% and your dehumidy will run less putting less heat into your room.

like another said, run your lights at night.

and stay away from those pos portable ac's. those things SUCK!.... literally. it'll suck air from your flower room out and release it into the world for all to smell.

legal grower or not this is always unwanted attention.

personally, I wouldn't mess around with a minisplit for only 1200 watts. you are better off figuring out a way to put a window unit in. They do not exchange indoor/outdoor air. unlike a portable