Can't keep 4x4x7 room cool (without AC)

Yung Savvy

Yung Savvy

Member
I simply can't afford AC at this point, invested too much in my set-up I have 4x4x7 mylar tent with a 400 watt MH cool-tube reflector. I'm running standard 6 inch intake and outtake both leaving the room the tent is in itself, outside intake temps are consistently around 70. Except when it drops around 5-10 degrees at night.

My question is how can I keep this set-up cooler then the 85 degrees it seems to want to stay at constantly without adding any-type of AC unit?

Open to all and any forms of criticism at this point, please help!
 
rollinbud

rollinbud

Active Member
85 Temp. is fine. If I read you right you are only using your fans to suck air through your cool tube? Maybe you need an intake and exhaust on your tent, or at least a fan pushing cool air into the tent.
 
bobhoop

bobhoop

Active Member
I know 5 girls who love 85 degrees. Maybe your just a little close to the canopy and or you could use another little fan in there to blow some air around. goodluck:-P
 
georgyboy

georgyboy

Active Member
85 should be fine for most plants, but one way to lower the temps without adding anything to your setup is to make sure all of your ducting is smoothed out well and to make as few bends in the ducting as you can. Look at how you have your ducting and see if you can't run it any shorter than it already is. Make sure there aren't any tight turns in the ducting, because this drastically restricts airflow. If you don't have fresh air coming into your tent and the hot air going out, a hole at the bottom of your tent and one on the opposite side at the top with a circulating fan inside the tent may help also.
 
J

joseaf

Active Member
85 degree is fine for most plants. Unless you wish to use the extra exensive power to cool the tent, leave it alone and enjoy the harvest. my setup get upwards to 90 degrees in the summer and i get over a 1/4# of herbs every harvest from 4 plants under 400w HID. 4" inline fan, 4x2.5x6.
 
The Yorkshireman

The Yorkshireman

Well-Known Member
It's probably because you have a 6" intake AND a 6" exhaust.

Remove the intake altogether (or use BOTH fans for your exhaust) therefore creating negative pressure.

As a rule of thumb if you use an intake fan it should be 3 times smaller than your exhaust (courtesy of "Shantibaba").
 
+ WitchDoctor +

+ WitchDoctor +

Well-Known Member
Great advice from the yorkshireman. And you're right to feel that 85 is too high. Most strains like to flower under 80, with cooler temperatures at night. If you're growing some landrace sativas or something 85 would probably be idea, but I'm sure you're not.

If you have a fan exhausting the cool tube, and a fan at least 200 cfm exhausting the tent, you should be able to get it under 80 in there.
 
Yung Savvy

Yung Savvy

Member
Okay I sized my intake down to a 4" that's all I could find smaller then 6 inch at home depot.

Temps are actually up to 86 only 1 degree increase, but I will say today has been the hottest day at 91 since I've used this setup.
 
missnu

missnu

Well-Known Member
Yung Savvy said:
I simply can't afford AC at this point, invested too much in my set-up I have 4x4x7 mylar tent with a 400 watt MH cool-tube reflector. I'm running standard 6 inch intake and outtake both leaving the room the tent is in itself, outside intake temps are consistently around 70. Except when it drops around 5-10 degrees at night.

My question is how can I keep this set-up cooler then the 85 degrees it seems to want to stay at constantly without adding any-type of AC unit?



Open to all and any forms of criticism at this point, please help!
Click to expand...
So do you have a fan to just blow on the plants?
 
209 Cali closet grower

209 Cali closet grower

Well-Known Member
Yung Savvy said:
Okay I sized my intake down to a 4" that's all I could find smaller then 6 inch at home depot.

Temps are actually up to 86 only 1 degree increase, but I will say today has been the hottest day at 91 since I've used this setup.
Click to expand...
That's why your tent is to high, you need to move more hot are out.



.
 
M

medical/420

Active Member
you need a bigger intake, and more exsausrt fans, suck the air out of the tent. 6" is way better than 4" and 8" mmores a shit load of air
 
Dank Raptor

Dank Raptor

Active Member
intake is not really needed in a growtent guys. They have ports on the bottom that allow for a passive intake. What you want is more air blowing out of the top of the tent. (heat rises) and your cool air coming in from the bottom. Yes it will help the temps to have a fan inside blowing the air around.
Another suggestion to beat the heat. Run your lights at night. If they are in veg then put them on 18/6 with the 6 hours off being the hottest hours of the day. 2-8pm off :)
 
hellraizer30

hellraizer30

Rebel From The North
No he dont need a 8in he needs to pull air from inside the tent through the vented shield and then out of the tent, by doing this
he will get a vacume! Now you open the vent hole on the bottom of the tent, the vacume will pull air in and coll the tent. Also
try to keep the room that the tent is in as cool as you can get it.
 
PixiDustr

PixiDustr

Active Member
I have a 4x4x7 with a 400wMH (ballast is in light fixture). I have 4" exhaust fan (285cfm) pulling air from carbon filter across light and out through the top. I also have fresh intake 4" inline fan (65cfm). Add to this a 6" clipon fan blowing over my canopy. I have no issues with heat. If your light has separate ballast have it on the outside of the tent if you can. Hope this helps :)


IMAG0270.jpg
 
Yung Savvy

Yung Savvy

Member
PixiDustr said:
I have a 4x4x7 with a 400wMH (ballast is in light fixture). I have 4" exhaust fan (285cfm) pulling air from carbon filter across light and out through the top. I also have fresh intake 4" inline fan (65cfm). Add to this a 6" clipon fan blowing over my canopy. I have no issues with heat. If your light has separate ballast have it on the outside of the tent if you can. Hope this helps :)


View attachment 2198695
Click to expand...
I'm a very visual spacial learner honestly just having a visual reference to go on has helped more then any of the verbal (albeit being in text form) advice, so truly thank you.
 
4

420Jeep420

Member
Air cooled hood makes all the diff. In the room I have 3x3x8 room w/ 600watt HPS 200 cfm fan and 2 wall mount fans and I'm running 78 to 79 With tent closed and tent is bult in to a walk in closet not lookin too bad so far what y'all think HOW DO I POST A PIC?
 
4

420Jeep420

Member
Have u thought of cuting 4 or6in hole in ur celing or floor to tap in to ur central a/c ? Even with the a/c cycling it should help w/ temp .
 
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