Problems With Keeping Tent Cool

Onetwothree · May 28, 2016

I have a 4x2x5 grow tent with a 600w air cooled hood set up. I recently swapped out a Ven Tech 440 cfm fan for a Can Fan Max pro series 420 cfm. The Ven tech was super noisy but was doing a good job otherwise. Now, my issue is my area just got nailed with a pretty bad heat wave. The tent is in my garage where the temps are around 77, but the tent is getting up to 87 with lights on.

Now, you would think a 420 cfm top of the line fan would be able to handle such a small tent no problem right? I have the fan pulling the hot air from the light and spitting it out...so the set up is carbon filter-->light-->fan. Is my set up flawed? I should mention the filter is a 200 cfm phresh. The filter and light are obviously both in the tent with the fan outside the tent.

Any thoughts?

DrMcSkunkins · May 28, 2016

You will need an air conditioned room to control the temp. The air inside the tent will never match the air outside with the light on.

Larger fans are actually quieter, and also cool better. A larger cfm fan and filter would get the number closer to 77 now but in the mid summer sun you will need a window unit for sure.

str8smokn · May 28, 2016

Do you still have the old fan?
What you need to do is cool the light off with fresh 77* air from outside of tent.
Tape up your light so no air leaks,bring fresh air from outside of tent straight through light and out of tent. No need to filter it since it's not removing air from tent.
Then use your other fan as a exhaust for the tent with your filter on it .
You can not cool off a light if your using hot air to begin with..
This is how it should actually be done..
STR8

Onetwothree · May 28, 2016

Thanks for the advice guys. I do still have the other fan. I was hoping to not have to use both (electric is a bitch!) but I'll give that a shot.

str8smokn · May 28, 2016

I would try that before I hook up a AC unit.
Good luck with it..
STR8

We Solidarity · May 29, 2016

You're not gonna cool the tent if it's 75+ degrees out and you've got a constant heat source. Best solution is A/C or get a lower wattage bulb.

DemonTrich · May 29, 2016

Ac is your only option with your temps. Can't cool hot air with more hot air. With fans, your just moving already hot air around, not cooling it. Since your in a small tent, you can make your own ac type unit. Using a cooler, ice, and a fan. There's a diy tek on it somewhere about it. Not sure how good itnis, but for a small tent, I'd check into it. Maybe use dry ice vs ice for longer cooling times. But again, if it were me I'd score an 8k btu portable ac, or build a cab and exhaust for a window shaker unit.

Onetwothree · May 30, 2016

Thanks for all the advice guys. So yea I hooked up the fans in the proper fashion that STR8 described. It helped out a bit for sure but it looks like the only way to really solve the problem is an AC unit.

ShroomKing · May 30, 2016

Use the old fan to push fresh air into the tent, the new one for exhaust. Make sure that you have every single intake port as possible open.
Best of luck.

Fatty LIVES · May 30, 2016

I'm not sure if this will work in your situation, but it worked for me. I was using too much EXIT air in my tent. I went with a shorter exit flow and upped the air intake and i dropped 4-5 degrees. sometimes my tent is cooler by 2 degrees than my room is.. Just using a good floor fan with like a cage fan inside.. duct taped a 6" duct and split it with a 6 to 6x6 for intake to both sides. 1 6" inline duct fan for exit.

Fatty LIVES · May 30, 2016

basically the logic is to keep your ac in... rather than trying to constant flush it out.. creating a great negative pressure

Onetwothree · Jun 4, 2016

So I've managed to keep my lights on temp at around 84, I know it's not optimal, but without installing a mini split AC unit, it's the best I can do.

Now my question to you knowledgeable folks is this: my plants will be harvested in 5 days...do I just wait out the summer months and fire up the tent again in the fall when it's cooler, or is 85 not all that bad? I know optimally I would like to keep the tent around 75 when flowering, but how much is it really going to effect the end product?

As always, all of your feedback is appreciated.

SpiderK · Jun 4, 2016

what size room is the tent in ?

say it's in a large room. you can build a " room " around the tent with 3 mil plastic. then control this environment and exhaust out of tent, past the three mil area and dump old air into larger room ..... so you only are cooling a small area around tent. could even use a swamp cooler for the small 3 mil room.

Onetwothree · Jun 4, 2016

SpiderK said:
what size room is the tent in ?

say it's in a large room. you can build a " room " around the tent with 3 mil plastic. then control this environment and exhaust out of tent, past the three mil area and dump old air into larger room ..... so you only are cooling a small area around tent. could even use a swamp cooler for the small 3 mil room.

That's a cool idea, I'll check that out. I'm in a garage, and have a small "room" inside the garage with my tent. Basically 3 walls and then a sliding door that barely fits the tent.

DemonTrich · Jun 4, 2016

You can't use a portable ac unit? Only needs a dryer vent sized area to exhaust. I'm in a basement setting, and I vent out a window.

Onetwothree · Jun 4, 2016

DemonTrich said:
You can't use a portable ac unit? Only needs a dryer vent sized area to exhaust. I'm in a basement setting, and I vent out a window.

Negative, unfortunately there's no way to exhaust out in my garage. No windows at all.

Cryptic · Oct 13, 2016

i have a 2 1/2 x 2 1/2 with a 400 hps and my tent runs hot. like 90 to 100 in the summer months. i have one exhaust fan running out the top and the door wide open with a fan blowing air in. the room is only like 75 and im not sure how to cool it further. any ideas?

rmoltis · Oct 13, 2016

Cryptic said:
i have a 2 1/2 x 2 1/2 with a 400 hps and my tent runs hot. like 90 to 100 in the summer months. i have one exhaust fan running out the top and the door wide open with a fan blowing air in. the room is only like 75 and im not sure how to cool it further. any ideas?

Sounds like you need to either:

Get a cooltube setup.

Buy a better day/night fan controller (this helps a lot by reacting quickly to environmental changes).

It's possible you need a higher capacity exhaust system? Bigger fan, wider ducting?

Reduce the temperature of the room the tent is in. Until tent temp hits where you want it.

Or all of the above because,
I have a 2x2 flowering chamber.
And with the 400 watt hps my tent sits around °80-°84. House a/c set to °75 now that outside temps are dropping.
During summer a/c needed to be set at °68

If I had a 2.5×2.5 tent I'd be rocking a 600watt hid it would give me around 2,200 lumens per cubic ft.

My 400 watt in a 2x2x6 gives me 2,750 lumens per cubic ft.

With the 2 supplemental led bulbs (1600 lumens each) puts my lumens per cubic ft @ 2,910.

Your tent should control that heat very well.

Fatty LIVES · Oct 18, 2016

Cryptic said:
i have a 2 1/2 x 2 1/2 with a 400 hps and my tent runs hot. like 90 to 100 in the summer months. i have one exhaust fan running out the top and the door wide open with a fan blowing air in. the room is only like 75 and im not sure how to cool it further. any ideas?

duct AC into there, blast a fan on the bulb if you don't have an independent. What I did.. dropped it 20 deg :). I went through the same jazz

One drop · Oct 21, 2016

Hi I have had a similar problem I'm using 3'x3'x6' tent with 6" exhaust fan, carbon filter and silencer , 600 hps with a small shade hood . I had a spike in the heat which caused a bit of heat stress and sent some of the heads to foxtail , had to flush 3 days then harvest the affected heads then came back into bloom and I added some Seasol at recamended rates this has a good affect on helping the plant with heat stress ,to fix my problem I raised my light as far up as I could alowing a 6" gap and still being approx 2' above the existing heads then got some white shade cloth which is the best shade for flowering plants and cable tied it across the top of the crop this brought my temp down by 10 to 12 degrees . I hope that helps

Problems With Keeping Tent Cool

Problems With Keeping Tent Cool

Onetwothree

DrMcSkunkins

Dabbling in Oil

str8smokn

Onetwothree

str8smokn

We Solidarity

DemonTrich

Onetwothree

ShroomKing

Best of luck. Peace

Fatty LIVES

Fatty LIVES

Onetwothree

SpiderK

Onetwothree

DemonTrich

Onetwothree

Cryptic

rmoltis

The Beast Slayer

Fatty LIVES

One drop

Bush Doctor

Problems With Keeping Tent Cool

Problems With Keeping Tent Cool

Onetwothree

DrMcSkunkins

Dabbling in Oil

str8smokn

Onetwothree

str8smokn

We Solidarity

DemonTrich

Onetwothree

ShroomKing

Best of luck. Peace

Fatty LIVES

Fatty LIVES

Onetwothree

SpiderK

Onetwothree

DemonTrich

Onetwothree

Cryptic

rmoltis

The Beast Slayer

Fatty LIVES

One drop

Bush Doctor

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