Odd problem, very odd :P

Hey all, long time prowler, new time member
Have a bit of an oddity here, unsure how to solve it. heres my grow box specs.

2 feet 4 inch long/wide
2 feet high/tall
1 feet 5 inches deep/depth

For all intents and purposes, after you take into account the light traps, fixtures etc, theres 4 square feet of AIR space, which is more important then actual space because of fan CFM.

I was told that you should have a total air cycle of about 3 to 5 times per minute, since my growbox is 4 ft/squred, cycling that 5 times per minute i would need 4x5 = 20 cfm, being generous I have 2 12v PC fans with a CFM rating of 60 in there. so, every 20 seconds, the air should be fully cycled, to my understanding. Correct me if im wrong.

Now heres the box specs (Design)
It is a cabinate with 2 sliding doors, the cabinate is fully light and air proof, with the exception of the fans.
The top left of the box has a 60 CFM exhaust, inside the light trap i put a bean bag filled with activated carbon, and it works. Air can flow around it too, 2CM on all sides, so it does not empede air flow.
On the top right of the box, i have a 60 CFM intake fan on a light trap with no filtration, so free flowing air..
The cabinate, standing 2 feet tall is factory white. So NO reflective materials was used, at all. its a flat white already.
which i felt was good enough for my 3 plant plans.

For lighting i have non-adjutable height. 3 figtures, spaced equally, screwed to the back wall so the bulbs are situated front to back evenly "Ill use something to prop the plants up, rather then adjust the lights down. ill choose something with a hollow interior, so the cubic air in the box will remain unchanged. like a metal rack" maybe wood i can hammer one together.

The 3 lights are 120v CFL.
All 3 are 2700k color, i wont be using 6500 to flower.

the left one is a 1700 lumen
the middle one is a 2700 lumen
and the right one is 1700 lumen.

6100 lumen "3050 sq/ft" which is enough
I cant go higher yet, youll find out why in a second. The total wattage for the 3 bulbs is 110-120 watts of energy.
They are of coursed, self ballased "cfl ;p"

2 Feet away from the box, in the front. clear and away from any exhaust

AMBIANCE: 25.5*C / 77.9*F 18%RH (omfg!)

INTERNAL BOX fans on: 29.7*C / 85.5*F 18%RH (Temperature spikes ive seen in the 31*C area (about 91*F))

INTERNAL BOX night drops to ambiant 25*C in about 30mins-45mins (fans go off when the lights do)

daytime with fans off 32*C RH unchanged

Afterwatering RH has been seen as high as 80%, im going to have to leave the door open after watering for an hour or two.


Now im stumped here, because ive just increased the fan capacity +20CFM each and increased the voltage from 12 to 15 "Increased the RPM by 2500" and the temperature is down by 0.3*F"


I know I can grow in this box, ill have to water a helluva lot more then usual and watch them like a hawk. But id rather not have to, is there something im missing?


Sorry for long post but i felt in required to get a solid response.

Well your fans should be intake on the bottom and out on top so that you aren't recycling the air you want it to pull cool air which is low and exhaust it outta the top. just my 2 cents but other than that everything sounds fine. maybe try running your lights at night when its cooler.

Lokee said:

Well your fans should be intake on the bottom and out on top so that you aren't recycling the air you want it to pull cool air which is low and exhaust it outta the top. just my 2 cents but other than that everything sounds fine. maybe try running your lights at night when its cooler.

Click to expand...

Well I could just build a small duct to release the intake lower to the ground rather then higher up. but there is 2 feet between the fans, i didnt expect that it would recycle the same air at only 60 CFM


Ohh forgot to mention i have a 1L jug at all times in there fermenting sugar "Small amount of extra CO2"

Ok update:
I took your advice and i have moved the intake. all air through the intake is injected at the bottom right now, temperature is unchanged, but seems more stagnant.
hotter air pockets seem to form at the top now. but the actual temperature seems unchanged as i said.

What i did was took out the old light trap and factioned a new one, that instead of comming in like htis

FAN] =====] -> air "Air trap come directly in along the roof, and brang in the air"

now does this

FAN]=
=
=
=
=
Air<- = "Air now comes in, is directed in a vent down the wall, and let in at the back of the grow box 5 inches above the floor"



For humidity i hear best to get it higher, to at least 40%
Im thinking a small glass of water sitting in there would probably do it
and to just fill it back up when it goes empty.


The Co2 tube is now interfaced with the intake, so its not being blown out into the middle, rather its injected with a tube into the intake vent. and comes in with all
the fresh air. "So the cool new fresh air will have much more C02 basically"

still facing the same problems otherwise.

samljer said:

Ok update:
I took your advice and i have moved the intake. all air through the intake is injected at the bottom right now, temperature is unchanged, but seems more stagnant.
hotter air pockets seem to form at the top now. but the actual temperature seems unchanged as i said.

What i did was took out the old light trap and factioned a new one, that instead of comming in like htis

FAN] =====] -> air "Air trap come directly in along the roof, and brang in the air"

now does this

FAN]=
=
=
=
=
Air<- = "Air now comes in, is directed in a vent down the wall, and let in at the back of the grow box 5 inches above the floor"



For humidity i hear best to get it higher, to at least 40%
Im thinking a small glass of water sitting in there would probably do it
and to just fill it back up when it goes empty.


The Co2 tube is now interfaced with the intake, so its not being blown out into the middle, rather its injected with a tube into the intake vent. and comes in with all
the fresh air. "So the cool new fresh air will have much more C02 basically"

still facing the same problems otherwise.

Click to expand...

I never used an intake fan in any of my grows. Ill make sure there is a small hole or a vent down at he bottom of my room. Then for exhaust, My carbon air scrubber blew the hot air through another vent in the ceiling. imho, If you have two fans with the same cfm, you wont get reduced temps, or proper air flow. You pretty much defeat the whole purpose.

CLOSETGROWTH said:

I never used an intake fan in any of my grows. Ill make sure there is a small hole or a vent down at he bottom of my room. Then for exhaust, My carbon air scrubber blew the hot air through another vent in the ceiling. imho, If you have two fans with the same cfm, you wont get reduced temps, or proper air flow. You pretty much defeat the whole purpose.

Click to expand...

The 12v fans are wired through thier own power buttons, when intake was off and exhaust was on, the temp went up to 92*F

that cant be it ;/

The box just entered dark cycle wont be able to continue trouble shooting untill tomorow, thanks for the tips

samljer said:

The 12v fans are wired through thier own power buttons, when intake was off and exhaust was on, the temp went up to 92*F

that cant be it ;/

The box just entered dark cycle wont be able to continue trouble shooting untill tomorow, thanks for the tips

Click to expand...

In the attached pictures you see:

In the first picture labeled 7, the outside of the box, on top. You can see the ionizer catches all the exhaust and filters it. 2L of clean water, and 1L of 1/4 strength miracle grow. Oh and no XBOX360s were harmed in the making of that picture


In the second picture, labeled as 9. You can see the right side of the box, the tubes on the far side are intake vents, brings in cool air at 30CFM, you can see my CO2 Mix bubble away. as well as a Mango tree's broad flat leaves. "oh and the thin leaf one is corn"


In the third picture, labeled as 10. you see the dial, sorry its blurry. my camera blurrs like this when batteries are about dead. its a dial MEANT for plants and as you can see, both dials are in the RED. the small one is RH% which right now is reading 18% "The black fuss in the colored band is actually 10-20-30-40 lettering" and the large one, temperature is readin 30*C on the dot.
OH!! ignore the dates!! 2104 lol.


The fourth picture shows the lights. you can see the middle and right light only. 2700 and 1700 lumen respectively.
You can see the light trap to the intake fan as well. and the addition i made yesterday to vent it down.


Picture five is a blurry upclose of the mango tree FLOURISHING under the intense conditions in the box ;/
the corn seems to grow, but looks as its unconfortable.


Picture six, you can see the wiring to the fans and the left light 1700 lumen cfl.
the dial mounted on the back wall. my cutting sissors (wow i cant spell that?) that are mounted on my wire bracket that i use for them and other small tools.
the corn plant, which is about to be removed from the box, its like 3feet tall ;/