Split Exhaust Idea for Tent

S

SoN3at

Member
So temps in my tent have been getting up to 90 when it is over 80 outside. I have a A/C unit inside my tent but it doesn't really do much on hot days. I currently have one exhaust fan suspended at the top of the tent inside that pulls air out a window.

I have an idea, gonna cost about $100 bucks so I'm kinda here to confirm that it is a good idea before I spend money on it. I'm thinking about getting some 3 way duct splitters, putting two of them together and sticking one end on my exhaust fan which I will put outside of my tent. This will give me 3 duct ports to pull air through with the fan. I have 4 holes on top of my tent but I can only really get to three of them, so I am thinking I will run 3 duct hoses from 3 holes to the fan and this way I will be pulling air from the very top of the tent where heat is probably getting trapped, and from 3 different areas.

I think it sounds like a good idea... seems to me like it will be more effective. Thoughts?
 
coreywebster

coreywebster

Well-Known Member
It will be the same or worse, the fans cfm will remain the same, the choke point in the duct will be the same.

The only thing you can do is cool the room with a better AC so your incoming air is cooler to start with
Or buy a bigger extraction fan , the more air you move through the tent the less the temp will rise.
I would go with the AC option and cool the room if its over 80 outside.

I assume your running lights on at night and off in the hottest part of the day already.
 
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S

SoN3at

Member
coreywebster said:
It will be the same or worse, the fans cfm will remain the same, the choke point in the duct will be the same.

The only thing you can do is cool the room with a better AC so your incoming air is cooler to start with
Or buy a bigger extraction fan , the more air you move through the tent the less the temp will rise.
I would go with the AC option and cool the room if its over 80 outside.

I assume your running lights on at night and off in the hottest part of the day already.
Click to expand...
How can you be so sure it will be the same or worse? If air is being pulled from one location inside the tent, the hot air all has to pass through that one point. If there are 3 points where where air is being pulled, the hot air should be removed faster?

That's how I am seeing it. Could be wrong.

The AC I have is just as good if not better than any other on the market, one of the top brands. It is a portable AC unit, collects water and cools the air. My extraction fan is also pretty decent. Can Fan, Max Fan or whatever they are called, I think its somewhere around 360 cfm. I have thought about trying to somehow mold some kind of ductwork around the awkward vent where the cooled air comes out of the AC unit and vent it into the tent with the AC unit outside of the tent. The AC unit lowers humidity and from what I understand that doesn't really help to cool things off. Plus I am sure it puts out some heat just by running in the enclosed space (8x8).
 
coreywebster

coreywebster

Well-Known Member
The air going out can only be what the cfm of the fan is rated for and the single exit point is capable of keeping up.
If you have 3 points of exit they have to converge to a single point somewhere so your still only pulling the same air.
I say "or worse" because when you add more ducting you add more resistance which lowers the airflow to some degree.

As for AC they create heat, which you need to remove. Least that's the way I understand them.
You need to cool the room not the tent. If its possible to make it so its out the tent but pumps the cool air in the tent then that may be a lot more efficient.

I don't doubt your fan is good but its as simple as this, the less temp rise you want the more air has to be exchanged , its a losing battle if your air is already warmer than you want it to be.
The AC is the better option so you can actual lower the ambient air temp of the room
 
TintEastwood

TintEastwood

Well-Known Member
It's about the temperature of the intake air.

I'm in Norcal and have the same problem during the summer. Intake air temps exceed 90f.
My solution is to shutdown growing for the summer.

But, if I'm hard up for stash this works too. Sealed with AC, and proper venting. At the cost of running the AC.
0327181758a.jpg
 
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rmax

Well-Known Member
86°F outside.
The thermometer inside at ground floor reads 81°F.
Two thermometers in the basement. One is reading 81°F (digital) and the other 80°F (analog).
Inside the tent is 88°F (analog).

My dehumidifier is creating heat down there and the lights. I have my fan duct blowing at a window.
 
Nizza

Nizza

Well-Known Member
TintEastwood said:
Ditto here. A 50pint dehuey gets the job done in my 4x8x8.
They generate serious heat.

Arghhh. I must resist the urge to set it up to pull air from my residence! Sweet 75f air!
Click to expand...
I wonder if running the A/C on DRY mode would eliminate the extra need for cooling from the dehumidifier..
but the BTU output will be reduced on dry mode, it works by running a lower fan speed
 
TintEastwood

TintEastwood

Well-Known Member
Nizza said:
I wonder if running the A/C on DRY mode would eliminate the extra need for cooling from the dehumidifier..
but the BTU output will be reduced on dry mode, it works by running a lower fan speed
Click to expand...
That might work if AC cooling is not needed. They remove some RH, but not always enough in my space.
 
downhill21

downhill21

Well-Known Member
TintEastwood said:
It's about the temperature of the intake air.

I'm in Norcal and have the same problem during the summer. Intake air temps exceed 90f.
My solution is to shutdown growing for the summer.

But, if I'm hard up for stash this works too. Sealed with AC, and proper venting. At the cost of running the AC.
View attachment 4610031
Click to expand...
I like the clean & simple install / retrofit. That’s quite a door ya got there, dude.
 
S

SoN3at

Member
well. I don't know what the hell I'm gonna do. I guess I'll have to go to home depot and stare at the duct isle for an hour and try to come up with a way to piece together something that will fit snugly in the ac unit vent. I guess I could also look into maybe getting another exhaust fan but my circuits are already pretty maxed out so that probably isn't even an option.

Kinda confused about people mentioning using dehumidifiers to cool, I have been under the impression higher humidity will lower the temp.

Yet another option I suppose, would be putting a window a/c unit in the room that the tent is in, and getting rid of the portable a/c unit altogether... would be a very tight fit though. Window AC unit would probably be an inch or less away from the side of the tent unless I could find a very very shallow one.

I put the A/C unit on dry mode per someones suggestion here, and the temperature actually went down a little over a degree in less than 15 minutes. Might have to experiment with this.

If anyone has any ideas for a way to vent this into tent, here is a pic of the A/C vent. The two grilles can be popped out.

IMG_7140[1].JPG
 
TintEastwood

TintEastwood

Well-Known Member
Not ideal, but I would probably drop down to a single 4x4 tent. Get one running proper.

Spawn second tent at a later date.

Or. Use second tent as lung room containing AC and dehueified air.

Dump heat out the window.



If needed...
www.homedepot.com

VENTS-US 6 in. Galvanized Back-Draft Damper with Rubber Seal KOM 150 U - The Home Depot

VENTS 6 in. KOM 150 U round back valve is especially designed to prevent back-draft. The spring loaded back-draft damper is manufactured of galvanized steel and contains rubber seal. Easily fits into your vent system, the installation requires minimal labor and time.
www.homedepot.com
 
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S

SoN3at

Member
TintEastwood said:
Not ideal, but I would probably drop down to a single 4x4 tent. Get one running proper.

Spawn second tent at a later date.
Click to expand...
I'm not gonna spend money on a 4x4.. don't really see the point. If anything I would just get rid of the tent altogether and put a window A/c unit, cool the entire room and go from there. I like using the 8x8 though, I feel like it gives me an extra layer of protection from dust/dirt/bugs/etc. This is my current problem and I'm gonna stick to it.... buying another tent I would probably just encounter a host of new issues and waste time. Gonna work with what I got. I've used this setup before with an HPS and I always made it through flower just fine... I'm using LEDS this time around so my temps are lower than they were when I had the same issue before. I know it'll work out regardless but I would like to dial it in and make it right.
 
S

SoN3at

Member
TintEastwood said:
Not ideal, but I would probably drop down to a single 4x4 tent. Get one running proper.

Spawn second tent at a later date.

Or. Use second tent as lung room containing AC and dehueified air.

Dump heat out the window.



If needed...
www.homedepot.com

VENTS-US 6 in. Galvanized Back-Draft Damper with Rubber Seal KOM 150 U - The Home Depot

VENTS 6 in. KOM 150 U round back valve is especially designed to prevent back-draft. The spring loaded back-draft damper is manufactured of galvanized steel and contains rubber seal. Easily fits into your vent system, the installation requires minimal labor and time.
www.homedepot.com
Click to expand...
The only remaining space outside of the 8x8 is a 1ft x 8 ft stretch along one side where window is located and then a closet about 3 feet deep and 5 feet wide. Currently have clones in there under a T5. Enough room for the AC unit out there and that's about it.
 
TintEastwood

TintEastwood

Well-Known Member
Ok. Did not realize you have run there in the past.

I have a 6k wall banger in my 4x8x8 sealed room - vented during lights out. (630w cmh.)

AC works its ass off during the summer.

My fav enviro techno link.
medteknutrients.com.au

CO2 Enriched Hydroponic Growing | Manic Botanix

The CO2 fertilizer effect. Article covers contemporary research about yield increases in under lights growing with CO2 enrichment. Optimum ppm and growth.
medteknutrients.com.au medteknutrients.com.au
 
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rmax

Well-Known Member
SoN3at said:
If anyone has any ideas for a way to vent this into tent, here is a pic of the A/C vent. The two grilles can be popped out.
Click to expand...
Hey, to the best of your ability draw a top view of the room and post (draw on paper and pic w/phone?). We need to know where the tent is in proximity to the windows and doors. From the top view point out where your fan is located and also the AC unit.

Dehumidifiers can't be vented to outside but AC units must be vented to outside. On that AC unit are you venting the heat from the unit out the window?

Basically you want the AC unit exhaust venting to outside.
Then you want the tent fan blowing the cool AC air into the tent and exhaust out the now warmed air out the window to outside. Get the hot out of the building.
 
S

SoN3at

Member
rmax said:
Hey, to the best of your ability draw a top view of the room and post (draw on paper and pic w/phone?). We need to know where the tent is in proximity to the windows and doors. From the top view point out where your fan is located and also the AC unit.

Dehumidifiers can't be vented to outside but AC units must be vented to outside. On that AC unit are you venting the heat from the unit out the window?

Basically you want the AC unit exhaust venting to outside.
Then you want the tent fan blowing the cool AC air into the tent and exhaust out the now warmed air out the window to outside. Get the hot out of the building.
Click to expand...
I will draw a pic and post tomorrow, worked all day and almost midnight here...need some sleep lol. But, the AC unit has a 6" hose going out of the tent and to the window. I have an intake fan bringing in air from outside, but on very very hot days I just remove the hose to the window and take in air from the room...but even on hot days its usually hotter in the room than it is outside.. I then also have an exhaust fan inside the tent pushing air out the window.

SO, air coming in from outside in bottom of tent, AC unit sucking up warm air inside tent, cooling it and pushing it back out inside tent, and then warm air sucked out of tent with exhaust fan near top of tent ceiling and pushed through window.

Gotta be a better way. Will post pic tomorrow
EDIT*** Pic in next post... can't sleep If I'm thinking about this.
 
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S

SoN3at

Member
rmax said:
Hey, to the best of your ability draw a top view of the room and post (draw on paper and pic w/phone?). We need to know where the tent is in proximity to the windows and doors. From the top view point out where your fan is located and also the AC unit.

Dehumidifiers can't be vented to outside but AC units must be vented to outside. On that AC unit are you venting the heat from the unit out the window?

Basically you want the AC unit exhaust venting to outside.
Then you want the tent fan blowing the cool AC air into the tent and exhaust out the now warmed air out the window to outside. Get the hot out of the building.
Click to expand...
IMG_7143[1].JPG
 
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