6" inline for 2x4?

pegboy

pegboy

Well-Known Member
Nizza said:
-passive intake, be sure intake is around 3x the area of the exhaust fan. That would be two 6" passive intakes for a 4" exhaust (200 cfm ac infinity)
-Note: if adding a filter/ screen the exhaust will no longer push the 200 CFM it is advertised to. This goes for the intake holes as well-- if adding a screen to filter the intake it is good to increase the hole depending how fine the screen is to make up for the loss. I think you could probably get away with a second 4" fan used as an intake, which is how I like to set up (active intake + active exhaust), I use an intake filter as well.
-Use hard ducting to make it work most efficient. This will also make it louder though. Long sweep bends are better than short sweeps
-set up the exhaust fan up high, and the intake down low (humidity rises as well as heat)
- reduce evaporation from drain tray, pots, and reservoir if possible by capping
-thinning the foliage can help
-Make sure your hygrometer isn't effected by your lights and is giving an accurate reading
Click to expand...
Some nice suggestions!! Thanks !!
 
pegboy

pegboy

Well-Known Member
OK. Day off work so I'm monitoring what's going on.

LIGHTS ON:

HOUSE: temp 70F RH 40%
GROW ( prox 7'x 7') RM: 73F RH 46%
TENT: 75F RH 57% with fan blasting 9/10

SO do I go with a small room dehumidifier or step up from a 4" to a 6" inline fan system??

EDIT: pay no attention to the reading in the picture. That was from just after lights on.

EDIT 2: This is set up passive. Fan sucking air out of tent with low flaps wide open. Plants are around 24"tall. 3 fans for air movement.

IMG_20240424_070956982.jpgIMG_20240424_071035587.jpg
 
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Billy the Mountain

Billy the Mountain

Well-Known Member
I have a similar setup; a 4x2 tent or two in a small room/large closet (10'x6'). This 'lung room' is within a large basement.

If I exhaust into the lung room, similar to the pic above, the humidity never leaves the room and a dehumidifier is required to keep humidity in check.
I configure it that way when using CO2; otherwise I exhaust through a hole in the wall to the larger basement; no dehuhey is needed.

Also, pushing air through the filter is much more restrictive than pulling air though the filter and will require more fan speed for the same airflow.
 
pegboy

pegboy

Well-Known Member
Billy the Mountain said:
I have a similar setup; a 4x2 tent or two in a small room/large closet (10'x6'). This 'lung room' is within a large basement.

If I exhaust into the lung room, similar to the pic above, the humidity never leaves the room and a dehumidifier is required to keep humidity in check.
I configure it that way when using CO2; otherwise I exhaust through a hole in the wall to the larger basement; no dehuhey is needed.

Also, pushing air through the filter is much more restrictive than pulling air though the filter and will require more fan speed for the same airflow.
Click to expand...
Awesome. Do you think a 6" would at least equalize the room?
 
marzig

marzig

Well-Known Member
I have a 2x4x6 that I use a 6" fan and carbon filter in. Tent is in a 2x8 closet with by-pass doors which remained closed. Fan is vented through the attic to a roof vent. Air intake is through the two 6" vent holes at each end of the bottom of the tent. Apparently more than enough air finds it way in past the closed by-pass closet doors. I'm running 3-Mars TS1000s at 90% most of the time 18/6. In my home I'm either running the furnace or central air set at 73. Household RH averages 30 to 37%.

I've never had the tent RH above 40%, and it usually stays just a little above the house RH. even with 2-5gal dwc buckets. I can easily maintain temps between 75 to 82. Before this I was running a 4" fan and was never satisfied with heat or humidity levels.
 
ilovetoskiatalta

ilovetoskiatalta

Well-Known Member
Rivendell said:
Is your intake sufficient to let your current fan move the air? I assume it is, but just wanted to toss that out as I have seen folks struggle when the intake was not sized large enough to let the fan "Breathe" and it was just working like hell and not really moving much air.

Hope you get it figured out!
Click to expand...
what he said
 
Rocket Soul

Rocket Soul

Well-Known Member
Another strategy would be raising night time temps in you tent a bit, this will lower RH. But as always the humidity needs to be evacuated from the extended space somehow.

Its worth remembering that + transpiration means + growth and + humidity; the better you are at growing your plants the more humidity youll have and as such you need to not skimp on the humidity handling.
 
S

sessybudfarmer

Member
Please post how you resolved. This is my first tent grow and I've been having the exact same issue.

I'm almost positive my problem is a venting setup, but cant exhaust outside and didn't want the smell to get to nosey neighbors. I may have to say f'um
 
pegboy

pegboy

Well-Known Member
sessybudfarmer said:
Please post how you resolved. This is my first tent grow and I've been having the exact same issue.

I'm almost positive my problem is a venting setup, but cant exhaust outside and didn't want the smell to get to nosey neighbors. I may have to say f'um
Click to expand...
Haven't really resolved the issue for the long hall. Short term I've added another 4" in line fan that I had laying around and have been running my AC pretty continuous now that the weather is getting warmer. The AC has been pulling a lot of the humidity out of that room.
 
futurebanjo

futurebanjo

Well-Known Member
If your going to buy a new extractor, seriouslly consider an EC fan, they are a game changer and super powerful.
They are not cheap, but they are speed controlled inline with power consumption, I.e. if you dial it down to 50% it will use 50% less power to run, unlike traditional fans.

I've never looked back.


I've got one of these, 6" and its like a fricking jet engine on full power, it seriously spits out a tornado at the end of the ducting!
I run it under 50% power and it still sucks the sides of my tent in!! its really quiet too, well, not so much at 100%, but 50% and under you can hardley hear it.
drgreens.co.uk

Mammoth Juiced EC Fans | Dr Greens Hydroponics | Telford

Mammoth Juiced EC Fans | features controllable speed settings and comes in a sleek aluminium casing for maximum output of air.
drgreens.co.uk drgreens.co.uk

It will quite easily suck out humidity inside the tent, so you do have to balance the speed dial accorningly.

They are really small too, not much bigger than the ducting.

duct.jpg
 
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UnknownRemedy

UnknownRemedy

Well-Known Member
sessybudfarmer said:
Please post how you resolved. This is my first tent grow and I've been having the exact same issue.

I'm almost positive my problem is a venting setup, but cant exhaust outside and didn't want the smell to get to nosey neighbors. I may have to say f'um
Click to expand...
What I did to resolve my issue is a turning on my big dehumidifier outside of my tent while my exhaust fan ran full speed. Dry air goes into the tent and humid air gets sucked out.

Do you not have a good carbon filter? That gets rid of tons of smell.
 
futurebanjo

futurebanjo

Well-Known Member
Billy the Mountain said:
I have a similar setup; a 4x2 tent or two in a small room/large closet (10'x6'). This 'lung room' is within a large basement.

If I exhaust into the lung room, similar to the pic above, the humidity never leaves the room and a dehumidifier is required to keep humidity in check.
I configure it that way when using CO2; otherwise I exhaust through a hole in the wall to the larger basement; no dehuhey is needed.

Also, pushing air through the filter is much more restrictive than pulling air though the filter and will require more fan speed for the same airflow.
Click to expand...

Good point, if you are re-circulating air in the same room as the tent, then excess humidity will also re-circulate...you really need to vent exhaust into a different space.
A dehmidifier should help here but it's another peice of equipment and and another thing using electricity.
 
S

sessybudfarmer

Member
UnknownRemedy said:
What I did to resolve my issue is a turning on my big dehumidifier outside of my tent while my exhaust fan ran full speed. Dry air goes into the tent and humid air gets sucked out.

Do you not have a good carbon filter? That gets rid of tons of smell.
Click to expand...

I currently have it setup as you describe, but unzipped the front door partially and put a box fan in front of the tent. Its the only way humidity goes down. (Thus the smell)
My exhaust fan/filter isn't at full speed, its a little over 50%

I really don't like running the dehumidifier continually as it eats up the electric, and my ac is already running full blast due to the 100 degree outdoor temps, so I was trying to configure another way. Its give/take game playing with this and I'm no hvac person

My humidity has stabilized at 58-60% and temp is 75-77 degrees.

I didn't want to post until I knew I had cured the issue I was having. I dont know that I've cured it but its the best I have under the current conditions. I know when temps outdoors drop so will the temp/humidity in the home and tent
 
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