Ventilation set up

[RedDirtRay]

New indoor grower. Question, I have a 190 cfm 4” inline fan with carbon filter. Using the inline fan to exhaust air outside. It seems strong enough to pull cool air from the room and exhaust the tent, exchange air. I’ve been told I can use this set up but I’ve also been told I need an intake fan to pull air from outside. Here in Oklahoma it gets hot as you know what during the summer. I don’t want to have to buy an ac unit for the tent 3x3x6. Can I get away with using just the one inline fan for ventilation without pulling hot air in from outside? Nothing in ten yet. Been running it to see what the temp and humidity is with this set up. So far temp has a high of 84 and humidity of 62%. Lows have been 72 temp and 36% humidity. Currently it’s at 54% humidity and 74 temp.

 

[Chris Scorpio]

Why would you want to bring hotter air into the tent from outside your house???

Vent into the tent from holes at bottom of the tent
Run yer exhaust outside the house or to yer ceiling vents from the top of the tent

Easy peasy

 

[Metal Halide]

During veg, use your tent flaps to draw air into your tent from your grow space.
During flower use ducting to draw air in from your living area if possible since it is usually a more stable and normalised environment, richer in Co2.
Always check the environment status from where you're bringing fresh air from first, Not the tent itself. Once you have a stable temp/humidity there then try to mimic it in the tent aswell by dragging in the correct amount of air, having the right lighting for your current situation, possibly using an intake, possibly using cooling/heating, dehumidifier ect ect, but start off in the order i suggested to keep costs down unless your grow space is in a place already exposed to the elements (which it shouldn't).

You can def just use an exhaust to work as an intake aswell but be sure to make the inlet bigger than the fan itself. So if the fan is a 6" then use an 8" inlet duct or two 6". I personally use both an intake fan and a vent to help with humidity and take the burden off the exhaust while maintaining negative pressure to assist in total carbon filtering

 

[RedDirtRay]

During veg, use your tent flaps to draw air into your tent from your grow space.
During flower use ducting to draw air in from your living area if possible since it is usually a more stable and normalised environment, richer in Co2.
Always check the environment status from where you're bringing fresh air from first, Not the tent itself. Once you have a stable temp/humidity there then try to mimic it in the tent aswell by dragging in the correct amount of air, having the right lighting for your current situation, possibly using an intake, possibly using cooling/heating, dehumidifier ect ect, but start off in the order i suggested to keep costs down unless your grow space is in a place already exposed to the elements (which it shouldn't).

You can def just use an exhaust to work as an intake aswell but be sure to make the inlet bigger than the fan itself. So if the fan is a 6" then use an 8" inlet duct or two 6". I personally use both an intake fan and a vent to help with humidity and take the burden off the exhaust while maintaining negative pressure to assist in total carbon filtering

Thx. Yeah i have a 4" inline fan & pulling air in through a 6" flap. A guy had told me to pull air from outside. Think he thinks im going to purchase ac and other stuff. . He mentioned drawing air from inside the house wpuld affect my hot water tank. It is in the house in the laundry room on the eastside of the house. Grow tent is on the nw corner of house.

 

[Chris Scorpio]

He mentioned drawing air from inside the house wpuld affect my hot water tank.

What!!!!

Yer not sucking in 1000000cfi of air......lol


Think yer fine as we have mentioned so far

 

[Metal Halide]

Thx. Yeah i have a 4" inline fan & pulling air in through a 6" flap. A guy had told me to pull air from outside. Think he thinks im going to purchase ac and other stuff. . He mentioned drawing air from inside the house wpuld affect my hot water tank. It is in the house in the laundry room on the eastside of the house. Grow tent is on the nw corner of house.

Those pesky hydro shop owner.
yeah, good call with the laundry. It's often nice and cool in summer if its tiled and such. get yourself 2 hygrometers/thermometers all in one. One for the laundry and another for inside the tent as references. I use a wireless weather station and monitor from anywhere in the house I may be.

If you're doing Auto's then the flap is fine under 24/7 but if its a photoperiod strain 12/12. Then you gonna need ducting and %100 darkness for 12 hours instead of the flap unless you can %100 guarantee total darkness in the laundry aswell. but that often is much much more tricky depending on your situation. I mean like, I often fall ass over tits in the mud when super stoned and therefore in need of my well lit "Landry".

 

[TurboBucket]

What!!!!

Yer not sucking in 1000000cfi of air......lol


Think yer fine as we have mentioned so far

If your exhausting all your air outside he's correct. You could be pulling all that air down the water heater exhaust, (assuming it's gas fired). Not overly likely to happen if your house is drafty. New construction with a tightly sealed envelope, it's more possible. But unlikely to happen with just a 4in fan on a filter.


So if your 84 in a 72 degree room your 12 degrees above ambient and already at the top of the heat range. If your house gets to 75 you'd be at 87 which is too hot for extended periods without elevated co2.

 

[Chris Scorpio]

Go with that then

 

[No Pain]

Why would you want to bring hotter air into the tent from outside your house???

Vent into the tent from holes at bottom of the tent
Run yer exhaust outside the house or to yer ceiling vents from the top of the tent

Easy peasy

what he said ...

as far as temps and such look up and follow VPD get yourself a laser thermometer to check lst (leaf surface temp) I didn't see you mention what kind of light/lights you are using as different lights have a different effect on leaf surface temp in comparison to ambient temps ..also you didn't mention how many plants you will be running in that tent ..that fan and filter may not scrub all of the stink just so you are aware.
I wouldn't worry about the hot water heater unless it was in the same room …your fan will be pulling air from the path of least resistance ..example from under a door to the adjacent room or a vent in the room for heating and cooling .

 

[RedDirtRay]

Those pesky hydro shop owner.
yeah, good call with the laundry. It's often nice and cool in summer if its tiled and such. get yourself 2 hygrometers/thermometers all in one. One for the laundry and another for inside the tent as references. I use a wireless weather station and monitor from anywhere in the house I may be.

If you're doing Auto's then the flap is fine under 24/7 but if its a photoperiod strain 12/12. Then you gonna need ducting and %100 darkness for 12 hours instead of the flap unless you can %100 guarantee total darkness in the laundry aswell. but that often is much much more tricky depending on your situation. I mean like, I often fall ass over tits in the mud when super stoned and therefore in need of my well lit "Landry".

Oh no. Its on the the opposite side of the house from the laundry room. Grow tent is in the front bedroom on the nw corner. Laundry & hot water tank is on the ne corner. He was saying something about the fan drawing the exhaust from the tank & suffocating everyone in the house. Lol. I got everything set up last night.

 

[RedDirtRay]

If your exhausting all your air outside he's correct. You could be pulling all that air down the water heater exhaust, (assuming it's gas fired). Not overly likely to happen if your house is drafty. New construction with a tightly sealed envelope, it's more possible. But unlikely to happen with just a 4in fan on a filter.


So if your 84 in a 72 degree room your 12 degrees above ambient and already at the top of the heat range. If your house gets to 75 you'd be at 87 which is too hot for extended periods without elevated co2.

The house is almost 100 years old lol. No problems.