Fan circulation and position in 4x4 tent

koalajesus · Jun 21, 2021

Hello!

Was brainstorming new ideas for my tent setup and I was thinking about clip fans, floor fans, oscillating, etc.

So my main question pertains to fans blowing on the plant itself to provide airflow.

Regarding the position, I almost always see a recommendation for air flow on top of the canopy and flow for the bottom as well. Most of the time, under the canopy is the optional and over the canopy is always needed.

My new setup (and experience with tent pole clip oscillating fans) has led me to oscillating floor fans, but to get one above the canopy, it'd be on a stand much higher than the one at the pot/medium level. Aesthetically, not that pleasing.

So I was wondering if two floor fans pointing up and an angle and oscillating from underneath the canopy would be enough air flow for roughly 4 plants in the 4x4?

Seems silly to make this decision over looks, but that OCD can kick hard sometimes.

Thanks reading!

V256.420 · Jun 21, 2021

You can but this may give you another idea. I recently installed all new LED lights in my tents. I had to adjust where all the fans went and where the new intakes would come from. So I went with 2 incoming 6" passive intakes at the bottom of my tents and 2 fans with specially made holders to fit on the poles blowing towards the output up top. Some pics might explain better.

The fans tilted slightly upwards blowing on the light towards the exhaust which is above and on the other side.

Here is the exhaust which leads to a duct silencer that sits on a fan which sits on a filter.

Overkill a bit for some but I want it as quiet and odorless as I can get it. This pic also shows the passive duct on the bottom from the outside.

Here is a pic from the inside on another tent that shows the passive air coming in. This is the air I use to "blow" over the plants. They get plenty of movement like this so no need for lower fans.

When the tent is closed that air moves plenty.

Here is the special holder I use for the fans.

He makes these replacements for 16, 19 and 22 mm pole thickness

Just some ideas for you to toss around.

Star Dog · Jun 21, 2021

I'd taken down for a photo but you'll get the idea.

the wooden pole (left) with the fan on it fixes in the middle, I've got it oscillating over the lights and it catches the canopy lightly, out of sight on the floor there's another fan facing up to the oscillating fan, the idea is that the floor fan pushes up the cool air coming in through the passives.

Be careful your fan doesn't/can't push/waft air out of the inlets.

koalajesus · Jun 21, 2021

Thanks for the replies guys! Definitely helping me formulate a solution by seeing what others have come up with.

I like the idea of passive intake and the air being pulled through as the "blowing air" for the lower part of the plant. I have some downsides though that has kept me away from passive intake in my setup.

I live the dryer parts of Arizona and so my humidity is terribly low. Passive intake leads to low humidity very fast, seen it get as low as 28% and as hot as 90 degrees with lights at full blast. The ambient room conditions are about 77-79 degrees and 35-40% humidity. I can't extract the air out of this room, leading to outake air being recycled, and heating the room slowly. The higher I get the fans going, the more it would stay hot and just dry up moisture in the air. Was running into this as I started my first grow and found a neat DIY solution.

I closed up the passives and installed an intake fan that hooked up to this 5 gallon bucket I drilled holes in. Inside the bucket is two layers of swamp cooler pads rolled into a cylinder, then a water pump hooked up to a tube that loops in a circle at the top of the pads and holes in the circle.

i wish I had a picture of the inside to describe it better, but I just have this on me. Basically, the water pump pushes water up the tube into a tube ring with water dripping out the holes and onto the pads, then air pulls in, grabbing some moisture along the way, and comes into the tent.
Running this brings my tent conditions to 79 degrees and 52%-55% humidity with full power lights. With lights off so does the pump in the bucket for the water, so air still flows in, but not as much moisture. Roughly 73 degrees and 47%-50% humidity.

A long way of explaining my passive intake issues, but that's what I have going on.

Additionally, I have seen and love the idea of those 3D printed attachments for clip fans to go to poles, but I would think an oscillating fan is needed to prevent wind burn? Just having them stationary instead of rotating seems like it might not do as great. Your pictures speak for themselves though!

Might have to mull things over and revamp my thoughts on what I consider viable.

Star Dog · Jun 23, 2021

koalajesus said:
Thanks for the replies guys! Definitely helping me formulate a solution by seeing what others have come up with.

I like the idea of passive intake and the air being pulled through as the "blowing air" for the lower part of the plant. I have some downsides though that has kept me away from passive intake in my setup.

I live the dryer parts of Arizona and so my humidity is terribly low. Passive intake leads to low humidity very fast, seen it get as low as 28% and as hot as 90 degrees with lights at full blast. The ambient room conditions are about 77-79 degrees and 35-40% humidity. I can't extract the air out of this room, leading to outake air being recycled, and heating the room slowly. The higher I get the fans going, the more it would stay hot and just dry up moisture in the air. Was running into this as I started my first grow and found a neat DIY solution.

I closed up the passives and installed an intake fan that hooked up to this 5 gallon bucket I drilled holes in. Inside the bucket is two layers of swamp cooler pads rolled into a cylinder, then a water pump hooked up to a tube that loops in a circle at the top of the pads and holes in the circle.

View attachment 4928212

i wish I had a picture of the inside to describe it better, but I just have this on me. Basically, the water pump pushes water up the tube into a tube ring with water dripping out the holes and onto the pads, then air pulls in, grabbing some moisture along the way, and comes into the tent.
Running this brings my tent conditions to 79 degrees and 52%-55% humidity with full power lights. With lights off so does the pump in the bucket for the water, so air still flows in, but not as much moisture. Roughly 73 degrees and 47%-50% humidity.

A long way of explaining my passive intake issues, but that's what I have going on.

Additionally, I have seen and love the idea of those 3D printed attachments for clip fans to go to poles, but I would think an oscillating fan is needed to prevent wind burn? Just having them stationary instead of rotating seems like it might not do as great. Your pictures speak for themselves though!

Might have to mull things over and revamp my thoughts on what I consider viable.

I used to have a similar bucket set up with a sonic mister and a small fan to add rh%, the bucket was kept at the optimum height using a smart valve.
My needs for it were limited to a couple of weeks during seedling/clone stage in summertime, even then 50% would be relatively dry for me, it was a novelty to make and didn't get used much, however in your situation it could be useful?
I see your aware of wind burn, its a very real problem ime.

Cool and humid are the issues I deal with mostly, I've found messing around with the angles/speeds of fans can make a worthy difference (1.5/2c) to the temperature and humidity, adding ducting to the inside of the vents can make sure your collecting it with a fan rather than it heading straight for the filter without being pulled through the canopy.

I'm just putting random stuff down that comes to mind, they all make a difference to some degree ime.

SkorpeonDan · 2024-09-09T15:44:15-0600

I have 4x4x8 tent, currently just 4 autos at about 6 weeks and here is my setup:
4" carbon exhaust running constantly to keep air flowing since I'm trying to 'dial-in' temp and humidity better because my VPD climbs a lot daily when lights are on; so besides the 4" exhaust I have four (4) oscillating fans, 2-6" clip-on and 2-4" flat bottom/clip-on.
My 6" are placed so one is blowing just at/above the canopy and oscillating, one 6" is placed oscillating towards/over/above the light to remove heat, a 4" is using a magnet through the floor screen to bring in outside air and blow across bottom center between the plants and the last 4" is above all others and just below the inline carbon exhaust but on the opposite corner of tent from the exhaust. Zero dead spots and it's that final 4" fan making sure the last breezes crosses the heated air above lights to the exhaust of the tent. This may seem like overkill but nothing is swaying hard causing damage and it helps me keep temp/humidity where I want it and the higher VPD during the day isn't adversely giving issues to the plants and I believe it's because of the air flow they now have. All fans are running constantly, exhaust at 10 and smaller oscillating fans (all 4) run at half speed, I'll adjust if I need to if plants show signs of anything but truth is, once I placed all these fans, the plants started jumping in good healthy growth.

joesoap2013 · 2024-09-09T16:43:28-0600

I have a clip on but not a fan of them they are loud
I'm thinking maybe getting a desktop fan bungee cord have it tied to the bar on the tent ceiling
Did have mine at light height blowing the warm air down
Have it right under the net atm
Have done this before ..like the branches are right in the line of the fan and don't want to be there they will stretch up past the net
I used to do this with hps growing I did think you could manipulate the plant using the fan that way
But I defo will have the fan out of the road when the tents full ..thats a yield decreaser having it at canopy level bids should be growing there

Fan circulation and position in 4x4 tent

koalajesus

Active Member

V256.420

Well-Known Member

Star Dog

Well-Known Member

koalajesus

Active Member

Star Dog

Well-Known Member

SkorpeonDan

New Member

joesoap2013

Well-Known Member