Air movement - Circulation (not extraction)

Indoor Growing
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Several sources/people have shown that they don’t use oscillating fans for their air movement, instead they use stationary fans of some sort. They use them in a way that “stirs” the air, or some method like that.

Anybody have good information, suggestions, articles on this? I think greenhouses employ this method.

I think there’s a grower here who does it (can’t remember his name, grows in mapito, calls it “race track” effect or something for the air movement).

But just picture a square room, with a stationary fan mounted in each corner, each pointed at the next corner (eg: in a clockwise direction). This would/might cause a “stirring” effect, like a vortex. That might also do something with the vertical air movement (ie: lifting air from the ground level up the sides of the room, and the air from the sides/perimeter into the center (of the vortex) and back down. What do you think?

I have three inline fans that I was thinking of setting up like this. Top down view, eg: 10x10 room. Fans mounted at near ceiling height. One mounted in the center of a wall, blowing straight across. Two others mounted on opposite wall, to the “left and right” of the air stream of the opposite fan, blowing straight across. Might this cause two little “stirring” zones? Or just a nice mixing amount of turbulent air instead? haha.

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Blue objects are inline fans. Grey square is portable ac (which also blasts high speed air in any direction from straight across (level) to straight up (vertical). Green objects are canopy.
I also planned on doing it like this because the two fans on that one wall will be effectively “cooling” the leds that are hung above the canopy.

What do you think about that, guys?
(I used to basically have an oscillating fan, up high, on either side of where that singular fan is mounted in the diagram, oscillating. They’re a bit of a pain to maintain.

I want to achieve well mixed air (rH, CO2, temp) to reduce areas of microclimates (keep the air flowing between plants and leave etc., and have some air flow in and around the lights.

@eskobar (Just remembered it’s you with the mapito race track air).

Thank you.

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I use stationary fans and I like to have one below and above the canopy but given the choice I’ll take below the canopy.

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I’d look into PC fans, I bought 5 pcs for 25$, with a 10$ PSU and a 14$ fan controller from china, I have two of the fans on the lights to keep them cool, and two fans for general airflow. It’s very nice that they are very quiet and small, which allows you to exactly place them where you want, either hang them with tiewraps or put them on a scrognet.

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As for the airflow itself, I like to imagine my tent as a PC, move the air from the inlet towards the outlet fan, and try to minimize “hot pockets”.

Edit: what I’m trying to say is you can try to do both: help your exhaust fan, and keep the air in the tent moving in a way that is healthy for the plants.

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Early in the season the single high fan does the job when the swamp cooler is running, by the time the space is filled that no longer works so I turn on the oscillation. The 2 small fans down low move the air towards the back wall once the plants are tall enough, they are unused until flowering.

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I use two stationary fans in my space.
One above the lights, which is moving the hot air away from the unit (as I have passive heat sinks on the LED light.) This also circulates the heat and helps maintain a steady temp throughout the whole environment.
The other is just above the canopy blowing across, corner to corner in a square tent.
Ideally I’d have one below the canopy too, but I’m growing in a tiny space so dont have room in the tent for another.

:v:

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I hang a tower fan horizontal and aim it over the canopy. You can kind of see here. If they get really bushy, I can add a fan to the other side that blows underneath the foliage. Highly recommend this method for cost, coverage, and simplicity.

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“Hey I got’n idea…how 'bout we fill a pop tart with nasty meat.” Haaawt Pawkiiiiit.
Sorry.

But yea, thanks for the suggestions.
Note: I don’t have an exhaust fan, sealed room. I don’t think pc fans are going to cut it for a 10x10x8.5 room.

Nice! I like it. Cool space too, man. What are the dimensions of that space?

I also thought about the two fans (from my diagram) or an additional two fans (because I want those two up top for the lights) down below canopy to help with the build up of transpiration/canopy area environment.

Few good points in here: https://www.youtube.com/watch?v=n-5dyULMuJA&list=TLPQMDEwNTIwMjQRBqRCLcYwdw&index=1

I’ve been playing with this idea for a while too. I’ve seen several people mention it, and I brought it up in a thread somewhere too. But I couldn’t find a “quality” tower fan, or one I thought was a good option. Also there were some “window”/horizontal fans as options. Even a tower model that’s actually meant to be optionally used horizontally. I worried about these tower fans being used hortizonally as well, because of the bearings etc., they’re not “meant” to be used in that orientation.
The maintenance on these “residential” fans (oscillating, tower oscillating) is a bit of a pain. I’m re-oiling that bastards all the time. The plastic is poor quality, I have two great fans who’s “mount’s” or stands just broke from nothing. I’ve spent too much time repairing and repurposing them.

But I love the ideal of a horizontal “curtain” of air, too.

Thanks guys, appreciate the ideas.

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On a larger scale commercially, we landed on using four large stationary fans about 25% down the wall on each wall. The idea was to move the air in a vortex and it gets sucked down to the middle. Saw really good movement all over. They had to maintain a really nice canopy though because airflow beneath the canopy was only okay. The four worked really well though. I use two oscillating together in my 4x4 though. Both against the same wall but opposite corners.

For their rows, they just had one fan blasting each row across the canopy/light level. Seemed to work well enough but was awfully rough

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Nice.
I wonder if some of the “leaf serration” damage I saw is partly due to oscillating fans blowing right on plants a little too much (causing symptoms, or adding to them, like potassium or something).

Thanks.

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For the diagram shared, you nailed it ^^
Generally you push to the carbon filter, all fans turned to this point.

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10x7…a work in progress.

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You don’t need a hurricane just a flow.

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So, the middle fan in the diagram was already installed when I posted. It’s a 10" inilne.
I just tried putting one of the fans for the opposite walls (all fans are mounted to the ceiling (well to a piece of wood then to the ceiling)). But, because I have the light so high, it and the light are on the same “plane”, so I can’t move the light fixture along its mounting rails (left and right, not up and down). Not only that, it would have to be mounted above the light’s height if I want to be able to move the light.
The other two inlines are only 6", by the way.

I don’t want to lower the light fixture, but I might have to.

I love it. I wish I had that. Looks great. Is each plant roughly 2 to 3 feet in diameter, or what? No lights, just sun?
What are those grey machines? AC, Heatpump, GeoThermal something?

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Thanks, I enjoy it, those boxes are swamp coolers, they work great on the west coast in the dry air…cheap to run.
Looking forward to this season.

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The plastic oscillating fans (most if not all) seem to be just made to die crap. The ones I’ve been using, and loving (because the blade design moves air very well and far), and maintaining(!) are still dying, despite my taking care of them.
Does anyone know of any quality brand fans suitable for our uses. Something durable, with longevity, that if one takes care of them (maintains them) they’ll last years, and years, and years? I don’t care if it’s oscillating or not, in fact I might prefer them to not be.

I’ve been taking apart mine to re-oil them, replace/improved the felt that holds the oil, replaced dead oscillating motors (type of oscillaiting fans that have a separate motor for the oscillation function), etc. Lot’s of work.

I’m thinking of this one, for example. But it looks rather bulky, with it’s deep mounting arm…

How those two fans doing?

What type?

What brand(s), and type?

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Hurricane. Look at most of the nice commercial grows you see in photos, a majority of the fans you will see are Hurricane brand. The 18" fan in my photos is currently on it’s 3rd season of running continuously for 6 months, no issues beyond cleaning.
There is a 12" hurricane in my tent, much better than a 6".

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Hmm. Hurricane, ok. They are a common one for “growers” indoor gardens aren’t they. I passed on a wall mount model of hurricane a couple months back on a good sale. Thought they were known to not last.
Ok, cool.

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I bought two window fans that each have two fans with an intake/exhaust function on each one. Each is in an opposite corner of the tent, facing the other’s direction.

One is aimed straight across the top of the canopy and tent space. It helps push risen warm away from the top and to the other side of the tent.

The other double fan faces it but is mounted beneath the canopy. It not only catches and diffuses some of the warm air by “pulling” it over from the “push” fan, it almost pumps significant air across the underside of the tent.

This drives cooler, wetter air across the lower portion of the tent, where is it sucked upward to the opposing fan again.

AC and humidity are both below the canopy, in the two remaining empty corners. Heat comes out the center top.

Why double window fans? Because on top of that vortex configuration above , I can choose a forward or reverse motion on each of the four fan blades, depending on what I want my air to do.

For ~ $60 bucks, four fans that do all of the above.

Good luck!

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@eskobar is who you’re referring to about the “race track reference” … he can definitely answer stuff like this @Nitt

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I had a hurricane and that thing was out in 6 months… meh :pensive: I had a small 1 though

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