Adequate fans and their placement

[GR33NL3AF]

I'm currently working with 6000w rooms with 2.5 ton mini split system A/Cs. Now, the unit I am working in is an outdated modular unit, meaning weak insulation and no attic, resulting in increased influence from the outside weather. This makes my A/C work a bit harder then normal. In these rooms I run three 18" oscillating wall fans spread out evenly and with 'lights on' my temps offer a minimum 5 degree swing, on hot days more. Here is my layout:

Obviously the side of the room the A/C is on stays cooler and more accurate where the other side generally is warmer, resulting in a difference in feedings and numerous other issues. In the past I added a piece of cardboard where the air flows to avoid it returning to the thermostat and prematurely shutting down. Can I modify my thermostat and run it across the room? What are peoples opinions on the amount of fans needed and their placement?

Additional information; its a sealed room, no air exchange, CO2, 4x8 soil beds, magnum and radiant 8 hoods without glass, ballasts ARE in the room(two digitals, 4 magnetic).

 

[baba G]

I typically do an oscillating 12" air king per light, but 16" prob do a light and a half or so. I'd add one more 16" to that room. I do a 12" air king per light as I don't like the way the 16" let gravity pull them down as they age...

 

[GR33NL3AF]

I typically do an oscillating 12" air king per light, but 16" prob do a light and a half or so. I'd add one more 16" to that room. I do a 12" air king per light as I don't like the way the 16" let gravity pull them down as they age...

Would there ever be an issue with TOO many fans? I'd like to run 4 fans for the canopy, 1 under my C02 for greater dispressing, 1 above the lights, and 1 large box fan under my A/C to push the air..

 

[baba G]

Would there ever be an issue with TOO many fans? I'd like to run 4 fans for the canopy, 1 under my C02 for greater dispressing, 1 above the lights, and 1 large box fan under my A/C to push the air..

I only use the low speed out of the 3 speeds so I feel having a lot of them is fine as they are placed to overlap and make sure no corner is dispersing air slower than the center of the room. AS long as you don't have fan leaves being blown so hard constantly that they can't spread flat and catch light versus being wind blown, than you prob can't overdue it.

 

[baba G]

a fan on the right side on the side of the canopy would disperse hot air into the center and keep that right wall a bit cooler I bet.

 

[rick ratlin]

Love threads like this! Always interesting to see the pros approach to something seemingly so simple.

I run a external thermostat on the opposite side where the a/c is mounted, and like the results. Its an ideal air model with a 15 foot external hook up.

Also, a nice floor vortex fan pushing colder floor air up will keep the room temps more stable. In your picture, that fan would be on the lower wall. This fan is also on the opposite side of the co2 burner, and next to the co2 monitor. I don't really like a lot of air blowing on my burner, just me being paranoid. Wish I could have kept the ceiling fan, but it had to go in the build out due to height issues. I personally place floor model oscillating fans in the corners, all about different heights. Then wall mounts under the a/c, and across from the a/c, both blowing air down on the canopy. I've tried the box fan under the a/c and personally like an oscillating fan better.

Lights off, the fans are all on timers. Wall mount fans and vortex fan cut off totally, and the floor oscillators run one at a time, for 15 minutes in a clockwise rotation. All run on low speed cept the vortex. Room is 10x10. Only 2K, sealed, air cooled lights. Might be overboard or over thought, but it works real nice.

 

[GR33NL3AF]

I only use the low speed out of the 3 speeds so I feel having a lot of them is fine as they are placed to overlap and make sure no corner is dispersing air slower than the center of the room. AS long as you don't have fan leaves being blown so hard constantly that they can't spread flat and catch light versus being wind blown, than you prob can't overdue it.

Awesome! In veg I rotate my speeds in an attempt to thicken/strengthen stalks quick. They're never blowing hard enough to cause wind burn but they flop around pretty good.

 

[washburn4life]

I typically do an oscillating 12" air king per light, but 16" prob do a light and a half or so. I'd add one more 16" to that room. I do a 12" air king per light as I don't like the way the 16" let gravity pull them down as they age...

Love the Air Kings! Way Higher quality fan! I rock the 16" and 18". There the only wall fan, I know of, that will keep chugging away after being on for a year.

I am always changing my speeds around but there are mostly on med-low.

Is the 12" fan better for wind burn when you're close to plants? I mean is the 12" a way softer blow then the 16" on low?

 

[Jalisco Kid]

I prefer to load up on AKing's 20" floor fans. I find just using wall fans you end up stressing the plants and mostly they are just hitting around the top 1/3. I use wall fans just to mix the top 1/3 of the room to move that hot air around. I trim my trees so there is nothing on the bottom branches the last 16" down to 12" at the top. This gives the floor fans a chance to move cool enriched co2 up into the middle of the plants which also moves out stale air and the humidity. Once I build a room I use smoke bombs made to test a/c installs. That way I can watch the air flow in my room. Incense kinda works also. JK

 

[washburn4life]

great idea on smoke in a can for air flow I also bonzi the bottoms of the plant and use Box fans ( I didnt know Air King made box fans, but there probably hella money like all there fans) a good under current and canopy current is key

dub 4 life

 

[Jalisco Kid]

They are not box fans.I paid 85 for them. I have had some running 24/7 for over 5 years. cheap wall fans motors burn up easy,I couldn't leave home running something I have no confidence in. JK