Optimizing Airflow (Vertical Spaces)

Howdy. I have some ideas and questions about airflow in vertical grow spaces. My grow space is about 10,000 sq ft and is filled with warehouse racks which were converted to 3 level grow towers. Grow spaces on the racks are 10’x5’x8’ and have one oscillating hurricane fan each. I want to find something better than these oscillating fans for air mixing. They leave large dead air spots in each grow space. Another thing, the fans are mounted in alternating directions i.e. one row of racks has fans facing North and the next has fans facing south. Should they all be facing the same way?

The ambient air outside the grow RH averages 45-50 for most of the year. I have been using swamp coolers that came with the warehouse with their water pumps turned off as air intakes since mid august. The swamp coolers intake from the roof. The swamp are at the ends of the grow area, directed to blow in. When humidity rises too much, I open loading bay doors and vent while running heaters. This is working fine right now while temperatures are cool, but I’m afraid next summer it will be too hot in here without turning on the swamp cooler water pumps.

Other than the swamp coolers I have 24" wall fans mounted on one wall about 20 feet from the grow racks. They don’t really reach to the grow racks.

Maybe you see where this is going, during this summer we were growing plants during build out and had to run the swamp coolers with water all day for cooling. While this was going on, I constantly was getting PM on my plants. I do not want to have to rely on foliar sprays for treatment, and would rather figure some way to improve airflow and air mixing so that there are not dead air spots where PM can grow.

My thinking is that RH >60% with dead air zones is what I need to eliminate in order to deal with the PM culturally instead of chemically.

Some ideas I have had for fans other than the oscillating fans:
Large PC fans (multiple at different heights) mounted flush with the rack supports, all blowing in the same direction.
Big Ass fans mounted on the ceiling to move air through the whole space
More 24" fans on the ceiling (blowing down or up?)

I’m looking for input with this post. I know on the cultivation side of things generally there is less open sharing of knowledge and more of a pay to play attitude so I don’t expect easy answers. Any ideas or thoughts about what I’m doing wrong please share them. I can test ideas and I can share the results.


1 Like

Do you have ductwork in the facility or do you just have the fans as a means of air ciruclation?

1 Like

You can use industrial fans. We set up a warehouse grow using 6. Just be super careful, it’s like a hurricane, and not directly blowing on plants

1 Like

No ductwork aside from one of the roof swamp coolers is ducted about 15 foot down to be approximately the same level as the 2nd stack grow space.

You could install ventillation pipe with a single large fan and distribute the airflow more evenly. Install a run of pipe for each row in your room.

1 Like

Could also do one for the return.

And make the fan a air handler.

1 Like

What about reverse the flow direction of the swamp coolers? Exhaust instead of intake. Then filter intake air from somewhere else.

1 Like

I would like to try that. I’ll see if it is possible.

Right now we have no return. .There is no AC in the building aside from some offices and our veg rooms which have cooler chillers.

So maybe having an air handler sat up in the roof and ran to ducting running down each row of grow towers? Could work…

I’m going to try vertically oriented fans below the grates that the plants sit on.

Cool, clean, dry air coming in at the bottom then rising up with the heat of the lights then exhausted sounds good to me.

1 Like

Is anyone using De-stratification fans? Called a few manufacturers and they were talking about other indoor grows using their fans and also a few greenhouses.