Air Circulation…8 Ways to Use Your Fans

Air Circulation…8 Ways to Use Your Fans

15 Jul 2015

Use them wisely and your air circulation fans will be your new best friends.

They don’t cost much but make a big impact on your climate. Here's how you get the best out of yours.

Why Use Them?

Air circulation fans constantly move air so that you don’t get microclimates – where the temperature, humidity & CO2 level throughout your growing area vary.   

  • Reduces chances of mould in hot, humid spots
  • Gives you an even temperature, humidity & CO2 level   

On top of this, air circulation fans toughen plants up by creating an artificial wind. This mimics outdoor conditions where:   

  • Plant stems and leaves move gently in the breeze
  • This forces them to become stronger over time

1. Circulate Your Air


This is the basic function of air circulation fans. A DiffuseAir is by far the best fan for this.

A lot of growers in tight spaces use a DiffuseAir to free up floor space - it hangs from your ceiling.  

If you use an oscillating fans, make sure you don't point it directly at the plants  

air air

2. Point your air circulator fans towards a wall or ceiling

Try not to point them directly at plants – this can dry them out and/or cause windburn.  

If you've got a DiffuseAir, this isn't an issue. Just hang it in the center of a square tent (use multiples in larger areas).  

If you have any other fan, be very careful to place the fan on the floor and blow air upwards, to ensure the temperatures at the top and bottom of your growing area are more even.

Air Air

3. Now and again, move your air circulator fans about 

Unless you have a DiffuseAir, it’s unlikely that the first home you give your fans is 100% perfect. To get complete coverage, rehome them from time to time.  

Otherwise you’ll end up with pockets of static air, which can eventually cause problems.  

4. Don’t think bigger is better

You’d be forgiven for thinking a big air circulation fan moves more air than smaller ones. One big oscillating fan may not reach certain areas in your grow room. Use a combination of smaller supplemental fans to create constant air movement throughout your growing space.  

5. Use clip-on fans to reach nooks and crannies

All grow rooms have awkward little corners. You’ll likely find that these areas are hotter and more humid than others in your grow room.  

The solution’s a simple one – use a 6 Inch Clip-On Fan or 8 Inch Clip-On Fan. They’ll fit just about anywhere. They're also good for the spot cooling of lights and tanks.

6. Use them to reduce problems caused by a high humidity – vital in flowering

If your humidity is too high during flowering, you can get botrytis (bud rot). Air circulator fans will keep the air moving around your fruits and flowers and will help to avoid conditions where bud rot develops.  

Make sure you closely monitor the environment with an Accuread Temperature & Humidity Meter and adjust your fan settings if relative humidity starts to creep up or dip.


7. Use them to cool your nutrient chiller 


Some grow room tools, such as nutrient chillers, give off heat.

You can point your fan directly at them to keep them cool and optimise your performance.

Air Air

8. Direct humidifier mist over the plant canopy 


To do this, point your fan at the mist coming from your humidifier.

This'll ensure the humidifying effect is constant across your growing space.

air air

We hope you have found these tips helpful. For more advice, ask in store, start a live chat or call 0333 003 22 96.

About the author

Paul is our Merton shop manager. If you haven't met him yet, he's as friendly as they get. 

GroWell Hydroponics Merton

Call GroWell Merton:
020 8648 6327