Different Types of Grow Fans Explained: Why You Need Them & How to Use Them

As an indoor grower, one thing that should never escape your mind is the ventilation of the grow room. Many indoor growers fail to recognize the importance of proper ventilation to their crops, and this leads to poor returns from their hard work.

Whether you are using grow tents, cabinet room, or any other form of grow-room, keeping a stable environment is the surest way of getting good returns and avoid things like mold or mildew which can ruin an entire crop.

Why Indoor Grows Need Fans

Cannabis plants absorb all of the Co2 available around them within around one minute, which is why you’ll need to set up fans near your plants; they distribute any new air around the grow room so that all of your plants have access to a constant stream of Co2 and so that your plants aren’t affected by stagnant air, which can cause illnesses and humidity.

With just a little extra airflow, your plants will be able to breathe much better, improving photosynthesis, nutrient absorption and generally increasing your plants’ strength; the branches will grow stronger thanks to the slight wind resistance, which means that during the flowering period they’ll be able to grow thicker, heftier flowers.

At the same time expelling the air inside will keep temperature and moisture build-up under control, preventing mold and mildew from forming on your plant’s leaves, inhibiting growth.

Refreshing the air inside has the added benefit of removing strong odors. For more on air circulation and other guides to learning how to cultivate cannabis like a champ, check out our step-by-step guide to learning and growing as a cultivator.

grow room meme

Understanding Most Common Fan Types

A variety of fans exists, and each type serves its purpose. Just buying any old fan without knowing the unique function and grow-specific application of each will leave you wishing you’d done more research.

Below we break down the 5 major fan types (yes, that’s a lot but weed loves healthy air circulation!) in terms of what they’re referred to at grow supply shops as well as their primary applications in the cultivation process.

  • Oscillating Fans: An oscillating fan will move the air throughout your plants. They’re one of the most inexpensive fans available and will help you keep your grow room cool and well-ventilated.
  • Inline Fans: The ideal ventilation system should allow both the warm air to escape and fresh air to enter your grow room. The best inline fans for grow rooms can either push air in or pull it out. To allow both, two fans will be necessary.
  • Outtake Or Exhaust Fans: An outtake fan will act as a vacuum and push the old air out of your grow room. The best fan for grow rooms will constantly be removing existing air.
  • Intake Fans: Intake fans have the opposite task. They draw fresh air from the outside and inject it into your grow room.
  • Booster Fans: You might find inexpensive fans called ‘booster fans’. They’re used to help the air circulate and move along long ducts. These types of fans are add-ons and shouldn’t be used as the main fan of a ventilation system.

All-in-One Grow Solutions

If you feel like you’re getting an information overload with all of the information about fans then maybe a custom-built DIY grow room isn’t for you. Often times it’s much easier to start out with a pre-made grow room kit, or a all-in-one grow tent solution.

These include famous tents from makers like SuperCloset, who have an insanely wide variety of tents in different sizes and configurations, to stalwarts like Gorilla Tents, to fully-automated, internet-connected “smart” grow cabinets like Grobo, Seedo, and BC Northern Lights.

How to Choose the Correct Sized Fan for Your Grow

There are various sizes of grow rooms, each requiring a different amount of airflow to ventilate them.

Exchanging stale air inside with fresh air from the outside of your grow space is vital for optimal plant growth. This figure is measured in CFM or cubic feet per minute. Therefore most devices sold should specifically state how many CFM they are designed to flow.

To find the amount of airflow needed for your grow space, first find its volume in cubic feet. Multiply its length by its width and height. This will equal your grow space’s volume, with the required airflow equal to this figure in cubic feet per minute, or CFM.

Adding components like ducting and carbon filters will reduce fan performance in your grow space which affects the fan size you need.

When it comes to ducting, the number and sharpness of its bends factor into the airflow resistance. This is because airflow reduces the further it must travel so the straighter the ducting route the better.

The sharper the bend, the harsher the efficiency reduction; a 30° bend cuts the amount of airflow by 20% while a 90° bend diminishes airflow by 60%! Smoothing out any wrinkles can also improve fan performance and airflow.

Best Grow Room Fans of 2023

Now that we know what to look for in a fan, let’s go into detail of the best ones available the two most popular categories of fans including in-line fans and oscillating fans, as these are the most versatile fan types for grow tents and smaller indoor home grow rooms.

Best Inline Fans


AC Infinity Cloudline T6 review

This inline fan comes with quality, power, and convenience, making it one of the most popular fans. The fan is compatible with any 6-inch duct and carbon filter.

Featuring an airflow of 351 CFM, it should work with most grow tents. It also comes with an intelligent controller that’s easy to use and designed to make your life easier. In one single screen, you’ll be able to monitor, select, and modify the speed of your fan, from 10 different setting options.

The screen also displays the temperature and humidity of your grow tent. Finally, the timer allows you to set a specific number of day and night hours in your tent.

This aspect is crucial when it comes to optimum growth. This inline fan has been designed to emit very little noise while being energy efficient at the same time.

TerraBloom 6″ Inline Fan

TerraBloom 6 inch fan review

This 6-inch fan has a CFM rating of 395, which should allow proper intake or outtake airflow in a regular grow tent and under normal lighting conditions.

The speed controller displays three settings: low, medium, and high. This won’t only allow you to reduce the airflow when needed, but also the noise level and your electricity bill.

Made of ABS plastic, this inline fan comes in three parts, with a removable central section. This allows for easy cleaning and maintenance. To remove it, simply pop the buckles and spin the central piece in a 30-degree angle.

This fan will operate in temperatures up to 140 degrees Fahrenheit and includes thermal protection. If your grow room accidentally reaches 130 degrees Fahrenheit, it shuts off automatically.

The TerraBloom, while not as feature-rich as the Cloudline by AC Infinity, is still a durable, more affordable alternative if you’re OK with having a few less features for controlling your air movement.

iPower 6 Inch 442 CFM Duct Inline Fan

iPower 442 CFM fan review

This fan is one of the most popular fans used by growers in their grow rooms. The reason why many gardeners across the world prefer this fan is its ability to operate efficiently with minimal noise and vibration.

It contains a permanently lubricated bearing, meaning that as a gardener, you do not have to incur the maintenance cost from time to time.

The iPower brand is kind of like the Coors Light of fans, it’s light, it’s cheap, and it’s got a reputation for being a good harmony between affordability and reliability. At 442 CFM the 6″ offering should be a solid unit for most growers.

This one is easy to install and does not require unique knowledge on the part of the gardener. Also, this fan is capable of boosting airflow for a very long time without experiencing breakages that can slow down your work.

The good news is that this fan does not come in a single size model. The manufacturer has manufactured various sizes to help gardeners of different grow room sizes.

VIVOSUN 6 Inch 390 CFM Inline Duct Fan

Vivosun 390 CFM Inline Duct Fan review

Vivosun is famous for producing world-beating grow room fans and filters so you’ll see the brand mentioned a few times in this list.

While other inline fans, like iPower are more universal in their applications, Vivosun is THE brand when it comes to being renowned for hydroponic products.

The Vivosun 4 Inch 190 CFM fan is a heavy-hitting blower (for it’s relatively compact size) that has a fan speed of 2300 rpm. The airflow efficiently moves to your specific location for optimum ventilation.

The small form factor makes this great for smaller operations where 400+ CFM units are just overkill.

Despite all these features, the device produces only 32db levels of noise. Also, the growing fan comes with the 1050+ RC 48 powerful carbon filter from the Australian virgin charcoal bedstead.

Specifically, this filter helps to get rid of the pungent odor that comes from indoor grow tents and hydroponic grow rooms. When you purchase the kit, it comes with a free pre-filter. Therefore, you don’t have to buy a filter for the first six months or so.

Vortex 347 CFM S Line S-600 Fan

Vortex 347 CFM S-Line 600 Fan review

This fan also comes with great features all meant to enhance its efficiency. Just like other quality fans, Vortex 347 CFM Line S-600 fan comes with a user manual that enables one to easily and effortlessly install it.

Built with double insulated walls, energy-efficient ac motor, silencer to minimize the sound it emits, and many other features. The body of this fan is double-walled and well insulated.

That helps to reduce both the noise as well as condensation. The football shape creates a wind vortex to help the air move greater distances than broader diameter fans with non-tapered openings.

Best Oscillating Fans For Maximum Air Circulation 

VIVOSUN Clip-on Oscillating Fan

vivosun clip-on oscillating fan review

Vivosun has a unique design that features triple spiral fan blades that will keep your plants fresh. The fan is made from sturdy materials. You can simply adjust the direction of the airflow by the use of a shake rod.

Still, the fan has an exceptional 120-degree horizontal range and 180-degree vertical range. These fans are popular because of their modular design, their affordable price, and their reliability.

You can mount this grow tent Oscillating fan on the wall or put it on a stand in a tent. This fan is versatile and convenient by ensuring a thorough circulation of the air within the room.

Overall, the fan is efficient and easy to use; therefore, it favors indoor gardening. With indoor grow operations you don’t need to move around hundreds of cubic feet of air (let the exhaust fans do that).

These oscillating fans are simply to keep the air circulating and for that reason you don’t need insane power or insane blade size/fan diameters.

Hurricane Wall Mount Fan

Hurricane Wall Mount Fan review

Hurricane oscillating fan proves to be reliable and versatile in its performance. It features three speeds settings, namely, low, medium, and high. You can conveniently select the right speed to support plant growth.

Furthermore, the fan gives an option of selecting a 90-degrees oscillation, or you can decide to lock it in a particular place. You can also adjust the fan’s head to direct the. The product is also easy to install, and it comes with a one year warranty.


AFC16 Active Air 16 review

This product is also a good fan for indoor growers. It comes with three-speed settings and can oscillate 90 degrees when operating.

With this, you will have full control of the airflow within your grow room. This fan also has two pull chains. These chains are for easy adjustments of speed and direction that your fan will be blowing.

HerbCEO Final Thoughts

HerbCEO Summary

First, we hope you made it this far and we didn’t bore you to death with our deep dive on fan types. Second, we want to congratulate you, whether you build your own grow room or not, the fact you’re looking to cultivate your own marijuana is commendable.

If you’re looking for commercial fans because you’re looking to start or grow a business, we recommend you check out our “how to start a cannabusiness” resource where we highlight some resources that can make the process easier.

If you’re just an average Joe looking to cultivate for your personal use and maybe for friends, then check out our “getting started growing cannabis at home” guide where, in a addition to fans, we provide a few other tips to help smooth out the whole process for you.

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