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A good grow tent is only as great as its fan. While you might have the perfect grow tent and light setup, you will need sufficient airflow to keep the air evenly distributed throughout the tent.
A grow tent fan setup will help keep mold away from your plants and give you a better yield. Today we’re looking into everything you need to know about buying the best fan for your growing setup.
Benefits Of A Grow Tent Fan
When growing cannabis, you need optimal airflow to keep your yield as high as possible. Without the best fan with your plants, you might be left with weaker strains, dying plants, and a lot less product than you could have had.
Grow tent fans do more than just manage airflow, though. They can also help calibrate the temperature and humidity, and replenish the carbon dioxide levels.
Let’s have a look at why you need a grow tent fan.
Airflow And Oxygen Levels
Cannabis growing in nature will always have a breeze about them. The gentle (and sometimes harsh!) pressure against the plants helps them to grow a more robust stem and branches. This aids healthy growth over the entire plant.
Plants also need plenty of oxygen to ensure that they grow properly. A fan ensures that your plant always has access to clean and fresh air.
All plants need carbon dioxide to live and grow, and this is exactly the same for cannabis. As grow tents are a closed-off environment, the carbon dioxide levels within are quickly depleted and absorbed by the plants.
The cannabis will then turn this CO2 into oxygen and throw that back into the atmosphere.
Without a fan, the carbon dioxide will not be replenished and therefore the plant will die.
Due to this, your setup needs to have a two-way circulation so that cool air can get into the tent while the hot air can be removed.
Control The Temperature
This might be a little obvious, but a grow tent fan can also control the temperature inside of it. If you’ve ever grown cannabis before, you’ll know that keeping the temperature at the exact right degree is incredibly important.
The sweet spot is between 70 and 80 degrees Fahrenheit.
Along with a thermometer, you will be able to use the fan as a way of keeping the temperature just right.
Grow tents tend to get rather warm due to the heat being emitted from the grow lights. A fan can counteract this when it gets too warm.
This is especially important when you’re using HID lights since these can get super warm and quickly heat up the inside of your tent.
Don’t think that you won’t need a grow tent fan if you have a heater, though. While you might not need the fan to control the temperature, you still need it to replenish the fresh air.
Mold And Pest Control
Despite the fact that a grow tent is a controlled atmosphere, there can still be plenty of fungus and mold spores that get into it. The same can be said for pests such as spider mites and gnats.
All of these things will affect the growth of your cannabis negatively, so you want them under control as quickly as possible.
Luckily, here is where your fan can come into play. A fan will give you more control over the heat and humidity within your tent, so you can alter the conditions to avoid mold and fungus.
Since the pests thrive on mold and fungi, a fan will also help prevent these unwanted creatures from showing up!
Pests can be extremely irritating to get rid of from your grow tent, so prevention is incredibly important. Your grow tent fan will keep this as simple of a task as possible.
Choosing Your Grow Tent Fan
Your setup will need both a fan and an exhaust inline fan to remove used air from the tent. Here we’re going to look at five of the best fans to improve airflow and create an optimal growing condition for your cannabis.
In the next section, we will look at exhaust inline fans. But for now…
Seville Classics UltraSlimline 40 in. Oscillating Tower Fan With Steel Intake Grill – Best Oscillating Fan
This tower fan is perfect for anyone looking for a decent sized fan with great airflow. Based on the reviews and specifications, this fan is ideal for almost every grow tent setup.
The oscillating feature on this fan can span up to 75 degrees, covering every inch of your grow tent with ease.
Due to the size of this fan, it’s best for grow rooms or larger tents. The footprint is small, so it won’t get in the way, and it is quiet while working.
There is a built-in timer to make your life easier, and it can save on electricity. This also makes it simpler to keep your grow tent at the optimal temperature without constant readjustments.
It also comes with a remote control so that you can control the fan even outside of the tent. Talk about convenience!
- Very quiet operation, only operating at 58 decibels on the highest setting.
- Remote control included
- Fits medium to large grow tents and rooms.
- Built-in timer setting.
- Some users found that it clicks while oscillating.
VIVOSUN Patented 6 Inch Clip On Oscillating Fan – Best Small Oscillating Fan
It was like this fan was designed to be used in a grow tent. Maybe it was… Anyway, it comes with a clip so that you can attach it to any pole with a diameter between .59 inches and 1 inch.
The clip is sturdy enough and won’t slide down the pole, and the fan oscillates so that it can reach every plant in your tent.
The range of motion is decent, both vertically and horizontally. The horizontal range is 90 degrees for this fan, and the vertical range is 120 degrees! There’s no doubt that this fan will suit a wide range of grow tent setups, so you can be sure it’ll work well for you.
- Oscillating feature to reach all corners of your tent.
- Secure clip for poles.
- Two speeds.
- Adjustable both horizontally and vertically.
- a 6-inch fan might not be big enough for larger tents.
- Some customers complained that the clip was backward, although this seems to be fixed in newer releases.
Lasko 2535 52″ Space-Saving Pedestal Tower Fan With Remote Control – Best Tall Oscillating Fan
If you’re looking for a tall oscillating fan to tower over your cannabis plants, then this is a great option. It’s powerful and can distribute clean air across the entire span of your tent, so that the clean air can float down onto the plants.
Thanks to the narrow body of this fan, you can fit it into even the tightest of spots. This allows you to make the most of your space! Plus, the rounded base prevents it from tipping over onto your plants.
This fan also benefits from a built-in timer that shuts off the fan whenever you program it to.
Again, it comes with a remote control and an LED display so that you can change the settings from outside of your grow tent.
- Incredibly tall standing at 52 inches tall.
- Comes with a remote control and LED display.
- Built-in timer.
- Customers have complained about a clicking noise when it oscillates.
Honeywell HT-900 TurboForce Air Circulator Fan – Best Budget-Friendly Fan
With a height just below 11 inches, this fan is the definition of a small yet mighty design. The blades have been specifically engineered to generate great airflow from each of its three settings.
Speaking of the three settings, you can use these to find which speed is optimal for your grow tent setup.
This fan is decently quiet and provides you with almost no white noise. That makes sense when you see that it’s marketed up to 25% quieter than similar models on the market. Again, this is a great option for most grow tents.
We especially like this fan for people looking to improve their growth setup on a budget.
- Three speeds to choose from.
- Up to 25% less noise is produced compared to similar models.
- Affordable and budget-friendly.
- Powerful despite its small size.
- Made with lower quality materials.
Hurricane HGC736520 Classic Series Clip Fan – Best Cheap Clip Fan
Another small clip fan, this model from Hurricane weighs under two points with a span of 6 inches across its blades. It’s small but powerful and is excellent for small to medium sized grow tents.
This fan has two speeds to choose from, and this is easily adjusted with the switch on the back of the blades.
The highest setting is able to produce 306 CFM and 2350 RPM, which is impressive for such a small and budget-friendly fan.
This fan might not have been made specifically for grow tents, but it is more than capable of covering a 4 x 4 tent without any issues. The mourning clip also extends to a 2-inch width, which is perfect for fitting around the tent poles.
This fan does not oscillate and has a limited range of motion, making it only suitable for smaller tents. Still, it’s a good choice if you’re on a budget and need a fan quickly.
- Can be adjusted through tilting motion.
- Easy to use and mount.
- Very portable and easily moved.
- Clip might not be the best quality.
Choosing Your Inline Fan
Now that you have your grow tent fan, you’ll need an inline fan. These are used as an exhaust from your tent, removing the hot used air away from your plants. They can also be used for intake, too.
Here are our favorite five inline fans for grow tents.
iPower 4 Inch 442 CFM Inline Duct Ventilation Fan – Best Overall Inline Fan
iPower wasn’t messing around with their brand name, as it perfectly explains what you can expect from this inline fan! It is a super powerful model, offering 2460 RPM and 190 CFM. This is a perfect form of ventilation for a small to medium sized tent.
You’ll be pleased with the quality of this inline fan, with its build quality being sublime. It is built from durable ceramic and coated to make it even more reliable. The bearings are constantly lubricated, so you will not have to worry about any additional maintenance.
Thanks to the fluted design on both ends, you can attach this fan to ducting very easily. The fan blades are quiet, too, so don’t worry about being kept up all night. They run at around 50 decibels, which is quieter than a refrigerator.
If you want to control the fan’s speed settings, you’ll need to purchase the control separately. Without this control, the fan might be a little too powerful for smaller tents.
- Super powerful.
- Reliable and durable design.
- No maintenance needed on your part.
- Speed controls sold separately.
Hydrofarm ACDF6 Active Air 6″ Inline – Best Quality Inline Fan
Hydrofarm is a brand that is known for its tools to help growers of cannabis in their journey to creating a better growth setup. So, you know that this inline fan is perfect for the task you want it to do, which is keep your cannabis plants alive.
This inline fan also comes with a mount and the hardware needed to mount it. The housing is ceramic and coated to make it more reliable. The brackets on either side of the exhaust ensure that you can fit it within minutes.
The speed reaches 400 CFM, making this a good fan for tents of all sizes. However, to reach lower speeds for smaller tents, you will need to buy the speed control that is sold separately.
This inline fan does come with a slightly higher price point than the others we’ve looked at today, but the performance and quality of this fan more than makes up for the cost.
- Made from UI recognized parts.
- Offers high power output.
- Bearings are permanently lubricated, so no extra maintenance needed.
- Motor is thermally protected.
- Speed controls are sold separately.
- Some customers have found it to be louder than advertised.
VIVOSUN 6 Inch 440 CFM Inline Duct Ventilation Fan – Best Performance Inline Fan
This 6-inch fan comes with an output of 440 CFM and an impressive 2450 RPM, meaning that this fan would be ideal for ventilating all sizes of tents, even super large ones.
This machine is sturdy and small, being able to fit into 6 inch vents without an issue. It includes dual flanges so that you can attach it to the ventilation ducts, as well as other pieces of equipment like carbon filters.
This fan weighs 10 pounds, so make sure that you have the correct ventilation to hold it up. It comes with an attached mounting bracket, so you can easily secure it onto a wall or ceiling.
One thing we liked the most about this fan is its noise reduction. There are plenty of features within it to keep the noise level at a minimum. In fact, the overall noise level is just 40 decibels! That is quieter than a lively conversation.
Still, if you need it to be even quieter, this fan is easily fitted into a silencer.
Another great thing about the VIVOSUN 6 Inch is that it comes with the variable speed controller attached to it and therefore you don’t have to spend any more money on a separate purchase.
- Comes with the variable speed controller.
- Simple to install anywhere.
- Quiet operation.
- Durable and great quality.
- Some customers found that the variable speed controller didn’t make much difference.
TerraBloom 4″ Inline Fan – 100 CFM – Best Budget-Friendly Inline Fan
This fan is a compact one with a small size, but don’t let that fool you. It comes with an impressive performance at 100 CFM, which is good for miniature and small grow tents.
The six-foot pre-wired grounded cord is good for all areas of installation as you shouldn’t have an issue reaching it to your intended outlet.
This fan weighs only 1.7 pounds, making it super easy to move around and place anywhere within your ducting.
Some customers have found a number of issues with this fan, but we found the build quality and output to be well worth the cost. It is a great supplement for your ventilation system, and we found no issues with it!
Plus, the 12-month warranty gives you peace of mind with your purchase that your money is protected, should anything go wrong.
- Great value for money.
- a 6 foot cable reaches any output.
- 12 month warranty included.
- If you want to change the speed, you’ll have to buy the controller separately.
Tjernlund M-6 Inline Duct Booster Fan – Best Inline Fan For Lots Of Humidity
Our final inline fan is one that suits a high humidity temperature best. The output is impressive at 460 CFM, so lots of clean air will be flowing into your tent as the told air is dragged out.
Humidity is an issue for many reasons, such as mold, pests, and not being the ideal conditions for your cannabis plants.
Another fan weighing in at 10 pounds, it’s not the lightest on our list. However, it does some with all of the necessary equipment to mount it to the ceiling or wall around you.
With the fan operating at 120 V / 125 W and a maximum current of 1.1 amps, this fan is great for anyone worried about energy efficiency.
The unit is already pretty quiet to begin with, but you’ll also get a strip of isolating foam in your package should you want to use it. You can also use this for a more snug fit after installing it, which will prevent any noisy vibrations.
- Durable and sturdy casing.
- Efficient with its usage.
- Built in the USA with mostly locally sourced materials.
- Not the best customer service
- Speed control needs to be purchased separately.
How Powerful Does Your Inline Fan Need To Be?
When choosing your grow tent fan, it is imperative that you choose one that will aid you in providing fresh air to the entire tent. Otherwise, you’ll have some plants that are not being supplied with the correct amount of fresh air, which might kill them.
Thankfully, there is an easy way around this. All you need is to work out the Cubic Feet per Minute (CFM) that is needed for your tent. Let’s look at how you can do this.
Work Out The Volume Of Your Tent
Everyone’s grow tent will vary in size, you can work out the volume with this formula:
Width x depth x height = volume
Let’s take a 4 x 4 foot grow tent as an example here. These often have a height of 8 feet. The formula would look like this:
4 (width) x 4 (depth) x 8 (height) = 128 feet3
Find The CFM
CFM stands for Cubic Feet per Minute, so you can use the volume we just found for this next part of the equation.
Your inline fan should replenish the air in your grow tent once every two to three minutes. So, here’s what the next equation looks like:
128 feet3 / 2 minutes = 64 CFM
But what does this mean? It means that you will need to exchange 64 cubic feet of air every single minute within your tent to properly ventilate the entire grow tent space. This is otherwise known as your Base CFM.
Consider External Factors
With your grow tent needing to include several other pieces of equipment, like lights, carbon filters, ducting, silencers, etc, these are all going to affect the strength of your fan.
For example, sharp corners in ducting will reduce airflow and therefore require your fan to be stronger so that the air has enough gusto to get past the corners.
In fact, a 90 degree bend can reduce your fan’s airflow by up to 60%. Less dramatic bends will cause less reduction in airflow, but still a little.
Carbon filters can also reduce airflow by up to 60%, so be mindful if you’re using one to neutralize odors.
Here’s a list of common accessories that you might use, and how they can affect your ventilation’s airflow:
- LED grow lights: 20%
- HID grow lights: 50%
- CO2 filter: 60%
- Silencer: 20%
- Ducting with 90 degree bends: 60%
- Ducting with 30 degree bends: 20%
Now, back to our example. Imagine that we only used LED grow lights, three 30 degree bends in our ducting, and a CO2 filter. This is what our final CFM formula would look like:
64 (Base CFM) x 1.2 (LED lights) x 1.6 (carbon filter) x 1.9 (bends) = 233 CFM
Now you need to find an inline fan that can deal with this much CFM. Bear in mind that as you fill it with more equipment, you might need to upgrade your inline fan every now and then to make sure that you’re keeping up with your ventilation demands.
Grow Tent Fan Buyers Guide
So, now you know why you must always choose the correct size of fan for your grow tent to keep your plants in their optimal condition. Most tents and setups will suffice with a fan of 6 inches, so this is a good baseline to start with.
However, before you purchase your fan, there are a few things to consider beforehand.
Number Of Speeds
The higher number of speed settings your fan includes, the more control you’ll have over your growing environment. You can either get a fan with adjustable settings, or purchase a variable speed control separately.
As we saw from most of the inline fans, this is normally necessary!
Now that you have a fan with varied speed settings, you can experiment with them and decide which is the most effective for your grow tent.
If you’re opting for a fan with varied speed settings, we also recommend looking at where the adjustable settings are. Some will have the dial at the back of the fan, but what about when you’re mounting the fan so that these aren’t accessible?
For this reason, we love fans that come with remote controls. They’re easier to use, convenient, and you don’t even have to enter the tent to adjust the fan speed.
Additional Safety Features
Grow tents need to be safe and stable for your plants, as well as your home. Fans often come with ETL listings and CETL approvals. These are made from safer parts and a more reliable build so that you don’t have to worry about them malfunctioning.
Of course, with so much equipment in a grow tent, it is always advised to be careful with what you keep on and running. Practice caution when it comes to any fan, as well as other equipment you have in your grow tent.
Ease Of Adjustments
The more control you have over your fan, the better. It allows you to direct the air wherever it most so that all of your plants can benefit from fresh air.
Most oscillating fans will move from left to right, but other more advanced models will be able to move in a figure 8 motion. This provides amazing air circulation to your entire tent.
Fans should be able to be tilted and adjusted so that you can move it around often. This will ensure that your plants never know where the air is being directed from, ensuring that they get a good daily workout for their stems.
Frequently Asked Questions
What Kind Of Duct Should You Have For A Grow Tent?
Inline fans often require ducting to remove air efficiently from the tent. Flexible aluminum ducting is the best, in our opinion, as it’s easy to install and not too expensive. Just make sure that there are not too many bends in your ducting, as this will reduce the airflow.
How Do You Hang A Fan In A Grow Tent?
Most tents will come with poles that you can clip a fan onto, and this will ensure that you get a good angle for your airflow.
Alternatively, you’ll need to get creative if you’re not using a clip on fan. You could use a cord, duct tape, or anything else that will keep it up and in place.
Or you could just buy a tower fan, which would be easier.
We hope that you have found your new grow tent fan in our list of traditional and inline fans! All of the fans we have looked at today are superb quality, although we would recommend a tower fan and an inline fan to remove the used air from the tent.
I’m an avid gardener and cannabis enthusiast. You can usually find me in my garden caring for my plants or at my computer crafting helpful blogs for my readers.