The 10 greatest inline followers in your development space in 2020

When growing indoors, ventilation of your growing space is extremely important. Since most grow spaces or tents are closed and in confined spaces, you want to overheat your crop without the right inline fan and kill your plants.

Here you will find our top tips for inline fans as well as some important information on choosing a product that best fits the size of your grow room or tent.

10 Best Inline Fan Reviews

1. Hydrofarm Active Air 6-inch inline fan

Hydrofarm manufactures some of the best all-round hydroponic equipment on the market and their Active Air inline fan series are no exception. This 6 inch diameter fan is our first choice as 6 inches is the diameter that most of us use in their ventilation systems. With the price-performance combination it is difficult to beat Hydrofarm.


  • Reputable, trustworthy brand in the industry
  • High CFM for the price
  • Comes with everything you need to assemble


  • Louder than our premium 6-inch inline fan pick

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2.AC Infinity Cloudline S6

AC Infinity's American-made cloudline is definitely a top product at a reasonable price. It is energy-saving and very quiet and is supplied as a plug-and-play unit with speed controller, all mounting accessories and the fan. Precise humidity and temperature sensors help you to set your fully programmable controller to ideal conditions.

But as they say, everything has its price and AC Infinity's price point is significantly higher than that of other fans. It is totally worth the money spent. But if budget is an issue, this can be an issue that you need to save on.


  • energy efficient
  • Much quieter than other 6-inch fans
  • Lasting build quality


  • The price is higher than the average for a 6 inch duct fan

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3.AC Infinity Cloudline T6

Where the Cloudline S6 shines, it really shines. In addition to the speed controller, fan speed controller and other functions of the S6, the fully digital controls can be customized even more. A backup system keeps its memory sharp so that it remembers the custom speed settings you entered. A countdown system and an alarm timer help you keep track of the status. There is an eco mode setting in case you try to reduce power consumption. And even better, the T6 can share its intelligent controller with the older S6 model, so both can work with the same updated programming.

However, there is a problem. The newer T6 model occasionally appears to have malfunctions in the alarm setting and sometimes goes out for no reason. Using the alarm to notify you of an increase in heat or humidity can be annoying. As amazing as the updates are, the S6 is still a better buy for your money, at least until the T6 is upgraded.


  • Temperature and humidity controls included
  • Alarm system on the control
  • Extremely quiet


  • Most expensive on our list
  • The alarm can sometimes be triggered accidentally

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4. Hydrofarm Active Air 8-inch inline fan

A durable, ceramic-coated metal housing forms the frame on which this robust fan is built. Like all products in the Active Air series from Hydrofarm, it consists of high-quality components and is designed for durability. Thanks to the low noise level, this is a refreshingly quiet method for keeping the air flow flowing or releasing excessive humidity.

There is no speed controller in any of the Hydrofarm systems, but they are available for a small additional fee. The only disadvantage of this special 8-inch model is that, as with many hydrofarm fans, rigid lines are to be used. A flexible pipe material is extremely difficult to connect.


  • Quiet operation
  • Reliable manufacturer with a good reputation
  • Supplied with all installation components as a plug-and-play unit


  • No speed controls are included, although they are available at an additional cost
  • Should really be used with inflexible lines

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5.AC Infinity Cloudline T8

I'm not going to say that AC Infinity's Cloudline is for everyone, but for those who want it, it's perfection. The power cord for all Cloudline models has a good length and can be easily installed in attachment rooms or tents. They are manufactured as inline duct fans and can be easily connected to both flexible and rigid ducts.

Like the other models, this is also supplied with all assembly equipment. Probably due to the T6 alarm problems, however, they were changed from a smart controller to a humidity controller in the box.


  • Fan speed fully adjustable from light breezes to strong winds
  • Built in the USA, made to last


  • No longer comes with an intelligent controller – instead has a humidity controller
  • Higher price than other inline fans

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6. Vivosun 8 ″ inline fan

Are you just starting out and need a cheap inline fan for your business? The Vivosun may not be one of the best inline fans on the market, but it's a perfect place to start. Due to its low price, it is excellent value for money for inexpensive installation spaces, especially if you are only looking for an air intake fan.

However, the disadvantages of a low price can bring the experienced user to a standstill. It has a short cable, which makes it difficult to connect it easily. Carbon filtration is not an option because it is not powerful enough to support it. And from time to time, when testing a new device, users have encountered poor engine operation – although they feel they can quickly replace faulty devices.

For someone just starting out, this is a great way to find out what works best in your growing environment.


  • Very affordable
  • All metal construction
  • Works well as an intake fan


  • Not suitable for use with a carbon filter
  • Short power cord
  • Some users have already found faulty engines

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7. Hydrofarm Active Air 10-inch inline fan

Like the other Hydrofarm inline fans we've highlighted, this 10-inch model doesn't come with a speed controller. However, it is still a very reliable inline duct fan like the rest of its class. With a performance of 760 CFM, this is a good choice for a larger room.


  • Reliable, respected manufacturer
  • Mounting bracket included
  • Good quality large fans at a reasonable price


  • Large diameter fan
  • Suitable for rigid cables

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8. iPower 10 "inline duct fan

The iPower fan series is a good series of mid-range inline fans. Not everything is included in a neat package. So if you're looking for more than one fan, this can be disappointing. Extremely naked, it is likely that you have a wired fan in this box and nothing else.

However, the fan usually has a reasonable lifespan and may be a little easier to install for beginners. It's louder than most others on the list, but this may not be a disadvantage if you ventilate an outdoor greenhouse. My biggest complaint with this fan is the composite blades and hub, as I prefer metal, and even that is a minor problem.


  • Grooved at both ends for attaching pipes
  • Can be used with carbon filtration
  • Very reasonable price


  • A bit louder fan than others we've covered
  • Fan blades and hub are made of composite material rather than metal

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9. Hydrofarm Active Air 12-inch inline fan

In essence, everything we've said about this fan series applies to the 12-inch model, except that it's the largest and highest CFM rating of its fan series. Reliable, robust, ceramic-coated and at reasonable prices, they are a good starting point for most people.


  • Well built, good durability
  • The manufacturer is respected and reliable
  • Great price for a large diameter fan


  • Requires rigid cables for optimal use

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10. iPower 12 "inline duct fan

The same advantages and disadvantages apply to the 12-inch fan as to the 10-inch iPower. A little louder than most of the fans on our list, it's still a decent product. It's an absolute must, so don't expect fancy frills. But its corrugated shape is easy to connect to your system, and the price for this fan size is great.


  • The corrugated shape makes it easier to hook into your duct system
  • Carbon filters are available for this fan
  • Reasonable price for its size


  • Composite fan blades / hub instead of metal
  • Noisier than other fan brands

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Choosing the right inline fan

Choose the best inline fan for your CFM needs.

If you grow indoors, control the entire environment. Light, temperature, humidity … and ventilation. While it is important to know which light sources are best for your garden, many growers forget about ventilation and growth effects. The following factors should be taken into account when selecting inline fans.

Why is it important to win inline fans?

Without proper ventilation of the attachment area, you can cause your attachment operation to fail prematurely. The cramped space and the controlled environment of a growth tent or room require prudence and planning in order to achieve high yields.

Inline fans exchange stale air from the system and often pass through several filter layers. For example, odor filters are often connected to ventilation systems to prevent the spread of unwanted odors in the environment.

What is CFM and how do I calculate it?

An important measurement that you see on all fans is CFM (cubic feet per minute). This number relates – you guessed it – to the cubic feet of air per minute that the inline fan you are considering can exchange from a certain area.

For example, imagine that you have an 8 "x 4" x 12 "room. This is 384 cubic feet of space (4 x 4 x 8). Now, let's imagine you wanted all the air in this room once Replace minute with fresh air, you might think you need a 384 CFM rated fan, but you'd be wrong.

It is always a good idea to multiply the cubic feet of your available space by at least 1.33 to take into account any airflow loss due to filters, etc. attached to your ventilation system.

With this 1.33 times multiplier we get a required CFM number of ~ 510 to exchange the air in our sample growth room once per minute. The following factors should be taken into account when calculating your air flow:

Your grow lights

The type of growth light you use has a big impact on your ventilation needs. HID lamps (HPS, MH) run hotter than others (LEDs, CFLs) and thus heat up your tent or room faster, so that more ventilation is required.

As you grow with HID lighting, increase your calculations by 5% for each lamp you operate in your growing room. If your HID lamps are not air-cooled, you should make a setting of 10 to 20%, because nothing will cool your lamps. This means that your ventilation system has to carry more weight.

Coal or CO2 filter

If you connect filters to your ventilation system, you must take them into account in your calculations. Add at least 20% to your CFM calculation if filters are attached to your channel.

Average temperatures

If you are growing in a room that is exceptionally hot right after starting, you should increase your CFM calculations by at least 25% to ensure that you are ventilating properly. If you have a double mess of high temperatures and high humidity, increase that number by about 40%.

Length of your line

The length of your duct can affect how much energy is required to draw air from your growing area. They also increase the CFM required to exchange air at the correct speed when you notice twists and turns in your ventilation setup.

What diameter inline duct fan should i get?

Vivosun inline fanAn example of a Vivosun inline fan with connected cables.

One factor that affects your buying decision is the diameter of the fan. Wider fans reduce the relative humidity of a growth room faster than those with a smaller diameter.

Smaller diameter fans often have lower CFM values, but you still need the right CFM for your room. After calculating your minimum CFM needs, choose the smallest diameter fan that can deliver it. If you want to drive a little higher than necessary, that's fine. However, be aware that this can reduce the humidity.

Other factors to consider

There are many other factors that affect your buying decision when it comes to a fan. Here are some of the most common:

What is the fan used for?

There are two basic uses for a fan: inlet or outlet. The suction draws air into the room, often through a carbon filter, to remove pests or unwanted dust / pollen. Exhaust ventilates air back out of the room.

Most configurations are based more on outlet openings than inlet openings. This is primarily because removing excess heat or humidity is far more common than pushing air into a room. Our recommendations today focus on exhaust gas requirements, although these fans can also be used for intake if desired.

The passive air intake covers most of the growing requirements. When you push air out of a room, more air is naturally drawn in through gaps or gaps. There are also dust, pollen or contaminants that may be floating in the air.

Active revenue, such as using a fan, is usually an expense that most growers do not need unless they try to keep pests or contaminants away from their plants. They can be useful and combined with additional CO2, but it's fine-tuning a problem that isn't required for everyone, but only for the most specialized growers.

Do you need a speed controller?

Speed ​​controls can be nice, but are not generally needed. If your fan is in your desired CFM area, you never really need to adjust it.

If you prefer a fan with a higher output than you need for your room (to possibly have room for future expansion), a speed controller can be an advantage. With the speed controller, you can reduce the CFM value of your fan from its maximum value to the range that meets your current requirements. If you later adjust the performance of your fan, the speed controller will no longer meet the requirements.

Last updated on 2020-02-01 / Affiliate Links / Images from Amazon Product Advertising API

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