The Best 6 inch Inline Exhaust Fan – Review Of The Quietest For Grow Tents and Rooms

by | Mar 18, 2016

How to Choose the Right Inline Fan For Grow Rooms?

Anyone who’s ever been to a hydroponics shop can tell you that purchasing the right equipment is just as tedious and arbitrary as choosing a shampoo at your local department store. You might have a general idea of what you’re looking for, but you’ll also be bombarded with tons of variations of essentially the same product, most of which do the exact same thing. Whether it’s a 6-inch inline fan, exhaust fan, or vent fan, you’ll most likely end up relying on the recommendations of your hydroponics shop, and you may end up paying way more than what you should have, even for something you really didn’t need in the first place. We know the struggle. But before we can tell you what to buy, you’ll have to know exactly what it is you’re looking for. And to figure it out, you’ll need a basic understanding of how air circulation works.

Did you know? When it comes to growing cannabis inside a building or in a tent, having a good quality inline fan is one of the most important pieces of equipment you need to have. This way you will make sure you have enough CO2 available so your plants can get as much as they need. You also need to make sure that the air doesn’t go stale and is being moved around and replaced with fresh air frequently.

Best Inline Fan Comparison Table

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What is CFM?

Every fan, whether it’s a 6-inch inline exhaust fan or an extractor fan, has a CFM rating, which stands for “Cubic Feet per Minute.” This is basically the amount of cubic feet of air that the fan can move in a minute. Some growers tend to ignore CFM ratings because the primary function of inline fans is to dissipate heat, but that’s only part of what they’re intended to do.

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Understanding Plant Biology

On the leaves of your plants, there are tiny pores called stomata (wikipedia link – opens in new window), which are essentially the breathing points of your plants. The stomata on the leaves function as a way for the plant to absorb CO2 and oxygen while dispersing water vapor as a waste product in a process called transpiration, at which point the plant will draw more water from the roots. The stomata will behave according to the conditions of the plant and its surroundings. With a bright light and enough moisture available through the roots, the stomata will become dilated, allowing for more CO2 and oxygen to be absorbed. As the soil becomes dry, the stomata will close to preserve water, thereby halting photosynthesis. With too much water (overwatering) the stomata will dilate to release as much water vapor as possible, but at a rate that can be dangerous to the plant’s survival and development.

What does all this have to do with inline fans?

As the stomata releases water vapor as a waste product, this waste must be displaced from the grow room (click here for 4’x4′ setup guide) via inline fans. If you don’t extract enough air, the air will become thick with water vapor, your plants will have less access to essential CO2 and oxygen, and photosynthesis will be disrupted. However, if you extract too much air, you’ll also be extracting all the precious CO2 that your plants need to thrive.

Maximize Your Yield – Infographic – https://plantsily.com/how-to-maximize-your-yield-infographic/

Simply put, you need to use your inline fans correctly to find the sweet spot for your air circulation.

Calculating CFM

Did you know?The general rule of thumb is that you want to extract all the air in the room every three minutes for ideal circulation.

This allows the plant to absorb all the CO2 it can while also transpiring excess water vapor. If you base your sweet spot around three minutes, the rest of your calculations will involve basic math. Let’s take, for example, a 10’x10’x12’ room. We need to find the cubic feet of the 3’x3′ grow tent, which is expressed by multiplying the length, width, and height: 10 x 10 x 12 = 1200 cubic feet That’s the amount of air we need to displace every three minutes. But since fans are calculated per minute, we need to divide our cubic feet by three to find out how much cubic feet of air we need to displace per minute, which will be our ideal CFM: 1200/3 = 400 CFM So, for a 10’x10’x12’ room, we know that we need a single 400 CFM fan to extract all the air within three minutes. Although this doesn’t take into account various turns in your ducting that slightly restrict airflow or intake fans that you may have pushing fresh air into your grow space, this is generally going to be in the ballpark of what you’re looking for in your fans. Now that you have a better understanding of CFM ratings, check out this comparison of various 6-inch inline fans on the market:

Reviewing The Best 6 Inch Inline Fans

Product Name CFM Price
Atmosphere S-600 Vortex S-Line Ultra Quiet 6” Inline Fan 347 $$$
Can Max Fan Mixed Flow 6” Inline Fan 334 $$$
Active Air 6” Inline Fan 400 $$ 🙂
Hurricane 6” Inline Fan 435 $$
Yescom HO 353 353 $$
VenTech VT DF-6 240 $ 🙁
iPower Grow Tent Ventilation SET (Filter and Duct Included) 442 $$$

1. Atmosphere S-600 Vortex S-Line Ultra Quiet 6” Inline Fan

Buy Vortex 347 CFM S Line S-600 Fan, 6" via Amazon

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Specs:

  • 347 CFM
  • 66 Watts
  • Double Insulated Wall for Noise and Humidity Reduction
  • Quick-Removal Clipping System

 

Pros

  • Great for small to mid-sized grow rooms
  • Comes with ducting
  • Runs very quietly
  • Great style and design
  • Insulated walls
  • 10 year warranty

 

Cons

  • More costly than other options
  • It can only move air at 347 CFM
  • No filter

 

At first glance, the Vortex S-600 seems like a beast of a machine. A superior build quality and fancy design will certainly turn some heads in your grow room, and may even justify its price tag. But don’t be fooled. You won’t get much more out of the S-600 than most other fans on the market, and despite Vortex’s claims that this is an “ultra quiet” fan, the S-600 is pretty loud. If you’re looking for a quiet inline fan with a decent price tag, look elsewhere.

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2. Can Max Fan Mixed Flow 6” Inline Fan

Can Max Fan 6-Inch 334 Cubic Feet

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Specs:

  • 334 CFM
  • 75 Watts
  • Plastic housing
  • Mixed Flow Blade Design

 

Pros

  • Suited for a medium sized area
  • Airtight housing with a space-saving design
  • Lightweight
  • Low overall lifetime cost
  • Outstanding performance
  • 5 year warranty

 

Cons

  • Noisy at full speed
  • No speed controller
  • Not as powerful

 

Can Fans are very popular these days, and for good reason. They’re relatively light, small, and sturdy. In addition to great design, the Mixed Flow 3-speed controller allows you to switch the speed to meet your growing needs, so you’ll actually be saving power if you don’t always need it to be running at full blast. Of course, if you’re getting a 334 CFM fan when you only need half that, you might as well get a 4-inch inline fan instead.

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3. Active Air 6” Inline Fan

Buy Active Air 400 CFM Inline Fan, 6-Inch via Amazon

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Specs:

  • 400 CFM
  • Metal Housing
  • Durable Ceramic Coating
  • Mounting brackets include

 

Pros

  • Operates very quietly
  • Ceramic coating for durability
  • Thermally protected AC motor
  • Top-notch molded impeller
  • Comes with all the necessary mounting parts and hardware
  • UL-recognized components

 

Cons

  • No speed controller
  • No ducting
  • A little heavy

 

“Could even outperform some 8-inch inline fans” Say what you want about Active Air inflating their CFM numbers, but if you’re looking for a fan that does what it intends to do, Active Air’s 6” Inline Fan certainly does the job. It’s relatively quiet, and could even outperform some 8-inch inline fans on the market when it’s used correctly. The mounting brackets certainly help as well; mounting fans is always a pain, but the brackets make things a whole lot easier.

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4. Hurricane 6” Inline Fan

Hurricane Inline Fan - 6 Inch | 435 CFM | High Performance, Commercial Grade Inline Fans, Quiet Operation - Ventilation Fan - ETL Listed

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Specs:

  • 435 CFM
  • Steel Housing
  • Powder coated finish
  • Mounting Brackets Included

 

Pros

  • Very efficient
  • Noiseless operation
  • Professional quality
  • Durable powder coated finish
  • UL rated components
  • Comes with an 8ft cord

 

Cons

  • Doesn’t include a speed controller
  • Doesn’t include ducting
  • It can withstand up to 104°F

 

Hurricane fans are usually good investments, and their 6-inch 435 CFM model is no exception. The steel housing and coated finish certainly add to the quietness of the fan, and $90 for 435 CFM is certainly tempting when you’re looking for a competent fan for your grow space. The only problem with the fan is how the mounting brackets sit on the housing; you might have a hard time drilling the brackets in with how they’re seated against the housing. But that’s a minor concern for a top quality inline fan.

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5. Yescom HO 353 CFM 6 inch fan

Buy Yescom HO 353CFM Hydroponics Ventilation 6" inches Inline Cooling Duct Fan

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Specs:

  • 353 CFM
  • Extended collar for ducting
  • Moisture resistant
  • Vibration-free

 

Pros

  • Vibration-free operation
  • Easy to install
  • Permanently lubricated ball bearings
  • Can withstand up to 140°F
  • Ideal for hydroponic growing
  • Cost efficient

 

Cons

  • It only includes one bracket
  • No filters
  • A little loud

 

Yescom is a relatively unknown brand in the hydroponics air flow market, but names don’t mean much when you’re looking for fans anyway, especially when you consider that the Yescom claims 353 CFM for $65.95, which is far cheaper than a lot of other brands. Although we can’t promise the fan will be all that quiet, the design itself is pretty solid. The extended collar is similar to the Active Air, and should meet your air circulation needs just as well if you’re not worried about brand names.

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6. VenTech VT DF-6 DF6 Duct Fan

Buy VenTech VT DF-6 DF6 Duct Fan, 240 CFM, 6" via Amazon

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Specs:

  • 240 CFM
  • 37 watts
  • All steel construction
  • Powder coating

 

Pros

  • Offers all of the basics required
  • Lightweight with aluminum construction
  • Works well and quiet
  • Easy to use
  • Lots of CFM
  • Inexpensive

 

Cons

  • Not very durable
  • No accessories included
  • No warranty

 

It’s pretty loud. The VenTech may seem far inferior to the other fans we have listed here based on 240 CFM, but we couldn’t complain with a price tag of about 20 bucks. Granted, it won’t do much for an entire grow room, but if you’re running a stealth box grow with only a few plants, the VenTech VT DF-6 may be for you. It’s pretty loud, but you can’t expect much with such a low price tag. To be honest we do not recommend this fan.

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7. iPower Set : 6Inch High CFM Inline Exhausting Fan + Carbon Filter + Duct Fan

Buy iPower 6 Inch 442 CFM Duct Inline Fan with 6" Carbon Filter

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Specs:

  • 442 CFM
  • Metal fan blades
  • 95 watts
  • Carbon Filter and Ducting Included

 

Pros

  • Comes with a carbon filter and duct fan
  • Made of high-quality steel
  • Good for hydroponics
  • Plenty of options
  • Can operate up to 185°F
  • Highly effective

 

Cons

  • No speed controller
  • No warranty

 

It’s not always a good idea to buy fan and filter combos because you can generally find cheaper alternatives if you buy them separately, but the iPower package is a real deal. Considering you’re probably going to need charcoal filters and ducting anyway if you’re trying to run a 442 CFM fan, the iPower package could be saving you money. iPower is generally pretty consistent with most of their products, so you can bet the filter and ducting are going to be quality products. Big plus – Cotton Pre-Filter cover is included for your filter so you can increase the filter’s longevity.

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8. Growsun 6 Inch 400 CFM Inline Carbon Filter Fan Combo for Grow Tent


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This amazing 6-inch inline duct fan combo from Growsun is specially designed for grow tents to make the most out of indoor yields. At an attractive price, you also get an activated Virgen carbon filter, 25 feet of ducting, 30-yard duct tape, speed controller, durable clamps, and a pair of metal hoop. That makes it a tempting offer for cannabis growers wanting to save their time and money.

Running at 400 CFM, the fan keeps the air odor free and makes the planting environment fresh all the time. This low-noise device comes with mounting brackets for easy installation. Thanks to the speed controller, you can easily adjust the speed of the fan according to your own needs. It’s possible to switch between three settings: Full Speed, Variable Speed, and OFF. According to the manufacturer, this fan can remove 99.5 percent of the volatile substances from the air.

In addition to the 6-inch inline fans, there is also a matching 6″ carbon filter that is 1.5 inches thick for the best results. By cooperating with the inline fans it ensures the stability and safety of your grow room.

As mentioned above, you also get a duct tape that is 30 yards long as well as 2 inches wide. Not only that it sticks well to any metal surface but also involves an environmental water glue for enhanced safety.

Please note that this product fits 56″ x 56″ x 80″, 60″ x 60″ x 80″, and 95″ x 48″ x 80″ grow tents, but you can also use it larger sizes as well. It will get the job done for sure.

Pros

  • Comes with just about everything you need
  • A speed controller is included
  • The fan runs pretty quiet
  • Carbon filter features a good size
  • Can remove almost all smell from the room
  • Reasonable price

Cons

  • The fan tends to slow down a bit after a few months of use
  • It may get noisy after some time
  • Ducting could be stronger

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9. Growsun 6 inch Duct Fan Exhaust Kit Carbon Filter Fan Combo

 


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Growsun is one of the most popular brands in the hydroponic world that has launched a lot of great cannabis-related equipment in recent years. Aside from the inline fans, they are producing a whole host of hydroponic accessories and devices for indoor growing. So you can’t go wrong with such a well-established brand as well as a number of positive customer reviews.

When it comes to the Growsun 6″ Duct Fan Exhaust Kit Combo, you get anything and everything you could ever need to grow marijuana indoors. The package includes an inline 6-inch duct fan, a 6-inch carbon filter, an air ducting, a pair of metal hoop, and a duct tape. So you don’t have to waste your time purchasing each of these components separately, as you get all the necessary equipment in this all-in-one package.

The 311 CFM fans work effectively while being almost noiseless. These inline duct fans are designed to run at up to 140°F. Actually, the ambient temperature goes from -20°C to 60°C, i.e. from -4 to 140 degrees Fahrenheit, which is quite enough for most indoor conditions. A built-in 2-speed motor allows you to adjust its operation in accordance with the growth phase of your plants and inner environment alike.

With regard to the carbon filter, we found it extremely effective in removing odors from a grow room. The manufacturer claims that this 6-inch filter is capable of removing 99.5% of the volatile substances from the air. It is 16 inches long and 1.5 Inches thick.

Moreover, you will also be provided with 25ft Air Ducting and 30-yard duct tape. With all these items, you’re all set to start growing cannabis right away.

Pros

  • Comes with a fabric pre-filter cover
  • Suitable for a small grow tent
  • Works like a charm
  • Very efficient
  • Lightweight
  • Affordable

 

Cons

  • The fan may start making a loud noise after a few months
  • The filter is not of the best quality
  • The foil-type duct isn’t ideal for a grow

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ipower set in work Shopping for fans can be tough, but if you just do the math, you’ll know exactly what you need.

Related Articles:

– best 4-inch inline fans – https://plantsily.com/filters-fans/4-inch-inline-exhaust-fan/ – 4-inch Carbon Filters – https://plantsily.com/filters-fans/best-4-inch-carbon-filter/ – Filters and Fans – All you need to know – https://plantsily.com/filters-fans/