Best Inline Filter Fan Combo For A Grow Room – We Review The Smallest & Largest Fans – Find Cheap Options

Table of Contents

by Oct 6, 2015

Why A Carbon Filter Fan is so Important for Your Grow Tent

A good ventilation setup in your growing room is very important for ideal odor control

Plants breathe and get rid of various unnecessary elements through foliage. When proper ventilation is not provided, the pores of the leaves get clogged, leading to the plant’s weakening and progressive death. If there is a sufficient air movement, the leaves can breathe and the plant will grow happily.

Did you know? A carbon scrubber can completely hide the smell of growing cannabis plants, even really smelly ones!

You would be amazed by the amount of new growers I met neglecting this aspect; when primarily investing a fair amount of money in their first growing equipment, unaware beginners often see it as a secondary priority, and although it is possible to grow healthy plants in poorly ventilated grow tent, the use of indoor grow fans ensures a larger and healthier development leading to a better yield.

Our Best Carbon Filter Fan Combo Comparison Table 2018


iPower 4 Inch 190 CFM Duct Inline Fan with 4" Carbon Filter

- FREE Pre-Filter included
- Multi-Functional


Hydro Crunch 4 inch 100 CFM Booster Fan & 4" x 12" Carbon Filter with 4" x 25ft. Ducting Hydroponic Ventilation Kit

- Odor control for better privacy
- Removes heat from the system


Growsun 6 Inch 400 CFM Inline Carbon Filter Fan Combo for Grow Tent, Fans Speed Controller

- Low Noise
- Removes 99.5% Of Volatiles From The Air


Growsun 6 inch Duct Fan Exhaust Kit Carbon Filter Fan Combo With 25-Feet Ducting and 2 Clamps

- Removes 99.5% Of Volatiles From The Air
- Design with Built-in Adjustable Two Speed Motor


Casolly 6-Inch Inline Fan Carbon Filter Fan Combo 315 CFM Fan Exhausting Carbon Air Filter

- Removes heat/cooling and eliminate the undesirable ill-smelling odors


Introduction To Grow Room Fans

There are various types of fans you may use to maintain your plants in good conditions:

  • The exhaust fan, or extractor, is the central piece of a basic setup. It takes the air out of your grow box, renewing it and helping to maintain a bearable temperature for the plants.
  • An intake fan can be added in some cases, to increase air circulation.
  • A simple fan will always be needed to move the air around leaves and buds.

3 types of grow room fans You may use only an indoor grow extractor fan and a simple fan, they create climatic conditions good enough for most of small to medium sized projects. However, an intake fan for grow tent might be needed in larger areas or in case your lamps create a high heat output. Let’s take a closer look at these three fans.

Grow room exhaust fans, intake fans and simple fans

The exhaust fan: 

  • By sucking the air from the inside, this fan provides the basic air-renewal. It can be used alone, one side drawing in the fouled air and the other one exhausting it outside. The air intake is then passive, the depression created being sufficient enough to create a vacuum effect leading fresh air in your grow box through the intake vent left open.
  • One great advantage of air exhaustion is it also allows to cool down the heat-loaded atmosphere induced by the lamps, especially if you use HID lights (MH or HPS) which are known to greatly increase the temperature when lit-up, and many growers use it to regulate climatic conditions when summer heat related problems show up.
  • It also helps to control humidity in your grow space. If a greater level is needed for seedlings and clones, to much humidity can lead to nasty fungi development in your buds and it should be regulated carefully during blooming stages.
  • There are different points of views when it comes to the amount of ventilation you should provide. Some like to leave the fans on all the time, others prefer to use them only once every hour using a dedicated exhaust fan timer.

There are 3 main types of fans used in grow spaces:

  • Axial Flow: they are the less powerful ones, might be used for tiny areas or in larger projects using low heat output lamps like LED or fluorescent.
  • Centrifugal Flow: those are the best ones. You can find Squirrel Cages or Vortex style models, both are powerful and will last long even when used 24/7. A major inconvenience linked to their use is the loud noise they produce, which increases accordingly to their power and the duct’s length.They are the only type you can use if you need a carbon filter for grow tent.
  • Mix Flow: these are powerful in-duct (inline) mounted fans. They are quieter than the previous ones and can be used with success in small to medium sized projects, especially if your lamps don’t increase the temperature much (LED, CFL, fluorescent tubes). However, they won’t last as long as the centrifugal types and cannot be used along with carbon filters for grow rooms.

1. iPower 4 Inch 190 CFM Duct Inline Fan with 4″ Carbon Filter

Buy iPower 4 Inch 190 CFM Duct Inline Fan with 4" Carbon Filter


With this all-inclusive package, you will get anything and everything you could ever need to assemble a complete ventilation system inside your grow tent. That being said, this lightweight combination package contains a carbon filter, heavy-duty inline fan and flexible ducting.


The heavy-duty 4″ 190 CFM inline fan is made of high-quality 1050+IAV Australian carbon (one of the most absorbent charcoal in the world) to be quiet and low-vibration. Plus, it comes with top of the line UL components for silent operation. Moreover, there is a central hub as well as composite fan blades which additionally reduce vibration and noise.


The eight feet of aluminum ducting means you’ll have plenty of options regarding installation. This uninsulated ducting is fitted with two stainless clamps to get it attached to both the carbon filter and fan. Yet, some grow room configurations with numerous ventilation holes may require additional clamps.


Another thing you will love is a pre-filter. The manufacturer recommends that you replace this filter every six months in order to keep it safe. Note that the filter in question has a 2-year life expectancy.


The only issue related to this product is that the fan is pretty loud when running at a low speed. But, when considering all the benefits you can get from it, this issue is really insignificant.



  • High-end UL components
  • Virgin Australian carbon filter
  • Pre-filter included
  • Quiet running fan
  • Multi-functional design
  • Easy to clean and install



  • It’s skimp on clamps
  • It gets loud when lowering the speed
  • No warranty

Summary: If you are looking for a low-priced mix of fan and filter for your grow room, look no further than this amazing deal. When combined together, these items effectively remove undesirable odors and heat from any grow tent. Aside from being cost effective, it is extremely easy to clean and install as well.

2. Hydro Crunch 4 inch 100 CFM Booster Fan & 4″ x 12″ Carbon Filter with 4″ x 25ft. Ducting Hydroponic Ventilation Kit

Buy Hydro Crunch 4 inch 100 CFM Booster Fan & 4" x 12" Carbon Filter


Fresh air plays a critical role in maintaining a healthy grow room. A high humidity from the moisture in your grow op and water vapor can stunt the plant’s growth or totally destroy your crop. To prevent this, you should set up a good carbon filter along with a powerful inline fan. Even better, go for a combo that includes both the fan and filter.


Hydro Crunch offers a unique combo that consists of 4-inch booster inline fan, 4″x12″ carbon filter and 4″x25′ aluminum ducting. When it comes to the filter, it is designed to effectively eliminate odor and harmful contaminants like airborne particulates and organic compounds. It’s made from high-quality virgin activated carbon and features aluminum construction to weigh less.


The booster fan moves stale air throughout the ventilation system and reduces heat in your grow room simultaneously. It is very quiet yet powerful.


In addition, the package includes 25 feet of aluminum ducting with two clamps. It is fairly easy to install. The carbon filter is fluted on both sides, allowing you to easily attach the ducting.



  • Lightweight (thanks to aluminum construction)
  • Effective at eliminating odors
  • Energy efficient
  • Easy to assemble
  • Large mesh openings
  • Ridiculously cheap



  • A little noisy
  • Minor smell issues
  • Not for huge grow rooms

Summary: If you need a carbon filter, inline fan, and ducting in one package, this is a great deal for you. When combined together, these devices yield optimal odor control. By the way, you get a better privacy too.

3. Growsun 6 Inch 400 CFM Inline Carbon Filter Fan Combo for Grow Tent, Fans Speed Controller

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

Those gardeners looking for an all-inclusive pack will appreciate this amazing exhaust system by Growsun. It includes an inline 6-inch 400 CFM duct fan, 6″x16″ carbon filter, air ducting with duct tape, speed controller, and two metal hoops. Moreover, you will get a pre-filter too.


At 5.5 lbs, the carbon filter is an extremely lightweight option. Due to the fact that this filter is made from Virgin carbon and is 1.5 inches thick, you can be sure that it will do its job well in your grow room. According to the manufacturer, it can remove 99.5 percent of volatile substances from the air.


As for the fan, it also has 6 inches in diameter to be compatible with the filter. This 400 CFM low-noise inline fan comes with mounting brackets, and it is suited for the 56″ x 56″ x 80″, 60″ x 60″ x 80″, and 95″ x 48″ x 80″ grow tents, in particular. When coupled with the carbon filter, it keeps the environment healthy and fresh without unpleasant odor. The Growsun’s fan can be controlled by setting one of 3 speeds – Full Speed, Variable Speed, and OFF.


In addition to the fan and filter, you will also get 25 feet of ducting with clamps and 30 yards of duct tape.



  • Conveniently packaged together
  • Good quality of materials
  • Easy to set up
  • Well designed
  • Durable
  • Affordable



  • Clanky fan – makes a loud noise
  • The controls don’t feel exact

Summary: Everything you will ever need to rig up your grow tent is included in this Growsun package. It includes 400 CFM inline duct fan, fan speed controller, carbon filter, as well as ducting and duct tape. Without a doubt, it’s a great value for money.

4. Growsun 6 inch Duct Fan Exhaust Kit Carbon Filter Fan Combo With 25-Feet Ducting and 2 Clamps

buy Growsun 6 inch Duct Fan Exhaust Kit Carbon Filter Fan Combo


If you are owning a small or medium-sized grow op and want to keep it on the quiet side with regard to odors and noise, then this Growsun combo is an outstanding choice for you.


The 311 CFM fan runs smoothly whilst still being very effective, whereas the 6-inch carbon filter eliminates undesirable odor just fine. Note that the air flow inline fan is equipped with a 2-speed motor. Aside from keeping the air cool, it keeps the environment of your indoor garden free of harmful particles. The filter uses activated Virgen carbon and it features the thickness of 1.5 lbs.


Since the fan and filter themselves are not enough, there is also an air ducting and a duct tape included. The 4″x25′ ducting comes with a pair of clamps to put this system together. The environmental water-based glue sticks pretty well to the metal surface while the components match perfectly, so it is quite easy to assemble them.



  • All-in-one package
  • The fan runs surprisingly quietly
  • The carbon filter is very effective
  • Ideal for small and mid-sized grow tents
  • Great design and style
  • Good bang for the buck



  • Pre-filter is prone to degrade
  • Issues with the power button


Summary: A great ventilation solution for small to mid-sized grow tents or grow rooms. It can be used in the most stealthy grow ops. The combo contains an inline duct fan, carbon filter, air ducting, and duct tape. All of this comes at an affordable price, which makes it a great choice for gardeners on a tight budget.

5. Casolly 6-Inch Inline Fan Carbon Filter Fan Combo 315 CFM Fan Exhausting Carbon Air Filter

Buy Casolly 6-Inch Inline Fan Carbon Filter Fan Combo 315 CFM Fan Exhausting


If you’re trying to remove bad odors from your indoor grow op, then Casolly has the right solution for you. It’s conveniently packaged combo set that can double as fresher or cleaner for your plants. Make use of this environmental-friendly combo and get rid of musty smells in your grow room for good.


The package includes 120V 315 CFM inline fan, 6″x16″ carbon filter, filter belt, pre-filter, aluminum ducting, ducting tape, and a pair of clamps. Air ducting is corrosion proof and temperature resistant to be flexible while protecting the unit from breaking at the same time. Thanks to the great flexibility, it can cut down to any length to fit snugly into every object. You will get 25 feet of ducting along with the ducting tape. The instructional manual is also included, but it’s quite easy to assemble the entire system. It only takes about 15 minutes.


When it comes to the inline fan, it is designed to develop the power of 54W and speed of 2250 rpm. The variable speed controller allows you to adjust the speed according to your needs, i.e. the needs of your plants. That eventually results in the improved comfort of your growing space.


One of the best parts of this all-inclusive ventilation combo is the carbon filter. This odor control filter uses the high-quality 1050+ IAV Australian virgin charcoal to remove purifies and odors from the room. Cleaner air contributes to the better health of your plants and increased yields.



  • Great absorbent effectiveness
  • High-quality Australian carbon
  • Fan speed controller
  • Easy to install
  • Multifunctional
  • Reasonably priced



  • The fan is slightly noisy
  • Not suitable for grow tents with a humidifier


Summary: Are you looking for a multifunctional product that can reduce heat and eliminate ill-smelling odors concurrently? Whether you need it for an indoor garden, grow tent, hydroponic system, or green room, this ventilation combo will fit the bill. It can address any air delivery problem in a quiet and quick manner.

Temperature control Equipment:

  • A Cooltube is a reflector equipped with a glass tube surrounding the bulb and connected to the extractor through an air duct. It allows the exhausted air to pass around the bulb and cool it on its way out.
  • Air cooled hoods are pretty similar to cooltubes but instead of surrounding the bulb only, the glass covers the entire surface of the reflector. They are more expensive and considered as more efficient.

cooltube types

Noise Reduction equipment:

Main problem of all these devices is the noise, it can be loud, very loud. If your setup is located in your house and the noise is annoying or if it’s anywhere else and you just don’t want anyone to notice that never-stopping sound you might consider those items:

  • A noise reduction box, is a simple insulated wooden box in which you place your extractor.
  • A muffler is a device you place as a part of your ducts.
  • Speed controllers for fans are used to reduce the speed and thus the noise created by the device.
  • Noise-insulated ducts.

grow tent Noise Reduction equipment

Match your needs:

Exhaust fans have a CFM (cubic feet per minute) rating. It’s important to get a fan with the correct CFM rating for your size’s space and take into consideration the lamp’s heat output.

Here are some examples:

Room SizeMinimum CFM recommended
2 x 2 x 5.25 ft157
3 x 3 x 5.3 ft166
5 x 5 x 6.6 ft355 (2 lamps)
8 x 8 x 6.6591 (3 lamps)

The intake fan:

Buy iPower 6 Inch 442 CFM Duct Inline Fan Vent Blower for HVAC via Amazon An intake fan for grow tent become necessary when running 2 / 3 lamps or more, and using a big fat extractor to cool the place down. If too much air is being taken out without a fan bringing air in,  fresh air will go straight to the carbon filter, missing the plants on its way up. The intake fan should always be somewhat smaller than the exhaust one so the room is always under some suction. You can use mix or axial flow models for that purpose, or centrifugal ones in really large tents.

The simple fan:

Air circulation is just as important as air replacement and should be provided at all times, especially during the budding phase. All the plants should be moving in a breeze every few seconds. Good conditions can be obtained with large ground fans or smaller oscillating fans. TerraBloom Inline Duct Fan 240 CFM, 6 Inch, HVAC Metal Booster Blower However, they should never point directly at the plants, but rather on a tent’s side or above plant tops. These fans can be pretty noisy as well despite their size, especially clip fans attached directly to your tent’s structure and creating strong vibrations. An air-circulation fan:

  • strengthens the plant stems, making them ready to bear heavy flower tops
  • helps control fungus and pest infestations
  • prevents the creation of hot or cold air pockets

 Best carbon filter

Marijuana has the particularity of emitting that very strong smell we all love. Unfortunately, it’s alsoBuy VIVOSUN 8 Inch Air Carbon Filter Odor Control with Australia Virgin Charcoal for Inline Fan via Amazon easily recognizable and thus exposes us to nosy neighbors and law enforcement agents. There are different ways to get rid of the smell or at least make it difficult to detect, but none is as effective as a good old carbon filter for grow tent, as it is cheap, easy to use and will last for at least a year. You can be surprised by the price difference among different models, as the costs range from around $20 to almost $100. The main difference is the type of carbon they use, as better ones will cause for long lasting results, and the weight. Different shapes are available for the same capacity and one might suit you better than the other, especially if you operate in a small space, so don’t forget to take that into consideration as for an optimal effect the filter must be installed at the top of the grow room, where hot vitiated air rises to and accumulates.

Carbon filter setup

Evaluate your needs

The carbon filter should always have a higher CFM rate than the exhaust fan, to ensure a smooth and continuous unobstructed airflow. A small carbon filter connected to a powerful exhaust fan will result in insufficient air-flow and can cause serious problems to your fan, even leading it to burn. A 6 inch carbon filter will adapt perfectly to most air-cooled setups, as air-cooled reflectors and cool tubes have 6 inches duct outlets. A 4 inch carbon filter on the other hand, will save you money and is a good choice if you use low-heat output lamps like fluorescent tubes, CFL bulbs or LED panels which need no extra-cooling.

Set it up!

As stated previously, the filter must be situated in the upper part of your grow space in order to be fully effective. It is usually placed inside the box, as the primary exhausting part of your ventilation system, but some people place it outside with great results. That’s all folks, I hope you have a better idea of what a proper ventilation system must look like! Don’t forget to check our website regularly for the best up to date growing equipment reviews!

Next Steps:

Now you have purchased your first filter & fan and the only thing missing is:

  1. Buy Grow Tent – you have several different options
  2. Buy growing lights – Read the guide here
  3. Buy cannabis seeds online –

If you are completely new to indoor growing read our guide how to grow weed indoors!

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