You can’t forget the critical role of air exchange in your grow room, and that’s why we’ve reviewed some of the quietest inline fans for the job.
Sometimes, when building out your grow room, it’s easy to overlook crucial aspects. After endlessly researching grow tents, lighting, and strains, you might think you have all your bases covered.
Think again. When grown indoors, cannabis plants require light, water, and air.
Product Quick Comparison
Can RS6HO High Output Centrifugal Inline Fan
This fan is a sturdy and durable option, built from high-quality German material.
Its manufacturing means it should last a long time, so although it is not the most budget-friendly option, this durability means it may be worth the investment.
Mounting this fan is easy, due to its large and sturdy mounting bracket. This means you aren’t restricted in where you can position the fan, and the fact that this fan requires no assembly to mount it is a convenient factor.
At 440 CFM, this fan is very quiet and spins smoothly, despite its high-power rating. Even at a lower fan speed, this Can-Fan provides a high-power output.
Despite its sturdy design, some customers have claimed that the housing for the motor is prone to leaking small amounts of air.
While this could be a rare issue, it may be worth thinking about as this fan is not the most budget-friendly.
- Made from high-quality German material
- Large and sturdy mounting bracket
- Due to high efficiency, lower fan speed achieve high-output
- Quiet design
- The housing for the motor leaks small amounts of air
AC Infinity Cloudline S6
For a combination of power and quiet, the AC Infinity Cloudline S6 is the perfect choice. It is extremely quiet, even on the highest power setting.
Its quiet noise level, only reaching 32dBA, is due to the use of a Pulse Width Modulated (PWM) controlled DC-motor.
This motor uses less power than standard AC-motors. In addition to its quiet motor, this fan also comes with adjustable power settings, with eight different fan speeds to choose from.
It uses a stator blade and dual hydrodynamic wind cycles, which means it can provide airflow even in more restricted areas.
The airflow measures at 351 CFM, which is ideal for a mid-sized grow room. In order to mount the fan, there are machine and wood mounting screws included to assist with this.
However, this does require some assembly, which may be inconvenient, especially if there is not lots of free space in your grow room.
- Variable settings allow for efficient power consumption
- Incredibly quiet even on the highest setting
- Ideal strength for a mid-size room
- Assembly is required when mounting
TerraBloom 10" Inline Duct Fan
This fan from TerraBloom comes with a brushless EC motor, delivering an incredible 1065 CFM of airflow using a low energy level of only 150 watts.
This makes it a great energy-saving option, as it uses less energy than many of its competitors.
The speed can be adjusted using a controller, which conveniently comes with the purchase.
Speed ranges from 0-100%, and no further humming or noise is created as speed increases.
This makes it a perfect choice if you need to be discreet, but want to make the most of the speed and power settings.
As well as being powerful, this fan can also run for long periods at an optimal level, so you don’t need to worry about it failing you during certain growth phases.
- Significant CFM coverage at low energy levels
- 2-year warranty
- Runs optimally for any duration of time
- Some of the screws are easy to over tighten
AC Infinity CLOUDLINE T6
At 351 CFM, this inline fan from AC Infinity still has a lot of power to give. Its speed can be adjusted using the intelligent controller.
This means the fan can go from silent to powerful, with the quietest noise level of 32 dBA.
The controller also comes with other useful features, temperature and humidity programming, fan speed control, timer, and alarm system.
These are important features to consider having in your fan, as increased humidity can cause mold and fungi, which will damage your plants.
Without proper air exchange, the air quality decreases, and your growth will suffer. Being able to monitor these conditions easily will help you to eliminate any potential hazards to your plants.
- Abundant power for a sub-400 CFM inline fan
- Extremely convenient digital controller
- Lightweight plastic housing
- Trusted well-known brand
- Rated highly
- Dual ball bearings
- 6" duct size
- One of the quietest brands available
- Short product life with some defective models
AC Infinity CLOUDLINE T4
The third AC Infinity inline fan on our list, this 4-inch fan comes with multiple speed settings with a 205 CFM. This gives you the flexibility to adjust the fan’s performance as need be.
Despite the various speed settings, the fan doesn’t hum or make any distinctly loud sounds, which is ideal if you are looking to be discreet with your growing.
It will make some noise, which is hard not to at the highest power setting, but not be so loud as to cause significant disruption.
An added feature of this fan is its lightweight design. It can be easily hung on the ceiling, or on top of a grow tent, which is useful for bigger grow rooms in particular.
Also included is an intelligent controller with temperature and humidity programming, fan speed control, timer, and alarm system.
As well as the above the AC Infinity T4 inline fan has a mixed flow design combined with a PWM-controlled DC-motor for truly quiet and energy-efficient performance.
- Comes equipped with intelligent controller
- Doesn’t hum regardless of the setting
- Lightweight design
- AC infinity is known for their quality & quiet inline fans
- 4-inch model
- 28 dBA
- Not very powerful
- Plastic design of the AC Infinity is not for everyone
- Price could be better for a 4-inch fan
Tjernlund M-6 Inline Duct Booster Fan
This fan does a great job, This is due to its blade design, and with a power output of 460 CFM, this means the fan can run for long periods with no change in performance.
Despite its high-pressure air handling capabilities, this fan does not produce a lot of noise and maintains a quiet level regardless of its power usage.
It is worth noting that the fan is also speed controllable, but the controlling device is sold separately.
For your convenience, it is also easy to mount this fan to the wall, as it includes the appropriate mounting brackets and hardware.
- Efficient blade design blows massive amounts of air
- Made of high-end materials
- The packaging used when shipping isn’t very protective
Yield Lab 6 Inch 440 CFM Duct Inline Fan
Built to be long-lasting, this inline fan from Yield Lab boats powerful air circulation and durable design.
It provides 440 CFM and 2700 RPM, giving you ample airflow regardless of your grow room size.
It is constructed with solid metal, and the housing has a powder coat, making it pretty indestructible compared to other inline fans on the market.
It is a quiet fan even on the highest power setting, but the noise is known to increase after continued use. This is worth considering if you are looking to invest in this particular fan.
The power rating it possesses means that your grow room will be protected from any stale air or pungent odors.
The fan also contains a balanced motor and lubricated ball bearings, which make it longer lasting and smooth running.
A feature of this choice that could save you time and hassle in the long run is its built-in motor fan controller.
This means you don’t need to purchase any extra equipment, and you can simply plug in the fan and adjust the speed at your convenience.
As this is such a heavy-duty fan, one aspect to consider is that it is quite heavier than many 6” models, which could be a problem if you need to transport it or mount it in a hard-to-reach area.
- Heavy-duty inline fan, built to last
- Super smooth bearings result in effortless ventilation
- Saves money with a reliable speed controller
- Heavier than comparable 6” model
Vortex 347 CFM S Line S-600 Fan 6"
Energy-efficiency is a key feature to look for when it comes to choosing a quiet inline fan, and this one from Vortex is just that.
The fan’s quiet noise levels can also be attributed to its energy-saving design, as the double insulated walls inside reduce noise levels to make them as quiet as possible, whilst also preventing condensation.
The fan also comes with a useful speed controller, and it is worth mentioning here that the fan maintains its quiet noise level even at higher speeds.
The compact design of this fan adds to its appeal, and it also includes a quick clip bracket to allow for easy wall mounting.
Depending on the size of your grow room, this feature may be especially useful to help account for every inch of your grow space.
Although it is a quiet, energy-saving fan, the speed controller can affect this. Some customers claim that the controllers are poor quality, and can cause the motors to emit a distinctive humming sound.
This is not ideal if you are hoping to be discreet when growing, as it could cause unexpected bouts of loud noise.
- Conveniently comes equipped with a variable fan speed controller
- Mounts easily
- Surprisingly quiet at higher speeds
- The fan speed controller is poor quality
- The fuse for the motor isn’t reliable
IPOWER 4″ Inch Inline Duct Fan
For a smaller model, at 4”, this inline fan from IPOWER comes with a high CFM rating, at 190 CFM.
It works efficiently and blows air powerfully, despite being compact. The ventilation system is high-quality and also uses an IPOWER carbon filter.
Although this fan does claim to be quiet, due to its composite fan blades and center hub, it is arguably not as quiet as advertised.
These features should reduce the noise level and vibration, but some users have claimed that there is a loud buzzing sound when the fan is on a low power setting.
Quietness should be a priority if you need to be discreet, so bear this in mind when choosing the right fan for you.
- Incredibly built and long lasting
- High CFM rating for a 4” model
- Small enough to be attached with a carbon filter on the ceiling
- The clamps that come with the inline fan are poor quality
- Not as a quiet as advertised
6" Silent Inline Duct Fan, 26W, 188 CFM
With a sleek and contemporary design, this inline fan is designed to exhaust and intake air using 6” ducts, by making as little noise as possible.
At its highest speed, this fan has a sound pressure level of 39dBA, making it arguably one of the quieter options on our list.
It can be used as both and intake and exhaust fan, bringing both fresh air to large grow rooms, and exhausts air in smaller grow spaces that have LED lights.
This means the airflow is efficient, powering at 188 CFM.
Despite claiming to only be as loud as a regular tone conversation, some customers have found that is louder than they expected.
This is perhaps subjective to you and your needs, but if you do find that it is louder than ideal for your situation, then this fan does come with a 2-year warranty.
That peace of mind is good to have when investing in an inline fan, although this choice is quite budget-friendly.
- Contemporary design
- Highly efficient airflow
- 2-year warranty
- Cheap mounting brackets are prone to breaking
- Louder than competing 6” models
What to Consider Before Buying an Inline Fan
As with anything related to growing cannabis, there’s a lot to consider before making any substantial purchases. Knowing beforehand your exact needs will always make your decision that much easier.
In the case of inline fans, they play multiple roles within the grow room, and it’s best to understand how you’ll utilize them first.
Inline Fan Size
As always, size does matter, but only in the sense of how much air will be needed in the grow room. A 10’x10’ grow tent will need a much larger inline fan compared to a 2’x2’ closet space. So, you’ll first need to measure your grow space.
After measuring your grow room, it’s important to visualize where everything will be once the room is up and running with plants.
Every inch of the room needs to be accounted for because it’ll be a disappointment to buy an expensive inline fan that won’t fit.
By visualizing your grow room, you’ll be able to decide if you’ll hang the inline fan outside the room, in the room and on the floor, or in the room and attached to the ceiling. Generally, these are your only three options.
Inline fans come in a broad range of sizes, from 4” to industrial-grade 18”. Such a wide variety of sizes presents growers with many options.
Some may decide to size-up to allow for a smoother transition into a larger room or some may size-down because their grow space won’t let anything more substantial.
This is why it’s crucial to measure and visualize the grow room so you can purchase an appropriately sized inline fan.
Another essential aspect to consider when buying an inline fan for your grow room is its power rating. This is typically presented in CFM (cubic feet per minute).
A simple way to determine how much power is required is by quickly measuring the height, width, and length of the grow room.
Next, multiply these three numbers to determine the total cubic feet of the room. As a rule of thumb, growers have established that 3-minutes is the maximum amount of time that it should take for your inline fan to exhaust all the air in the room.
Therefore, divide the total cubic feet by 3. This should give you a basic estimate of your CFM requirement.
Your CFM requirement will increase as you add additional items to your inline fans, such as ducting, carbon filters, and the heat from grow lights. Once again, it’s important to understand the CFM requirements before you begin your grow operation because it’ll be a disaster if you realize your inline fan is too weak to exhaust hot air efficiently.
Inline Fan Noise
This is usually the most significant factor to consider when buying an inline fan. Unless you’re lucky enough to live in your own house with no one to complain about noise, then you’ll require the quietest inline fan.
You might not think it’s all that important, but once you’re standing next to a 12” inline fan on full power, you’ll reconsider.
Although cannabis is legal in many states, most growers don’t wish to advertise their business.
There are many reasons why growers want to keep their hobby discreet: professional ambitions, family matters, courtesy to others, or just plain privacy.
Luckily, the vast majority of inline fans are incredibly quiet compared to those on the market 5 years ago. Still, it’s important to shop around for the quietest inline fan on the market.
Some inline fan manufacturers go so far as to encase their fans in special housing to decrease their decibel output. Your overall environment will dictate how far you’ll need to go to keep your inline fan silent.
Heat From Lighting
Grow rooms require a high amount of light. This light comes at a cost: heat. The thousands of watts that you throw at your cannabis plants eventually catch up with your grow space by increasing the temperature drastically.
A hot grow room means a slow death for your cannabis crop.
The best Inline fans act as regulators by exhausting this hot air from the grow room. They counteract the heat by bringing in cooler air from another source.
This is why it’s essential to determine your power requirements beforehand, so your inline fan can quickly exhaust your grow space before any heat can adversely affect your plants.
Growers commonly use high-intensity discharge (HID) lighting.
This type of illumination encompasses both HPS (high-pressure sodium) and MH (metal halide) and ranges from 300-watts to 1,000-watts each.
Your choice of lighting will directly impact the power requirements of the inline fan.
Inline fans cool grow spaces down by not only pulling in cooler air from another source, but also by venting the heat through ducting that’s attached to the lights.
Usually, HID bulbs are placed within hoods that boost the light output with reflectors. These hoods are generally semi-sealed, with a glass panel directly below the lamp. Built-in flanges on the sides allow for an airtight connection to ducting.
The ducting is routed outside, or to another room. Whether your inline fan is pushing or pulling the hot air out, it’ll effectively keep the temperature at a reasonable level.
Mold and fungi are every grower’s worst nightmare. Mold is too difficult to spot until it’s too late, and fungus is capable of wiping out your entire stable within weeks.
Humidity is the primary cause of mold and fungi outbreaks, and the best inline fans are the first line of defense when battling a humid room.
First, you’ll need to determine what season you’ll be growing in. Second, you’ll need to understand if the region you live in is prone to high humidity.
The information gleaned from these two factors will give you a great idea of which inline fan is right for you.
When grow rooms aren’t vented properly, the air becomes stagnant and moist. As time increases, so does the possibility of issues such as powdery mildew.
The constant burst of fresh air that circulates through the grow room lowers the overall humidity, thus lessening your chances for contracting a devastating plant disease.
The aroma of cannabis is variable, but everyone can agree that it’s very noticeable. You’ll be hard-pressed to convince someone that you keep a skunk in your house, so you’ll need a method to scrub the smell.
Carbon filters do precisely that, and they come in a wide range of sizes depending on how many plants you’re growing.
Inline fans work in conjunction with carbon filters because they are usually mounted on them. When viewing pictures of grow rooms, you’ll always see a carbon filter attached to an inline fan, or vice versa.
This is because a carbon filter needs an inline fan to pull or push the tainted air through the carbon particles.
The Overall Benefits of Using the Quietest Inline Fans
As you can see, inline fans along with carbon filters and dehumidifiers play an integral role in maintaining the ideal environment in your grow room.
Buying the quietest inline fan will allow you peace of mind while ensuring that your plants stay happy with fresh, cool air.
If it weren’t for the inline fan, you’d spend a fortune on air conditioning costs, thus rendering cannabis growing completely inefficient.
The inline fan’s job is a difficult one. It pulls air from one source and pushes it out to another. In between, it needs to efficiently push air through the carbon filter, ducting, and lighting.
This is why you can’t overlook your inline fan choices. Inline fans can make or break your cannabis crop, so it’s critical that you understand your grow room set-up.
After searching through a vast amount of inline fans, we found that the AC Infinity Cloudline S6 high-output model outdid its competitors in every regard.
This fan is capable of pushing out speeds that are comparable to 10” models of other brands. It’s uncommon to find an inline fan that’s incredibly powerful, well-built, and overall quiet.
The AC Infinity Cloudline S6 high-output model fits the bill in every respect.
As you already know, inline fans play multiple roles in regulating your grow environment. From heat, humidity and air exchange, inline fans are the necessary piece of equipment that’s needed in every grow room.
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