How To Build Grow Tent Exhaust

How to Design a Complete Exhaust System for a Grow Tent

When it comes to tiny grow spaces, proper ventilation can make or break the experience. Cannabis plants, like all other plants, require fresh air and sufficient air circulation in order to grow and develop properly. Installing an exhaust system to remove old, stale air and excess heat from your cannabis plants and replace it with fresh, cold air may significantly enhance the health of your plants, resulting in larger, more productive harvests. It is possible that the incorrectly designed fan and exhaust system will considerably reduce the potential and cause system inefficiencies.

As we will see, fan size isn’t only about the number of cubic feet per minute that can be moved (CFM).

Depending on the type of light you use, the pace at which CO2 is supplemented, and even where you reside, the system needs might fluctuate.

Why Fans and Exhaust Are So Important In Your Grow Room

When it comes to tiny grow spaces, airflow is important. Fresh air and excellent circulation are essential for cannabis plants, as they are for all plants. Installing an exhaust system to remove old, stale air and excess heat from your cannabis plants and replace it with fresh, cold air may significantly enhance the health of your plants, resulting in larger, more productive harvests over time. The incorrectly sized fan and exhaust system can dramatically reduce the potential and result in system inefficiencies, among other consequences.

As we will see, fan size isn’t only about the number of cubic feet per minute that can be moved by the machine (CFM).

Light sources, CO2 supplementation rates, and even where you reside may all have an impact on how much energy is required by your system.

Putting Together a Complete Ventilation and Exhaust System

There are a zillion different ways to set up ventilation in a grow room, but they all rely on the same basic components, which are installed in the same sequence. When it comes to small-scale operations, fewer parts are required, but the addition of carbon filters and grow room monitors becomes increasingly vital as the number of plants engaged increases. Most grow tents these days are pre-assembled with a complete exhaust system in mind, which is a big help. From intake to exhaust, these are the important components that you can expect to find in the majority of grow tents, listed in the sequence of intake to exhaust.

These are installed on the intake line to filter out any potentially harmful impurities before they enter the enclosed grow chamber.

Along the bottom of the compartment, there are most likely passive air intake holes (filtered or unfiltered) to be found. Exhaust systems should always be located near the top of the tent, allowing fresh air to be drawn up from the bottom, resulting in a natural line of air circulation.

Although ducting is a fundamental component of an exhaust system, it is worth addressing. Components and particular grow room ducting will be required to link the various portions of the system, according on the order of activities. The greater the length of the ducting, the greater the amount of effort the fans must perform to move the air. The more twists and turns (and the sharper the angles) in the ducting, the more power will be required to pull air through it and out of it. In order to make a 90-degree turn, more force is required than for a 45-degree turn.

  1. One of the most important components of a ventilation system is the interior fans, which are responsible for gently circulating air throughout the grow tent.
  2. Circulation fans are nothing special; they are simply the types of fans that you would use to cool off your kitchen or bedroom.
  3. In most cases, it is responsible for most of the air flow throughout the room.
  4. Inline fans are often better at drawing air than they are at pushing air, which is why they are put towards the end of the line (before a carbon filter if you are including one).
  5. Most light fixtures (even LED choices) generate a large amount of heat for the tiny amount of area they occupy, and this heat must be dissipated by proper ventilation.
  6. Lung rooms are a fantastic answer for this, and the simplest example of one would be a grow tent placed inside a bedroom to accommodate the growing process.
  7. Put a cloth beneath the door and close the window/room as much as you can, and you’ll be OK.
  8. Carbon filters are installed at the exhaust end of the system in order to remove the strong cannabis fragrance from the air before it is released into the environment.
  9. Carbon filters, such as the AC Infinityseries, are available in a variety of duct diameters ranging from 4″ to 10″, with a number of quiet alternatives.

Keep in mind that the majority of the components contribute drag to the system, necessitating the use of a more robust fan (with a greater CFM) to guarantee that the system can efficiently suck air in and pull it out indefinitely.

How to Calculate CFM For Your Grow Tent

When it comes to establishing the proper exhaust and ventilation within your grow tent, you may have observed that there are many different formulas (and views) available online. Following ten years of experience and our own study, we strive for an air exchange rate (also known as a scrub) of once per minute. As you’ll see in the following section, calculating once each minute simplifies the calculation. It is necessary to calculate the cubic feet per minute (CFM), or cubic feet per second, in order to determine the optimum fan size and exhaust needs.

You may use the same recipe for a large room or for a little grow tent; the results will be the same regardless of the size.

Although the CFM calculation is straightforward in and of itself, there are always extra things to consider in a grow room, which will almost certainly raise the size of the fan that is needed.

Never overlook the importance of taking into account the influence of grow lights on your grow room setup!

Happy Hydro’s Simple CFM Calculation

1. Take measurements for the space’s width, length, and height. To find out how many cubic feet there are, multiply the numbers together. The space’s dimensions are its width, length, and height. To find out how many cubic feet you have, multiply the numbers together.

  • The following examples illustrate this point: 112 base CFM plus two HID lights (10 percent) equals 123.2 CFM
  • 112 base CFM with two HID lights and a carbon filter (30 percent) equals 145.6 FM

In order to achieve this final CFM rating, install an inline exhaust fan and ducting of the required size.

  • Because it is rated at 210 CFM, both the 123.2 and 145.6 CFM rated grow tents in the preceding example would function with a 4″ Cloudline T4 Inline Duct Fan System With Temperature and Humidity Controller.

Choosing the Right Size Inline Exhaust Fan for a Grow Space

Before selecting an inline exhaust fan, you’ll want to take into account the following extra specifications:

  • Before making a decision on an inline exhaust fan, you should take into account the following essential specifications.

As soon as you’ve calculated the predicted CFM, taking into consideration all influencing elements such as the ventilation system and the outside environment, round up and seek for solutions that fall inside that range. Inline fans are first and foremost classified in terms of cubic feet per minute (CFM), and it should be simple to distinguish between those rated above and below your grow tent objective. For example, theCloudline S4 has a capacity of 205 CFM, but theCloudline S10 has a capacity of 1011.

The more the CFM, the greater the size of the duct required.

As a general rule of thumb, consider the following:

  • As soon as you’ve calculated the predicted CFM, taking into consideration all influencing elements such as the ventilation system and the outside environment, round up and seek for solutions that fall within this range. Fans for grow tents are first and foremost measured in cubic feet per minute (CFM), so it should be straightforward to distinguish between those rated above and below your desired CFM. A good example is the Cloudline S4, which has a capacity of 205 CFM and a maximum capacity of 1011 CFM. There is a connection between CFM and duct size. The higher the CFM, the bigger the ducting that is necessary to deliver the airflow required. Various duct sizes are utilized by each inline exhaust fan (from 4″ to 10″ and beyond). General guidelines to follow are as follows:

While noise will have no effect on the efficiency or performance of your exhaust system, it may be crucial depending on where you choose to install the grow tent in your house or in your garage. Indoor growth is more noisier than some people anticipate, owing in large part to the requirement for a complete ventilation system. If noise reduction is a concern, look for fans that have silencer components, such as the AC Infinity Duct Fan Silencerseries. Invest in a fan that has a controller, like as theCloudline T6 with Temperature and Humidity Controller, to give you a little more control and flexibility in your grow area.

It is usually preferable to purchase a slightly larger fan with a speed controller than you will really require for the system.

The last thing to consider is whether or not your fan is compatible with a carbon filter if you are utilizing one.

It is possible that a strong exhaust fan will force air through the filter too quickly, rendering the filter useless. Always pick an inline exhaust fan with a lower CFM rating than the filter it will be connected to.

Grow Room Fans and Exhaust Should Never Be an Afterthought

We may forgive inexperienced growers if they add an inline exhaust fan and ducting to their basic arrangement as a last-minute consideration. However, today’s commercially available grow tents, like as the Gorilla Tents, all include the essential openings to accommodate a complete exhaust system. Installation and set up are significantly less difficult because the structure has already been constructed. When you take the effort to calculate CFM and install an appropriately sized fan, filtration, and ducting, you will see an instant return on your investment when harvest time comes around.

Ventilation Ideas for a Grow Tent

A grow tent allows you to convert a piece of your home into a growing space in a short amount of time and effort. Grow tents don’t require much in order to be effective, but they do require light, and certain grow lights generate a significant amount of heat that must be evacuated from the environment. In addition, your tent may accumulate an excessive amount of humidity, putting your plants at danger for mold, mildew, and a range of other ailments. These issues can be resolved by increasing the amount of airflow available.

Grow Tent Basics

Growing in a grow tent is similar to growing in a tiny greenhouse that is housed within your home. Commercial grow tents are generally constructed of a solid frame that is covered with a flexible, water-resistant material. The inner of the cloth is typically coated with a sheen to reflect light onto the plants and encourage them to thrive. Grow tents built from garbage bags, tarps, or plastic sheets may be used practically anywhere as a structure and can be covered with almost anything.

Cut Some Holes

The quickest and most straightforward method of ventilating a grow tent is to cut small holes in the material. Commercial tents normally have this done for you, but if you’re creating your own, you may have to perform some hole-punching to get everything to fit. The ventilation holes may be sufficient for tents that use cool lighting such as LEDs or fluorescent bulbs. For ventilation, you’ll need to cut holes in each side of the tent so that air can flow through, bringing in fresh air and exhausting hot, stagnant air from the inside.

Add a Fan

In the event that you have a grow tent with ventilation holes but it is still generating excessive heat or humidity, consider including a fan in the mix. It is not necessary to keep the fan running constantly in the grow tent. Set it to agitate the air in the room outside of the tent while it’s not in operation. This may be sufficient to enhance circulation within the tent, and it may also be sufficient to maintain the proper temperature and humidity levels for the plants within the tent.

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Create a Duct System

Installing an air-conditioning fan in a grow tent that has ventilation holes but is still generating excessive heat or humidity is recommended. At the grow tent, you don’t need to have your fan running nonstop.

You may program it to circulate fresh air in a room outside the tent while it’s not in use. This may be sufficient to promote circulation within the tent, and it may also be sufficient to maintain the proper temperature and humidity levels for the plants within the enclosure.

Build a Marijuana DIY Grow Tent Under $300

In this article, I will demonstrate how to construct a DIY grow tent for less than $300. The goal of my project was to demonstrate to you all that no matter how expensive your equipment is, you can still effectively produce cannabis from seed to harvest. Despite the fact that more expensive equipment may come with advantageous features that might result in greater outcomes, weed has been growing for many years with nothing more than soil, sunlight, and water. This blog article is devoted to individuals who are on a tight budget, who are just beginning started, or who are being stressed out by the long list of equipment and high initial charges.

At the conclusion of this post, you will find links to all of the objects mentioned.

How To Build Grow Tent From The Ground Up

LightingWe will be employing a Vivo Sun 600 watt full-spectrum LED for our lighting needs. This light can illuminate a 33-foot vegetable bed at 32 inches and two 12-by-12-foot flowers at 24 inches, making it the ideal choice for our tent. FiltersTo provide ventilation, we will be utilizing the pre-assembled Vivo Sun fan and filter kit, which is available on Amazon. It includes a 203 CFM inline 4-inch fan with a carbon filter, eight feet of ducting with hose clamps, and a speed controller that allows you to manually regulate the fan’s rotation speed.

  • MonitorsWe will also require a pH and TDS monitor, which will guarantee that the pH and TDS levels in our medium and feeder are maintained at the proper levels during the plant’s life cycle.
  • The first item on the list is an O2COOL 10-inch fan, which will be used to move the air around towards the bottom of the tent.
  • PotsWe will be utilizing five-gallon cloth pots from Vivo Sun, and last but not least, we will require the ACURITE environmental monitor in order to monitor the temperatures and relative humidity (RH).
  • If you’re producing an Autoflowering cannabis strain, you won’t need to worry about setting a timer for it.

Other essentials

You’ll also need the following items to get started:

  • Duct tape made of metal
  • The use of a flathead screwdriver to tighten the duct clamps is recommended. Cutting scissors to cut through the ducting To cut the wire, you’ll need a wire cutter.

Now that we have everything, let’s get started. Let’s get started on the Grow tent.

Installing The Exhaust System

First and foremost, we will be installing the exhaust system on the vehicle. Attaching the 4-inch ducting to the carbon filter using a loosely-fitting duct clip is a good place to start. Using aluminum tape to help seal and keep it in place, attach the hose clamp to the carbon filter to ensure that it is securely fastened in place. Placing the Filter on a Hook The method I’d like to share with you folks is one that will make the procedure of hanging the filter much easier. Dismantle the tent’s top support bars and attach them to the carbon filter first, before putting the tent back together.

Installing and Configuring the Exhaust Fan You may then cut the ducting to size and attach it directly to your inline exhaust fan once you’ve hung the filter.

How you exhaust the air from your room will be entirely up to you and will be determined by your living environment.

It enables them to vent into their attic without the need to drill holes into the drywall or plasterboard.

If ascending into your attic is not a possibility, you may try exhaust via a window or into a separate room. Once the exhaust pipe has been set up, it should be connected to the fan’s exhausting side. It is now complete with regard to the ventilation element of your tent construction.

Hanging The Light

After then, it’s time to put your light up. After you’ve attached the wire hangers, hang it from the top support pole in the same manner as you did with the carbon filter (see illustration). Finally, turn on the light and set the two air circulating fans inside the tent to complete the process. Now switch everything on, and there you have it: a $300 grow tent that will see you through from beginning to end of your project.


Some things I’d still advocate, such as obtaining a humidifier for vegetables and a dehumidifier for flowers, are things I’ve done in the past. There are, however, various methods of controlling the relative humidity in your grow tent that do not require the purchase of additional equipment. I hope you found the article to be interesting. Consider checking out our comprehensive guide on how to grow marijuana at home, which includes tips on how to maximize your chances of success. All of the items that were used in this BuildGrow Tent are listed below.

1/8′′ Adjustable Hangers for Dehumidifiers and Humidifiers

How to Ventilate Your Grow Space

You must have adequate ventilation in order for your plants to flourish. By giving your plants with fresh air from outside your grow tent, you are supplying them with CO2, which is necessary for their photosynthesis. Meanwhile, removing the air inside will help to keep the temperature and moisture buildup under control, avoiding mold and mildew from growing on your plants’ leaves and so hindering their ability to thrive. The extra benefit of refreshing the air within is that it helps to eliminate unpleasant smells.

Essential Grow Tent Parts

Assuming you have previously chosen or purchased your grow tent, this tutorial is equally useful if you are working in a grow room. This is a list of the three most important components that you’ll need to put together while building a ventilation system:

Inline Duct Fan (Active Exhaust Fan)

An inline duct fan, also known as an extractor fan, is a device that is used to exhaust hot and humid air from within a growing chamber or tent. Even little variations in temperature and humidity may have a significant impact on your chances of generating a fruitful harvest. Furthermore, unregulated heat and humidity cause poor growth circumstances, resulting in your plants being unable to absorb water or simply failing to make it through the day. The use of an inline duct fan in your grow room is essential for controlling the climate in your growing environment.

Using an active exhaust fan to draw in cooler air can assist you in maintaining a comfortable inside temperature level.

In ventilation systems with passive intake, inline duct fans also serve as a vacuum, drawing in new CO2 from the outside air and bringing it into the system.

Duct Tubes

Inline duct fans are attached to your grow room using ducting that is clamped or glued in place. The ducting serves as a channel to divert stagnant air away from your grow space. They are typically constructed of aluminum, although they may also be multilayered to provide additional protection against rips. Its size and bends have an impact on the performance of your inline duct fan, but we’ll get into that later.

Carbon Filter

A carbon filter will be required in order to prevent scents from traveling to your garage or closet. This device, which is also known as a carbon scrubber, removes the smell of plants from the air, capturing the odor and neutralizing it. Carbon filters are a must-have for growers that have to cope with very strong odors. They are also used to trap pollen and spores, which helps to keep the air clean for farmers who suffer from allergies or respiratory problems such as asthma.

Typical Grow Tent Setups

A charcoal filter will be required in order to keep scents from traveling to your garage or wardrobe. This device, also known as carbon scrubbers, removes the stench of plants from the air, capturing the odor and neutralizing it using a chemical reaction. The use of carbon filters is a necessary for farmers that deal with very strong odors. They are also used to collect pollen and spores, which helps to keep the air clean for farmers who suffer from allergies or respiratory problems such as asthma.

What Size Inline Fan do I Need?

There are many different sizes of grow areas, and each one requires a particular amount of airflow to be properly ventilated. It is critical for maximum plant growth that stale air within your grow room is exchanged with fresh air from the outside of your grow area. CFM (cubic feet per minute) is the unit of measurement for this number. To determine the quantity of airflow required for your grow room, first calculate the volume in cubic feet of the space. Most grow tent specifications are offered to you in inches; thus, you must convert the size of your space from inches to feet.

This will match the capacity of your grow room, and the needed airflow will be equal to this value in cubic feet per minute, or CFM, as well.

When the dimensions are added together, the result is 72 ft 3 in length.

Keep this amount handy since you’ll need to adjust it to account for the ducting, carbon filter, and any other accessories you decide to install.

Factoring in Accessories

In order to boost your base CFM, you must multiply it by the efficiency percentages of your accessories. Adding components to your grow room, including as ducting and carbon filters, may limit fan performance, which will have an impact on the fan size you require. When it comes to ducting, the quantity and sharpness of its bends play a role in determining the resistance to airflow. As a result, airflow decreases the longer it needs go, making a straighter ducting path more effective. The greater the sharpness of the curve, the greater the severity of the efficiency drop; a 30° bend reduces airflow by 20%, while a 90° bend reduces airflow by 60%!

  • If you are utilizing LED grow lights, you must also take into consideration their heat production, which can raise your necessary CFM by as much as 50%.
  • Because the efficiency of accessories on the market might vary substantially, you can utilize approximated efficiency percentages based on the type of component you are using.
  • This amount is multiplied by the efficiency % of each component to arrive at the final result.
  • Adding in the heat output of your grow lamp (about 50%) gives us a needed CFM of 249 cubic feet per minute.
  • The following is a breakdown of this calculation: Multiplying your base CFM (72) by the percentages of ducting (20 percent), carbon filter (60 percent), silencer (20 percent), and grow light heat (50 percent) of your choosing will provide about the 249 CFM you require.
  • This will let the fan to operate at lower speeds while remaining quieter, as well as providing additional area for future expand space system growth.

Look for inline duct fans that are powered by direct current (DC) fan motors, which are the quietest as compared to alternating current (AC) fan motors. PWM-controlled EC motors are also acceptable in terms of acoustic performance.

How to Manage Grow Space Noise

In order to raise your base CFM, multiply the efficiency percentages of your accessories by the percentages of their efficiency. Fan performance in your grow room will be reduced by the addition of components such as ducting and carbon filters, which will decrease the fan size you require. With ducting, the number and sharpness of the bends play a role in the amount of air that is forced through it. Airflow decreases as distance is traveled, hence the straighter the ducting route is, the greater the airflow performance.

  • Improving the efficiency and airflow of your fans may be enhanced by smoothing out any wrinkles.
  • Due to the addition of these variables to your needed CFM, a high-capacity fan is required to move the predicted airflow.
  • Grow light heat multiplied by component components equals required CFM.
  • This value is multiplied by the efficiency % of each component to arrive at the final figure.
  • Based on this information, we can calculate the needed CFM by taking into account the heat output of your grow light (about 50%).
  • The following is a breakdown of this calculation: Multiplying your base CFM (72) by the percentages of ducting (20 percent), carbon filter (60 percent), silencer (20 percent), and grow light heat (50 percent) of your choosing will provide about the 249 CFM necessary.
  • This will allow you to run the fan at lesser rates while maintaining a quieter environment, as well as providing area for future expand space system growth.
  • The acoustics of PWM-controlled EC motors are also acceptable.
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Grow Tent Ventilation Setup & Exhaust Guide

The importance of ventilation in your grow room cannot be overstated. As a result, poor ventilation is responsible for the majority of cannabis issues and leaf symptomatology.

CO2 concentrations, temperature, humidity, and other factors are all taken into consideration. Cannabis plants are only able to survive under specific environmental conditions. It is at this point that grow tent ventilation and exhaust become important.

Why Your Grow Tent Ventilation Is So Important?

Your grow tent should attempt to emulate the growth conditions seen in nature. And the greater degree of control you have over those circumstances, the better. The most important thing to remember is that ventilation and exhaust are essential. Because of this, your grow tent’s environment is favourable to healthy development, vigorous plants, and abundant yields.

Keep The Perfect CO2 Level For Cannabis

Cannabis, like other plants, need carbon dioxide in order to live. However, when plants are enclosed in a small area, the CO2 in the air will soon be depleted and replaced by oxygen if there is insufficient circulation to the plants. So we’ll have to figure out how to restock it in some way. This means that the cold, fresh CO2-filled air should be drawn into your setup while the used air is expelled out the back.

Control Humidity And Excess Heat

Bud rot occurs as a result of inadequate ventilation. Cannabis plants grow in temperatures that humans would consider to be “comfortable.” That is to say, the temperature should be between 70 and 85 degrees Fahrenheit (or 20 and 30 degrees Celsius) throughout the vegetative stage. Dropping the temperature to roughly 65-80°F (18-26°C) when your plants are ready to blossom can result in higher yields and better-quality buds when your plants are ready to flower. In addition to adjusting the temperature of your grow tent, you should also consider controlling the humidity.

If you do not have an adequate exhaust system, you may find yourself with a moist grow room where mold and fungi will begin to thrive.

Avoids Pests And Plant Diseases In Your Tent

Insufficient ventilation causes Bud Rot. We would consider “pleasant” temperatures for cannabis plants to be optimal. To put it another way, temperatures during the vegetative stage should be between 70 and 85 degrees Fahrenheit (or 20 and 30 degrees Celsius). Dropping the temperature to roughly 65-80°F (18-26°C) when your plants are ready to blossom can result in higher yields and better-quality buds when the plants are ready to flower. The humidity in your grow tent should be controlled along with the temperature in your grow tent.

In the absence of an adequate exhaust system, you may find yourself with a wet grow room where mold and fungus might begin to thrive.

Strengthen Stems

Finally, it’s vital to note that cannabis plants benefit from, and even require, a mild breeze in order to flourish at their ideal levels. This helps to give the stems a good exercise and keeps them from becoming too weak to sustain normal bud growth in the future.

Your stems might get anemic if you don’t have a consistent wind blowing through your grow tent. This can lead to bowing. This, in turn, can hinder the leaves from absorbing enough light to effectively photosynthesize, resulting in a reduction in the ability of the plant to grow.

Ways To Setup A Ventilation System In Your Grow Area

It may be necessary to make an investment and experiment in order to find the optimal ventilation for your ventilation system. Nonetheless, it is a feature of your system that will almost certainly pay off in the future. For begin, there are two different methods to configure your ventilation: passive intake or active intake.

Exhaust Fan With Passive Intake

Passive intake depends on negative pressure to generate passive airflow, which is why it is called passive. Quite simply, you have a fan that is pushing air out of the tent, but there is no fan pushing air in from the other side of the tent. As an alternative, you may install an intake hole that allows new air to enter the tent passively. You can have a single passive intake hole that is approximately three or four times the size of the exhaust hole, or you can have many passive intake holes.

This approach will cut energy use and will be the most effective for the majority of farmers.

Active Air Intake And Exhaust System

An active intake system, on the other hand, makes use of a fan to actively draw air into your growing environment. As a result, there are two fans who are cooperating. One to restrict the air from within the tent from blowing out, and another to keep the air from blowing in from outside the tent. When employing this technique, the size of the intake hole is less critical. Because an intake hole that’s almost the same size as an exhaust hole indicates that your grow tent is ideally suited for an active intake system, you should consider installing one.

The Ultimate Ventilation Setup

The fundamental concept of exhaust systems remains constant. Keeping clean, fresh air coming in while venting out old and humid air is critical for the system to function properly. However, there are other accessories and pieces of equipment that you may incorporate into your setup. The ideal ventilation design will not only keep your crop healthy, but it will also be discrete, resulting in the least amount of noise and aromas possible. I’m going to presume that your setup includes any or all of the following components:

  • The use of rope ratchets for securing your equipment
  • An exhaust fan (we’re going to use a passive intake for this project)
  • A carbon filter is used. Ducting and clamps are used. A deafening silencer
  • A fan that oscillates
  • Grow lights that are air cooled (most types of lights, such as LEDs, generate practically minimal heat and hence do not require inclusion in your ventilation system)

Ducting Your Fans And Accessories

The remainder of your equipment will be connected to your exhaust fan in the stages that follow this one, so pay attention. This will be accomplished by the use of aluminum ducting. Using flexible aluminum ducting, I have discovered that the right mix of price, adaptability, and convenience of installation may be achieved. However, insulated aluminum ducting will also work well if you want stronger duty ducting and have the necessary funds. Check for kinks and creases and smooth them out if necessary to guarantee top performance.

Also, try to maintain your path as short and straight as possible until you are outside the tent and the air is flowing freely. You will have a less efficient system the longer and more roundabout your journey is.

Inline Exhaust Fan

After erecting your grow tent, the first thing you should do is connect your exhaust inline fan to it. However, you should avoid connecting anything to your power source until you’re ready to begin growing. Step inside your tent and attach your exhaust fan to the exhaust hole in the floor of your tent. Hanging your fan from the ceiling of your tent is one option. Connect the fan’s exit port directly to the exhaust hole, or duct it if you find it more comfortable, and then close the fan off completely.

Carbon Filter To Deal With Odor

Setup your exhaust inline fan as soon as your grow tent is complete once it has been setup. Don’t forget to keep everything away from your power supply until you’re ready to begin developing. Exhaust fan should be connected to tent exhaust hole by stepping inside the tent and connecting the two together. Alternatively, you may suspend your fan from the roof of your tent. And either connect the fan’s exit port directly to the exhaust hole, or connect it via ducting if you prefer a more pleasant experience.

Silencer For Extra Stealth

When installing a silencer, it is best to position it immediately after the fan; but, if necessary, you may place it farther down the ducting. It works by muffleing the air coming from the exhaust, resulting in significantly less noise. And they are quite effective. My tent, which is located within the home, has a suppressor placed in it, and the decrease in noise is incredible. I highly recommend it. It also alters the sound style; it moves from being a dreadful whining to a pleasant swooshing that sounds more like wind as a result of the shift in volume.

Connecting An Air-Cooled Reflector (Mostly for HID grow lights)

If you’re utilizing high-intensity discharge (HID) grow lights, it’s extremely probable that your hooded fixture can accommodate ducting. You’ll need to have direct airflow passing through the light’s reflector in order for it to work properly. This will assist you in keeping the temperatures down as well as the light bulbs cool, which is important because HID lights generate a lot of heat. Depending on your reflector and how many additional accessories you have, this can add a significant amount of complexity to your setup.

Starting with your CO2 filter and working your way up to your reflector is a good idea.

Sealing Your Grow Tent To Create Suction

A sealed grow tent guarantees that only air enters through the intake hole and only leaves exit via the exhaust fan when the tent is closed. Your exhaust system will be prone to air leakage and will be extremely inefficient if the seals are not properly installed. Sealing provides a separate environment, allowing you to regulate temperature, humidity, and CO2 levels independently. Additionally, it guarantees that your exhaust system is running at maximum efficiency. Your exhaust fan will generate negative air pressure as a result of reducing air leakage, allowing fresh air to enter via the intake hole.

When used in conjunction with a carbon filter, this will further reduce the likelihood of cannabis scents penetrating your house.

However, if you have tears or pinholes, you may use anything from duct tape to Black RTV Silicone to close them up again.

If your grow room is a do-it-yourself project (such as a closet), you may want to consider weatherstripping the door and sealing any other openings that it may have to keep out the elements.

Check For Air Leaks

To check for air leaks, start by turning on your system and closing your tent from the inside outward. Moving an incense stick about the interior of your tent and observing its behavior can give you a better understanding of its behavior. If the smoke rises straight up into the air, the air is exactly where it should be. To finish, take the incense stick outside the tent and position it near to the intake hole on the other side. If the smoke snakes towards the intake, this is a strong indication that you have accomplished effective sealing and negative pressure in the engine.

Oscillating Fans

Oscillating fans are both inexpensive and quite effective. The process of blowing and spreading air uniformly within your grow tent, while also ensuring that the wind is powerful enough to keep the stems of your plants strong You may use floor fans that are placed in a corner of your room or grow tent fans that are much smaller and clip on to the poles of your tent to keep the heat out. It’s possible to hang it or place it in your room if you’re a bit of a do-it-yourselfer and you have a fan laying around.

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The number of fans you need will depend on the size of your grow tent and the size of the fans you use.

There is no straightforward method of determining how many you require.

How To Calculate CFM For Exhaust Fans

To properly ventilate your grow tent, you must first determine how much fresh air is required in order to guarantee that your plants develop in a healthy manner. You may determine the appropriate Cubic Feet per Minute (CFM) required to ventilate your tent using a formula, which is provided below.

1. First let’s find out your grow tent’s volume

While the height of your grow tent may vary, we’ll use a 4×4 grow tent with a pretty standard 8′ height as an example. (width) * (depth) * (height) = 128 ft 3 (width * depth * height)

2. Calculating Base CFM

The amount of air in your grow tent should be replenished by your inline fans once every two to three minutes, at the absolute least. The following is the formula: 128 feet/3 minutes =64 CFMB However, the temperature and humidity of the surrounding environment must be taken into consideration. If the room from which you’re obtaining the air is excessively hot, add an additional 20% to your calculations. And if you’re dealing with high humidity, increase the percentage by another 40%. In a hot and humid environment like mine, the result might be something like this: 64 (cfm) multiplied by 1.4 (humidity) multiplied by 1.2 (warm climate) Equals 108 Base CFM This implies that in order to adequately ventilate your 128ft 3grow tent, you must exchange 108 cubic feet of air every minute.

3. Factoring In Accessories

Now that you’ve calculated your basic CFM, you’ll need to add in your accessories, which may include ducting, grow lights, and a carbon filter or silencer, among others (where necessary). All of these factors might have an impact on how hard your fan has to work in order to create the ideal growth conditions. For example, any abrupt bends in your ducting will drastically limit the efficiency of the airflow through the system. A 90-degree curve has the potential to restrict airflow by up to 60%!

Even a little bent of 30 degrees will result in a 20% reduction in overall efficiency. If you’re using a charcoal filter to eliminate scents emanating from your tent, add additional 60 percent to your calculations. You can see how these will affect your basic CFM by looking at the following:

Accessories Effect on CFM
LED grow lights 20%
HID grow lights 50%
CO2 filter 60%
Silencer 20%
Ducting 30º Bend 20%
Ducting 90º Bend 60%

If we only had a few bends, a few LED grow lights, and a CO2 filter, we’d be in business. In the end, our CFM formula would be: 108 (base) * 1.2 (lights) * 1.6 (filter) * 1.9 (ducting) = 394 Total CFM Required You will now need to purchase an exhaust fan that can produce this amount of Cubic Feet of air per Minute, depending on the size of your grow tent and the accessories you will be using. Check out the greatest 6′′ inline fans that are capable of performing admirably.

Other Air Flow And Ventilation Tips

It is reasonable to expect some noise from your grow tent because it requires a powerful fan to air it. It is possible to reduce this so that your growth is more subtle and unobtrusive, but it is not recommended. Choose a fan with variable speed settings and a CFM rating that is 25 percent more than your requirements; this will allow you to run it at a reduced speed and so reduce noise. Furthermore, the majority of inline fan types are equipped with noise-reducing capabilities. However, as previously said, you may also connect a silencer to your fan, which will reduce the noise it makes.

CO2 Injection To Increase Yields

Injection of CO2 into a grow tent Plants, as most growers are aware, “breathe out” oxygen while “absorbing” Carbon Dioxide (CO2). While plants do not have lungs, they do have hundreds of small holes on their surfaces known as stomata, which allow them to collect CO2 from the surrounding environment. In contrast to us, they require more carbon dioxide in the air than oxygen in order to maintain optimum health. This invisible gas is essential to the process of photosynthesis, and your plants will “suffocate” and die if they do not receive enough of it.

  • It may even be possible to make your plants more resistant to heat and light by doing so.
  • Trying to get the most out of every situation.
  • Even novices and enthusiasts may get incredible yields in the absence of this.
  • Check out this professional tutorial from CO2Meter for more information on how to get started.

Grow Room Air Conditioner

Despite the fact that it may be deemed unnecessary, an air conditioner may be a worthwhile purchase if you are coping with extreme heat. This is especially true for larger venues. It might be an excellent method of avoiding excessive heat and exerting the greatest amount of control over your temperature. Whether you’re growing in the heat of summer or the cold of winter, your plants will benefit from the right cool breeze and provide you with strong and consistent harvests. You have the option of putting your air conditioning unit on the ground.

It’s also a good idea to put it near an outlet so that any remaining water can be easily drained.

According to this calculator, 5,000 BTU is sufficient for grow tents measuring up to 4x4x8 feet in size. You can compute your specific metrics (be careful to choose the appropriate option) (feet not meters).

Final Thoughts

In conclusion, ventilation is extremely crucial to the health and production of your plants, as you can see. The more the degree to which airflow is left to chance, the greater the likelihood that you will be disappointed with poor yields. There are several methods through which you may exercise control over the ventilation of your grow tent in order to achieve maximum yields. Hopefully, you were able to choose one that best meets your needs. And remember to go back to this post anytime you have any questions.

Best Ways to Discreetly Exhaust Your Grow Tent

While grow tentkits are included with comprehensive assembly instructions, you will still be need to make important decisions about where they will be placed in your house. When attempting to determine the best location for a grow tent, the convenience of usage, garden security, and tent exhaust alternatives should be your key concerns. Figuring out where to vent your grow tent may be quite difficult, especially for first-time farmers. While tent manufacturers have created incredible technology for use within tents, there is little information available on how to properly position your exhaust outside of the tent’s setup.

Grow Tent Exhaust System Basics

Installing an exhaust system that swaps stale air for fresh air on a regular basis is essential for optimal cannabis cultivation in a tent. If at all feasible, you should attempt to exhaust the grow tent as far as possible outside your home. Inexperienced growers often fall into the trap of venting grow tents straight into residential areas, such as beds, which can be dangerous. Because heat and humidity can make your living circumstances rather uncomfortable – especially during the summer – this strategy is not suggested.

  • The majority of tent growers choose to use a negative pressure exhaust system.
  • The AC Infinity Air Filtration Kit, for example, was created expressly for the purpose of being used in grow tents.
  • For more information, see How Slight Negative Pressure and Maintaining a Light-Tight Growroom Can Help Maximize Yields.
  • The Air Filtration Kit from AC Infinity

Use Existing Outdoor Vents

For the most majority of experiencedindoor producers, pre-existing external vents are the preferred technique of draining a growroom or tent after harvest.

Not only are these vents intended for the goal of directing air to the exterior of your property, but you are unlikely to have to undertake any big modifications in order to get access to or install them. Even better, outdoor vents are exceedingly unobtrusive and safe to install.

Laundry Room

If you have enough space, the laundry room is one of the greatest places to set up a grow tent for cannabis cultivation. Apart from having built-in exhaust vents that lead to the outside, these facilities also have water connections and electrical outlets to make life easier. If you want to make the most of your laundry room vent, you may place your ducting such that air is forced directly out the vent that was designed for your dyer. This will almost certainly need the use of a ducting boot that is the same size as your ducting and the vent.

The second solution may also necessitate the installation of a booster fan and a shutter to guarantee that hot air from the dryer does not enter your grow tent.


“Passive vents” are found in areas of your home that are not climate-controlled, such as attics and garages. If you didn’t already know, passive ventilation is the process of exchanging old air for new air without the need of any mechanical devices. It is possible that you have passive vents in your attic or garage if you have seen vents that are exposed to the outside straight from the inside. You have two alternatives when it comes to utilizing passive vents. The first advantage is that you can set up your grow tent in either of these locations and have it exhaust straight through a passive vent.

For the second option, you may make a hole in a wall or ceiling and direct the exhaust from the tent into a garage or attic.

For a garage or attic to be a successful exhausting place, you must guarantee that there is sufficient air movement through these spaces.

When it comes to transporting air out of garages and attics, AC Infinity Airlift Shutter Exhaust Fans are excellent choices.

Different Window Setups

Many cannabis farmers prefer to exhaust their grow tents straight via windows rather than through vents. In all honesty, windows are probably the most handy and popular option for this work because to their convenience and popularity. Window exhaust systems, on the other hand, lack discretion as compared to external vents because they demand you to leave your window open when using them. In addition to this, exposed windows that lead straight to cannabis gardens are considered a security risk.

Finally, because windows are strategically placed around the home, they provide you greater choice in deciding where to grow your plants.

Window Vent Kits

Window vent kits, which are meant for portable air conditioners, are used by some tent growers to ventilate their cannabis gardens. Not only are these kits widely accessible on places such as Amazon, but they are also particularly designed to function with ducting. Even more, window vent kits are unlikely to attract attention because they are often utilized to exhaust hot air from air conditioning systems.

Boarded Windows

Cutting a piece of plywood to the size of the chosen window and painting it black is how you go about creating a boarded window. Open the window approximately 6-inches and attach the black piece of plywood to the whole window frame, covering the entire window frame. Finally, drill a circular hole into the piece of wood that is the same size as your ducting. This hole will serve as a vent for your home. This configuration enables you to position your grow tent near a window without experiencing significant noise leakage.

Summary The use of grow tents for indoor cannabis growing is a handy and cost-effective choice.

When you take into consideration the many exhaust choices, this concept becomes more complicated and difficult to grasp.

They are not only intended to move air, but they also serve to keep your garden safe from intruders who may come in via the open windows.

AC Infinity is the most recognized name in air delivery systems, having designed and developed the most cutting-edge breakthroughs in cooling and ventilation technology throughout the years.

For additional information, please see or contact us.

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