How to Set up a Grow Tent Ventilation System: Step by Step Guide

Whether you're growing 1-2 plants in a short 3'x3' tent in your closet, or you're cultivating 10+ plants in a giant 10'-20' tent in your garage - you cannot overlook the importance of an optimized grow tent ventilation setup.

Without the essential components all working together in unison, your plants won't have the ideal climate to reach their full potential. The worst-case scenario, though, is plant-related problems from excess heat and humidity - like powdery mildew.

A proper ventilation setup for grow tents can seem complex - but it doesn't have to overwhelm you any longer. We've put together a detailed, step-by-step guide on how to set up a grow tent ventilation system.

Down below, you'll find invaluable insights into the importance of your ventilation setup for grow tent growing, you'll learn which components are required to make this system work, and we'll explain how to piece them together to perfection. The end result? A perfectly optimized climate that encourages healthy plant growth. Your hard work will be rewarded come harvest day as you chop down heavy, potent plants! Let's start with a quick overview of what the grow tent ventilation system is.

What is a Grow Tent Ventilation System?

Chances are, you're already somewhat familiar with what a grow tent ventilation system is - and that's why you're here to gain a deeper understanding. Simply put, a grow tent ventilation system is a setup of several pieces of equipment that work together to create an ideal growing environment for your plants. The system pulls in fresh air, regulates the temperature and humidity, and eliminates any unpleasant smells - all while ensuring your grow room climate is managed separately from the rest of your home.

When growing outdoors, mother nature regulates the temperature and humidity for you - a natural breeze keeps your plants dancing, while ambient CO2 levels are high enough to give your plants all they need. But when growing indoors, the onus is on you - the plant parent - to provide the ideal temperature, humidity, and CO2 levels to your plants.

This sounds like a tall order - but it's actually not quite as complicated as you think. There are just a few essential components - an intake fan, exhaust fan, circulation fan, and carbon filter. You'll also need a fan speed controller - ideally with a thermostat - to automate the system. In this article, we'll show you how to put all these pieces together and get your grow tent ventilation system up and running in no time!

But before we dive into the nitty-gritty of how to set up a grow tent ventilation system, let's first explore the importance of having an optimized grow tent ventilation setup.

The Importance of an Optimized Grow Tent Ventilation Setup

As we briefly touched on earlier, the importance of an optimized grow tent ventilation setup cannot be overstated. The fact of the matter is you will be unable to bring a crop from seed to harvest without one. Why? There are actually a few reasons.

Grow Tent Ventilation Setup

For one, your grow lights create hot conditions within the tent. And without a means of exhausting that heat, your plants will begin to wilt. The ideal temperature for cannabis is somewhere between 68-75 degrees Fahrenheit. A well-tuned ventilation system helps you manage this.

Furthermore, plants put out a lot of humidity. Without the means of removing that humidity, the excess moisture in your confined growing tent will contribute to plant problems. One such issue is an inability to uptake nutrients through the roots - essentially starving your plants. The stomata in the foliage sense moist conditions - and shuts off the roots. But, left unchecked, excess humidity in the grow tent leads to more serious plant problems - the notorious powder mildew, or PM for short. This can kill an entire crop in just days.

But beyond just keeping your plants alive and healthy, a proper grow tent ventilation setup allows you to seal off your crop from the rest of your home. This helps keep the smells from your plants at bay, keeping your crop discreet. This is particularly important when growing in apartment buildings or states that have less-than-favorable laws surrounding home growing.

In summary, an optimized grow tent ventilation setup doesn't just help your plants thrive and reach their full potential - it's quite literally essential for bringing them from seed to harvest. And, with the right components, you can eliminate odors from compromising the location of your grow - keeping nosey neighbors from catching a whiff.

With that said, let's look at the necessary components for a proper ventilation setup for grow tent growing.

Five Essential Components for Your Ventilation Setup for Grow Tent

We've briefly touched on the four essential components for your ventilation setup for grow tent growing, but below, we'll break down each in-depth:

Exhaust Fan

This is the most important component of your ventilation setup for grow tent growing. In fact, you could potentially get by with just this one piece of equipment - although, you will likely be dissatisfied on harvest day. With that said, this is the piece of equipment responsible for expelling heat, humidity, and odors from the growing space - typically, ducted out of a window or into the attic of your home.

These need to be high-powered industrial inline duct fans so they can move a lot of air efficiently. The exhaust fan must be able to handle static pressure in the range of 0.5"-0.75" created by the filter. When shopping, you must refer to the pressure curve to pinpoint CFM delivered with a carbon filter attached. The CFM stated on the fan is not what you will get when you attach a carbon filter, which creates extra drag. More on that later.

Intake Fan

The intake fan does the opposite of what your exhaust fan does - it brings fresh air in. Without one of these, your plants wouldn't have access to the fresh air - specifically, the CO2 - they need to reach their full genetic potential. Intake fans can be much weaker than their exhaust counterpart - typically, you can get by with a booster duct fan.

Circulation Fan

While the intake and exhaust fans work in tandem to create a negative pressure balance, the circulation fan keeps air moving around your plants. You want your plants to dance, so to speak.

This not only helps strengthen stems (important for when you flip to flower, preventing broken branches). But, it also lowers the risk of plant issues like PM from leaf-on-leaf contact. These are essential in any ventilation setup for grow tent growers, but especially those operating in a SOG or SCROG layout where plants are crammed in tight quarters.

Carbon Filter

The activated carbon filter is going to be your best friend when you flip your plants to flower, and those resinous buds start stinking up a storm. You'll attach this to your exhaust fan.

When your exhaust fan pulls hot, stale, stinky air out of the tent and vents it out a window, the filter scrubs away any odors - helping you keep your crop as discreet as possible.

Thermostat Fan-Speed Controller

Now, if you're living in a particularly hot, humid climate, your ventilation setup for grow tent growing may run 24/7. This is part of why getting efficient fans you can count on is so important - it will help you keep your energy bill down. However, if you really want to know how to set up a grow tent ventilation system the right way, you'll want to pair the intake and exhaust fans with an inline fan speed controller - ideally with a thermostat built in.

With an integrated temperature and humidity sensor in the controller, your system will kick on only when needed. At the bare minimum, you'll want to ensure that your ventilation system runs on the same schedule as your grow lights - whatever that may be (18/6 during veg, 12/12 during flower).

How to Set up a Grow Tent Ventilation System: Step by Step Guide

Now you know all the necessary components for a ventilation system for grow tent growing. But, how do you go about choosing them and piecing them together to create an optimized climate for your plants?

ventilation for grow tent

This is the tricky part, as there are a few different factors at play. Fortunately, we're going to help you navigate this uncertain process so you can enjoy peace of mind and feel confident setting up your grow tent's ventilation system.

First things first - let's talk about the importance of getting quality components.

Invest in Quality Ventilation Components - You'll be Glad You Did!

Setting up your first indoor grow room or grow tent can get pricey. Depending on the size of your crop, you can expect to spend over $1,000 in the grow tent itself, ventilation components, grow lights, fertilizer, and of course, seeds/clones.

All of this is to say, we recognize how tempting it can be to try and cut corners, saving money on certain equipment. This is one of the biggest mistakes growers make. You get what you pay for in the horticulture industry. If you go with cheap fans, carbon filters, or frankly, any of your growing equipment, you'll end up paying more in the long run. Cheap equipment breaks easily and needs to be replaced prematurely. Moreover, when problems arise with these low-quality supplies, you risk losing your crop altogether - as it doesn't take long for heat and humidity to wreak havoc in your tent.

So, we encourage you to shop for the best inline fans for grow tents possible at TerraBloom. The same advice applies to the carbon filter and controller. These are investments that will deliver an ROI for years to come. The peace of mind you'll enjoy knowing your system is dialed in is well worth it - trust us. Now, let's get into the first step in how to set up a grow tent ventilation system: choosing and sizing your exhaust fan.

Step 1) Choose and Size Your Exhaust Fan & Intake Fan, Carbon Filter, & Grab a Controller

The first component you need in your grow room ventilation system is an exhaust fan. By first sizing your exhaust fan, you can easily choose an intake fan that works accordingly.

To kick things off, figure out the cubic growing space of your tent. Most grow tents are about 6' tall, but there are also short & tall variations out there. Let's say you have a 4' x 4' grow tent - that is 96 cubic feet of growing space. From there, you can calculate the cubic feet per minute - or CFM - necessary to keep your climate dialed in.

Let's say you want to exchange the air every few minutes - you would want a fan with a CFM of anywhere from 100-300 CFM. We always recommend sizing up on the CFM you need. This allows you to power the fan down and run it at a lower speed. Not only does this save you money on your energy bill, but it also creates the quietest operation possible.

Once you know what exhaust fan you need, you can choose an intake fan accordingly. Generally speaking, your intake fan should be about 20-30% less powerful than your exhaust fan. This helps create negative pressure in your grow tent where plants can thrive. There are two ways to go about this:

  • Get two fans of the exact same size and run the intake at a lower speed setting
  • Get two fans of different sizes - for example, a 6" exhaust and a 4" intake fan.

You should be sure that the size of your exhaust fan matches your carbon filter - a 6" exhaust fan pairs with a 6" carbon filter, for example. Lastly, grab a circulation fan, a fan speed controller, and some ducting to bring it all together. Then - we'll explain how to piece all of them together.

Step 2) Install Your Exhaust Fan & Carbon Filter

The first step to the actual installation of your grow tent ventilation setup is piecing together your exhaust fan and carbon filter. There are a few ways you can go about this - setting up the components inside the tent or outside, hanging or on the floor, etc. The ideal setup, however, is to hang your exhaust fan and carbon filter from a beam inside your grow tent.

Use tape or clamps to position the carbon filter & fan together, and then attach the ducting. Navigate the ducting outside your tent's duct port, and position it in a window or in the ceiling - wherever you plan on exhausting the hot, stale air from your plants.

Step 3) Install Your Intake Fan Opposite Your Exhaust Fan

With your exhaust fan installed up on the ceiling of your grow tent, you can position your intake fan on the opposite side of the tent and on the bottom. This will help create more air movement across your plants as the fresh air moves from bottom to top.

As with your exhaust fan, you'll want to use tape or clamps to attach your intake fan and ducting together. If you're bringing fresh air in from outside your home, you may want to install a HEPA filter or bug screen to prevent contaminants from entering your grow tent. Generally speaking, though, you can get by with just fresh air from the room your grow tent is situated in.

Step Four) Hang & Position Your Circulation Fans

The last moving part of your grow room ventilation system is a circulation fan. We recommend hanging two circulation fans in larger tents (over 4'x4') but smaller tents can get by with just one. Unlike your intake and exhaust fans, this circulation fan can be left on 24/7 - even when the grow lights are turned off.

Step Five) Automate the Grow Tent Ventilation Setup With Your Controller

Now comes the final step - setting up your fan speed controller and dialing in your cycle. Turn everything on and ensure it's working properly. If your fan speed controller doesn't have an integrated fan speed controller, it may be worth getting a separate hygrometer so you can see conditions in your tent at any given time.

Final Thoughts on How to Set up a Grow Tent Ventilation System

That concludes our in-depth guide on how to set up a grow tent ventilation system. As you can see, the ventilation setup for grow tent growing cannot be overlooked - besides your lighting, it's the most important piece of the indoor growing puzzle.

Fortunately, you now know everything required for a fine-tuned grow tent ventilation setup. At this point, you should feel confident in your next steps.

But if you have any questions about choosing individual components, sizing your setup, or getting things up and running, don't hesitate to reach out. TerraBloom is the #1 choice in the horticulture industry for ventilation components. You'll find our equipment in the most advanced commercial cultivation facilities around the world - and throughout home grows everywhere, too. We're here to help you make your first grow tent growing cycle a success!

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