How to Properly Setup Grow Tent Ventilation for Maximum Growth

Your grow tent allows you to grow many different types of plants indoors. A key concern is the atmosphere and air quality inside your grow tent. Plants will suffer with too much heat or humidity. The main way to control the optimal growing conditions is to properly setup grow tent ventilation.

We will show you how to set up your grow tent ventilation system so that your plants get the right amount of humidity, heat, and CO2.

What Is the Importance of Grow Tent Ventilation?

When you have a grow tent, the success of your plants will depend on how well the tent is ventilated. There are a few of reasons why you should ventilate your gardening tent and the important ones are:

A. Regulate Temperature

When you have lights, they emit heat and this increases the temperature inside the grow tent. With proper ventilation, you will be able to remove the excess heat that may damage your plants.

B. Humidity Control

If humidity is not controlled, then your plants may not grow as healthily as possible. Plants will produce water vapor, which also increases humidity. The ventilation system can help control the humidity as it evacuates the humid air.

C. Keeps Diseases and Pests Away

Pests and diseases affect can affect the health of your plants. With proper air circulation and possibly a carbon filter, you will not have to worry about this as much as it can evacuate some of the pests and air-borne pathogens that can damage your plants.

D. CO2 Control

CO2 is a key ingredients to plant growth. The plants that grow outside access carbon dioxide in the air naturally. However, in the grow tent, the levels of CO2 keep decreasing because of lack of fresh air and the plant consuming what is inside the tent. Proper ventilation will bring in additional carbon dioxide from the outside.

E. Helps Strengthen the Stem of Plants

The plants that grow outside have their stems strengthened by mother nature’s wind. Air that is blown by the ventilation system will act as the substitute wind and help the plants inside the tent strengthen their stems.

While the process of setting up a tent is not usually cheap. However, when you get it right, you can be able to grow any crops at any time. As you have seen, there are many benefits that you will enjoy with an indoor plant growing tent that has proper ventilation. So let’s get right into the process of setting up the ventilation inside the grow tent.

How to Size Your Ventilation System?

Airflow is important for your grow tent or space. Most pre-configured grow tents will have already done this and supplied the properly sized equipment. However, if you are making your your own, you will need to calculate the cubic feet per minute (CFM) or air flow, use the basic formula:

Howeve, there are few factors that can affect you CFM number.

1. Length of ducting: The longer the run of ducting, the more CFM, you will need to push the air through efficiently.
2. Sag of ducting: The amount of sag in our long running duct line can cause a decrease in CFM
3. Shape of ducting: There is also a slight difference between square and round ducting or even fixed versus flexed ducting.
4. Path of ducting: If have curves or inclines in your ducting, you will need more CFM.
5. Obstacles in ducting: If you are using a carbon filter, this will further reduce your fan performance. Therefore, when using a carbon filter you must add an additional 20% to the CFM recommendation to account for the loss.

So, the formula needs to be modified slightly. When using a carbon filter would be:

For our grow tent or small rooms, that forumla works pretty good. However, for larger rooms you will need to take into account the number of times per hour that you want the air to turnover.

So, once you have determined the necessary CFM for your space, we move on to the ventilation setup.

How to Ventilate Your Grow Room?

There are a number of things that go into the setup process of the grow tent ventilation and here we break them down–step by step:

Ideally, the optimal ventilation system is having fans and carbon filters operating inside the grow tent. To do this, you need to have proper ducting to connect the filter and the fans together. Essentially, when you have the fans working properly, you control the air flow and circulation. Let’s look at the items that would make the ideal system.

Setting up Fans

You should hang the fans on the crossbar inside the tent. I typically do this using rope ratchets but in a pinch, I have used zip ties if the grow tent was small enough. Rope ratchets help in adjusting the accessories without affecting the plants. There are two types of fans that can be used inside the grow tent as ventilation. These two are:

A. Oscillating Fans

Oscillating fans are cheap and quite effective. They are known to constantly blow air all around the plants and this improves air circulation inside the tent.

Depending on the size of the grow tent, you may need to have a number of them.

If you hang your fan or if it is on stand, ensure that it is not blowing directly on your plants. This will help avoid windburn or other damage to the plants. Remmber, you want a nice breeze, not tornado or tropical storm force winds blowing at them.

B. Air Extractor Fan Setup

An air extractor is used in the ventilation system to take out old air and bring in fresh air. Sometimes they are paired with a carbon filter.

I’ve found it best to hang the extractor fan on the crossbar and ensure that it runs once in every 5-10 minutes. This helps to ensure you have proper air circulation inside the tent.

Bring Air into the Grow Tent

You can be able to bring in the air into the grow tent through two ways; either passive or active intake.

A. Passive Intake

The passive intake relies on the negative pressure and passive airflow. Basically, this allows you to blow air out but there is not a fan that blows air inside.

With this setup, you will need to create a hole that will allows air to get into the tent passively. This hole should be about 3-4 times larger than the exhaust hole. This enhances the effectiveness of the fan and prevents it from being overworked. Ultimately, this provides your ventilation great suction.

B. Active Intake

As its name implies, active intake systems move air via the fans directly. Simply, there is a fan that blows air in and another one that blows air out. For this setup, the size of the intake hole does not really matter as the fan does all the work.

Humidity Control

The other bit of ventilation set up in the tent is to be able to control humidity.

Humidity is largely a result of transpiration. Transpiration is the process where water is pulled through the roots to small pores on the underside of the leaves of the plant where it changes to vapor then disipates to the surrounding atmosphere.

This is why plants stop growing when they dry out. Not only are they deprived of water, they are being starved of nutrients.

Now, the flip side, with too much humidity in the air this creates an environment that prevents evaporation. As such this limits the plant’s ability to perform transpiration. Also, the extra moisture can create an envrionment ripe for diseases and pests to develop.

So you need to be able to raise and lower the humidity in your grow room or tent easily to help maintain optimal growing conditions.

You will want to find a ventilation system that will control the humidity levels so as to prevent diseases. The process of lowering humidity levels is quite simple as you will just need to push the humid air out using the exhaust fan. The dehumidifier is also another accessory that you can choose to have inside the grow tent.

There are other instances when you may be forced to increase the humidity levels. This can be done by sealing off the grow tent and switching off the exhaust fan. However, before doing this, you should have proper research so as to determine the amount of humidity that is favorable for your plants. Larger plants will produce more water vapor and as such, they may have to keep an eye on the humidity levels more often.

Injecting CO2

The final aspect that you may need to look at is the injection of carbon dioxide (CO2).

CO2 is an essential element for transpiration to take place. Because of the confined nature of a grow tent, CO2 levels seem to be too low and this is why you may have to inject it.

Proper injection of carbon dioxide requires a properly sealed grow tent. Sealing the grow tent completely will help increase the concentration levels of carbon dioxide.

IMPORTANT, you also need to seal off the tent for safety reasons. CO2 is deadly to humans (and our pets). You do not want the CO2 to leak into your home. I also recommend a CO2 detector as a safety precaution!

Carbon Filter

A carbon filter’s primary function to remove impurities in the environment. When growing certain plants, this is important when it comes to odor management. Make sure you check out our best carbon filters review.

When you are growing indoor plants, you will use fertilizers, nutrients, and sometimes pesticides. While these do have benefits, they can also leave a foul odor.

These unpleasant smells can be strong and can reach even outside the grow tent. This is the reason why you need to invest in the best carbon filter for grow tent.

In addition to odor management, carbon filters will help eliminate compounds that often cause diseases for your plants. Basically, it removes many air-borne pathogens thus creating optimal conditions for healthy plants.

Carbon filters exist in two principal styles. The first style is only a carbon filter. The second style is a carbon filter plus fan combo. In the case of the latter, the carbon filter also functions as an inline exhaust fan. That part is important as the carbon filter needs to be on the ex-filtration side.

Additionally, you may see them as a square or rectangular file much like the air filter for your furnace. However, the most common type in indoor gardening is a cylindrical filter.

A carbon filter use active carbon or carbon that has been oxygen-treated. Inside the filter is a highly-porous charcoal that allows air to pass through. As it passes through, the carbon traps the foul smell that could escape. Leaving you with odor free air.

Final Thoughts How to Properly Setup Grow Tent Ventilation

The process to setup up grow tent ventilation may sound quite complicated. However, as long as you can understand the different aspects of ventilation as noted above, you should not have too much difficulty. More and more grow tent kits are coming with everything you need.

There are so many benefits associated with a good ventilation system in your grow tent. From my experience, one should never compromise on the quality of the accessories that you will have inside the grow tent.

I hope you found this guide useful. Please feel free to share it with others so that they can learn how to properly setup grow tent ventilation and get bigger and better plants.