How to Setup ventilation system for Cannabis grow tent

An indoor garden’s ventilation system is just as important as its lighting system or nutrient regimen. The ventilation system is responsible for maintaining the atmospheric conditions (temperature, humidity, and CO2 levels) within an indoor growing space.

Temperature, humidity, and CO2 levels all directly affect photosynthesis and, therefore, the way a plant grows and develops. When these variables are kept in the desired range, a plant’s ability to photosynthesize will not be compromised.

Like other key contributors to a successful indoor garden, consistency of the ventilation system is important to providing the optimal conditions for accelerated plant growth.

In a hobby indoor garden, the ventilation system may consist of little more than intake fans, exhaust fans, and recirculating fans. For more advanced garden set-ups, the ventilation system could also include air conditioners, dehumidifiers, and CO2 enrichment equipment.

Regardless of whether a gardener implements a basic or more advanced ventilation system, the basic functions of the ventilation system remain the same: to provide uniform temperature and humidity levels within the desired range and to supply the plants with CO2 for photosynthesis.

What Is Grow Room Ventilation?

A grow room ventilation is a system that ensures a continuous flow of air between the outside world and the indoor grow area. It also includes some mechanism for keeping airflow inside the grow room.

The most common grow room systems use a combination of exhaust fans and ducts or pipes to maintain airflow. And circulation fans are used to keep the air flowing within the room.

Groom room ventilation is an important concept you should learn if you intend to start with Hydroponics.

How Does a Ventilation System Affect Plants

The main focus of a grow room is to provide plants with a better growing environment than outdoors. This also means providing fresh, CO2-rich air.

A ventilation system is crucial to keep the CO2 content inside the grow room at optimal levels for the plants. As the concentration of CO2 in the atmosphere is low, a constant flow of fresh air from outside is necessary.

Plants are used to growing in the outside weather, exposed to the wind and elements. When they are deprived of these conditions, it can affect them in unexpected ways.

Why Your Grow Tent’s Ventilation Matters?

As mentioned, having a good ventilation setup matters as this is important to your plant’s survival and even the quality of your crops.

Here we list the reasons why ventilation is important in this kind of setting.

After all, this will feel like an easier task if you understand its importance to the best of your knowledge.

Helps You Control The Humidity Level In Your Grow Room

If you’ve previously worked on an indoor grow setup and had crops or plants that grew not the way you want them to, then it might have been the uncontrolled humidity in your grow room.

....This has something to do with the quality of the plants you will have.

Another reason why controlling the humidity level in your grow room is important is because poor ventilation may lead to diseases or pest that you don’t want your plants to get.

Avoids Pests And Plant Diseases

Pests and diseases are bound to happen with poor ventilation. Most common diseases that your plants could get would be mold, mildew, spider mites, fungus, etc. These are pests and diseases that thrive in humid areas.

This could be a big problem as some of those are sometimes hard to detect.

You’ll just regret not planning on your ventilation system once this happens to you!

Keeping The CO2 Level Just Right

Photosynthesis is everything when it comes to your plants’ growth.

If you leave your grow tent closed without ventilation, your plants won’t have enough carbon dioxide.

Without CO2, your plants will just wilt and eventually die.

Your ventilation setup is what will help your plants get the right amount CO2 that they need.With enough CO2, your plants or crops will grow healthy.

Photosynthesis will be compromised if your grow room won’t have enough CO2.

To Lessen Heat And Wind Stress

Heat is unavoidable in an indoor grow room setup because you’ll be using grow lights to serve as your indoor sunlight.

Whether you’ll use ordinary grow lights or the ones that are LEDs, all of those will produce heat.

If there will be no ventilation system in your grow tent, your plants will wilt and die from heat.

Constant air circulation will lessen the intensity of heat in your grow tent.

This is the same when it comes to wind stress. Your plants will become stronger if they only get enough air.

Various Factors To Consider For a Grow Room Ventilation System

How to choose a fan for a basic ventilation system?

For beginners, a simple in-line duct fan is the best option. To find the perfect fit for your grows room, find the CFM rating for the room.

CFM stands for “cubic feet per minute.’ It is a common ratio used for all fans sold in the US and shows how much air the fan can move in a minute.

Calculate the volume of your grow room in cubic feet by multiplying its length, width, and height. For a simple system, the CFM of your fan should be greater than this number.

The guiding principle here is the idea that the exhaust fan should be able to completely replace the air inside your grow room in one minute or thereabouts.

What Fan Size Should You Get?

There are different fan sizes available that you can get. Fans usually range from four to even 12 inches in diameters.

It’s best to at least get a 6-inch fan in diameters. This should be good enough to ventilate air properly in your grow tent.

If you’re only thinking of getting a 4-inch fan or you’re simply left with no other choice, then consider getting at least two of these.

Where Should The Fans Be Placed?

Here are some tips you could follow to know where to exactly place the fans in your grow tent:

In a grow tent, it’s ideal to have at least two medium-sized fans so that the air will really have a good circulation in your grow tent. You can just place one fan above your plants and another on the ground.

Again, oscillating fans are best to use in your grow tent so that the fans won’t focus on just one area or particular plants.Remember that wind stress can cause your plants to grow weak or even worse, not grow at all.

To know if you have enough fans for your grow area, have a feel of how even the breeze is in your space.

Sizing your ventilation system

To calculate the CFM you need to properly ventilate your grow space, use the following formula: (Grow Space Width X Length X Height) / 5 = Recommended CFM.

CFM performance of a fan is affected by the length and path of 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 when using a carbon filter would be: ((Grow Space Width X Length X Height) / 5) X 1.2 = Recommended CFM.

Once you have determined the necessary CFM for your space, you can decide on your ventilation setup.

If you are planning on using air conditioning or CO2 into the room to enhance plant growth, you will see the best results with the sealed room and utilizing a inline fan and carbon filter combo to scrub the air in a closed loop system.

Air Conditioning

One of the most common devices used in a modern indoor garden is an air conditioner. More specifically, a mini-split air conditioning system. These types of air conditioners are very efficient at removing excess heat and maintaining optimal temperatures and humidity conditions.

Of all the devices used to control the atmospheric conditions in an indoor garden, an air conditioner gives growers the most control. There are many makes and models of air conditioners on the market, so it can be a little overwhelming for a new indoor horticulturist.

When shopping for an air conditioner for an indoor garden, a grower needs to pay close attention to the machine’s BTU rating. British thermal unit (BTU) is defined as the amount of heat required to raise the temperature of one pound of water by one degree Fahrenheit.

Don’t let the definition of BTU confuse you. Instead, just think of BTUs as a way to quantify heating or cooling equipment. In other words, a grower can use a BTU rating to find the appropriate size air conditioner for his or her garden.

Common grow room or tent ventilation setups

5 steps to setting up your ventilation system

There are several ways you can connect the exhaust port to the inline fan to the carbon filter. How you set it up exactly will depend on how your lights are hanging and the type of grow lighting system you’re using — does it use a reflector or not?

For LED, CMH and Fluorescent users, you won’t have a reflector you’ll have to connect to. Setup couldn’t be easier for you guys.

Step 1. Attach your inline fan to one of the extra ceiling bars that your grow tent most likely came with — adjustable rope clip handles work great as you fan will hang only a few inches from the ceiling.

Step 2. Either slide the inline fan over to fit into an exhaust hole or even easier connect your inline fan to the ducting which can be run through and out an exhaust hole.

Step 3. Hang your carbon scrubber — it most likely will come with ropes for hanging.

Step 4. Attach the carbon scrubber to the inline fan so that the fan is pulling air through the scrubber — you can use ducting or simply connect them if they are the same size.

Step 5. Confirm your components are the in proper order: Outside air is passively pulled in through the bottom intake ports up into the filter (passing air through the lights), which then moves the air through the inline fan and out the exhaust holes.

Dealing with Odor In Your Grow Room

A standard carbon filter will do the job in most cases. However, some growers may find that it isn’t enough for their particular strain or garden.

In these cases, first check your carbon filter. Make sure it is still usable, as the activated carbon loses effectiveness and the filter’s performance decreases.

grow tent odor removal with ventilation

Shaking a carbon filter can expose more of the carbon particles that have not been used in some cases.

Beyond a correctly sized and fresh carbon filter, you can deal with odor by neutralizing it through the use of an Ozone Generator, or via a chemical neutralizer like Ona’s gel based products.

All of these methods can be used together or separately as needed.

Visit our full carbon filter and odor control category

Conclusion

Your grow tent’s ventilation setup should never be ignored. If it’s your first time to do this on your own, you may go through a trial and error phase, so that you can eventually get the hang of it.

The information we’ve shared with you should already help you avoid encountering problems that have something to do with your grow room’s ventilation.

Aside from what’s mentioned above, you also need to have the basic knowledge of how everything in an indoor grow room setup works, and this includes the grow lights,air humidifiers, exhaust fans, and the requirements of the plants that you are trying to grow.