How Marijuana Grow Room Air Exchange Works

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Marijuana grow room air exchange may sound intimidating to many wannabe marijuana growers. I have some great news for you! After reading through this article you will discover that you are a genius because you will have cracked the code to creating a perfect air exchange system for your indoor canopy. 

Let’s start with the basics

You are probably aware that water, air, and light are essential for the survival of all living organisms; marijuana included. Thus, when setting up your indoor grow, it is important to prioritize these three key elements.

What Is Grow Room Air Exchange?

Grow room air exchange is a system that allows the circulation of fresh and used air within the grow room. Cannabis plants respire just like any other plant. They exchange air through the leaves, stems, and roots.

During the daytime when photosynthesis is taking place, the plants go through photorespiration which requires light. At night, these plants go through dark respiration which does not require light. 

In photorespiration, the plants take in carbon dioxide and release oxygen into the atmosphere. In dark respiration, the reverse happens. 

Grow room air exchange allows warm oxygen that has been released to rise to the top and be pushed out of the room while fresh carbon dioxide is pushed to the plants to ensure continuous respiration. At night the reverse process happens.

Outdoors, this process of air exchange takes place autonomously. Indoors due to limited ventilation it is necessary to improvise an ideal air exchange system. 

Why Is Air Circulation Important for Cannabis?

Marijuana plants in an indoor environment are very susceptible to fluctuations in internal conditions. These variations may cause changes in humidity levels and predispose the colas to mold formation. If carbon dioxide is depleted in the grow room due to improper circulation the plants will begin to die as no photosynthesis will take place. 

To prevent this from happening it is important to set up an efficient air circulation system. This will help to optimize oxygen, carbon dioxide, relative humidity, and temperature in the grow room.

Let's look more at How Marijuana Grow Room Air Exchange Works.

How To DIY Grow Room Ventilation


  1. Exhaust Fan: The exhaust fan is vital component for your indoor marijuana grow room. It collects the used air in the grow room and pushes it out to allow fresh air to get into the room. Used air is usually warm and light and so it will rise to the top of the room. Consequently, it is important to position the exhaust fans at the top of the room close to the ceiling. 
  2. Intake Fan: The intake fan plays a complementary role to the exhaust fan; it drives fresh cold air into the grow room. The intake fan should be placed below the exhaust fan and close to the plants. 
  3. Acoustic Box: This is a sound limiting device to contain any noise that may be produced by the fans. 
  4. Carbon Filter: This helps to prevent the smell of marijuana from getting out of the room. It comes in handy when you do not live in a 420-friendly neighborhood. 
  5. Ventilation Ducts: 

Small fans can be screwed to the wall or attached to support beams. Larger oscillating fans will come with their support. Small rooms may need just a single fan while larger rooms require multiple fans. You can also opt for oscillating fans that push air in and out of the grow room. The fans need to blow air over and between the canopies but not directly at the plants. Direct wind may cause windburn which causes the leaves to curl in. 

Once you have all your marijuana equipment ready and set up the next thing is to maximize air circulation. The air must be circulated evenly through the grow room to prevent stagnant areas where used air accumulates. This will cause growth challenges for plants in that vicinity. The temperature and relative humidity of the air should also be even throughout the grow room. 

The fans should work simultaneously to prevent the formation of air layers: cold air beneath and hot air on top. As soon as the warm air rises it should be pushed out by the exhaust fan while the intake fan should be quick to push in the cold fresh air. 

The stomas are necessary for respiration. They are usually concentrated on the surface underneath the leaves. Dust can easily clog the stomas and hinder adequate respiration. If your canopy is exposed to dust you will need to clean the underneath of the leaves every so often to prevent clogging the stomas. 

Do I need A Fan For My Grow?

If you are planting your marijuana indoors you will definitely needs to improvise a ventilation system which often times requires the use of fans. Marijuana plants are very sensitive to fluctuations in the environmental conditions. If your ventilation system is not adequate the plants will either become moldy or wilt away and die. 

Do I Need Air Exhaust System For My Grow Room?

An air exhaust system is necessary for every indoor grow operation. This system is similar to what has been described above; a system that uses fans to improve airflow in a grow room. What’s different is than an exhaust system works by creating negative pressure in the grow room. When low pressure is created in the grow room it pulls in cold air. 

An air exhaust system comprises of an exhaust fan, a filter, and ducts to direct the flow of air in and out of the grow room. In this system, it takes 1-2 minutes for complete air exchange to occur. 

As you have now seen setting up a grow room air circulation system is quite basic. All you need is the right equipment and the tips listed above. Let us know if you have more ideas on how marijuana grow room air exchange works. We are looking forward to learning from you.

 Marijuana Grow School Online

To begin a marijuana grow school online sign up at Cannabis Training University. CTU is the leading marijuana university and gives easy to follow instruction on how to grow marijuana indoors or out. Learn all about growing weed both indoors and out, and much more details about How Marijuana Grow Room Air Exchange Works.

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