Grow room odor control is crucial for cannabis growers, and an often-overlooked aspect of indoor and greenhouse growing. Not only does odor control for cannabis make you a better neighbor, but it improves the air quality and environment for your crop.

A quality grow room odor control system, with reliable methods like carbon filtration, can trap odor molecules instead of simply masking them to remove that weed smell. Finding the right odor control system for your operation is as simple as doing your research, asking the right questions, and choosing a high-quality system. 


Types of Grow Room Odor Control

Odor control is used for removing odor molecules from a grow room. There are multiple ways to control odor, but not all are appropriate for an indoor or greenhouse environment. There are chemical scrubbers, mostly used for natural gas odor control, and bio trickling filters are more suited for hazardous air pollutants and noxious odors. Activated carbon filters adsorb odor molecules and are most effective for enclosed or partially-enclosed environments, like a cannabis grow room.



cannabis flower smell


Absorption is when two elements become one (like water and a sponge), and adsorption is when an element holds onto another. Activated carbon, the best way to adsorb odors, is steamed to make it expand and create tiny pores which hold things like odor, chemicals and VOCs. When a carbon filter is activated, it creates miles of porous space to effectively hold months of odor.


Differences between Grow Room Odor Control and Air Filtration

An air filtration system in an agricultural setting helps filter out dust, mold, and fungi particles in the air, and makes the environment safer for the plants. Both air filtration and odor control systems let air pass through them, but odor control systems also capture odor molecules inside the carbon filter pores. Both systems are essential in a consistently successful garden and work together to bring the best results. Timing, positioning, and proper filters are crucial.

All marijuana grows need ventilation and circulation to help remove harmful contaminants from the space, but some methods are better than others. With ventilation there must be airflow taking in contaminated air and expelling clean air, creating a continuous cycle of airflow. To achieve this, a circular airflow pattern with multiple units can ensure the air is cleaned multiple times as it moves through the room. Combining an air filtration system with an odor control system can help create that track for air to circulate, with the added odor filtration for maximum benefits. 


odor control system hanging in a grow room

“If you save one crop rotation from failing then you’ve paid for everything. What is overlooked  is the actual quality of the unit you’re getting, assuming all air filters are the same.”

– Dan Schroeder, CleanLeaf Air Cleaning Specialist


Odor Control systems with additional HEPA filters are 99.97% efficient down to .3 microns at removing everything in the air, including dust and other harmful contaminants. They also help to keep the rest of your operation running smoothly. An odor control system that offers added filtration will help extend the life of your other filters and prevent them from being slowed down due to blockages. 


Cannabis and Grow Room Odor Control

Other benefits of an odor control system for cannabis include the removal of powdery mildew, prevents microclimates from developing, strengthens stems with extra airflow, and improves employee wellbeing. Odor control systems will also keep you out of trouble with your neighbors, and the location(s) in which you grow. 


“Powdery mildew and mold are a big problem in cannabis and lack of air flow can prevent that from taking hold. You’re getting rid of odor but other preventing other problems.”

– Dan Schroeder, CleanLeaf Air Cleaning Specialist


While some love the smell of cannabis, it can become overwhelming inside your facility, causing headaches, dizziness, and sinus issues for workers. Many cannabis growers have learned the hard way that their neighbors are often not huge fans of the smell either. Odor control systems not only remove the smell of the plant that is constantly giving off an odor, but they also remove the smell of other agriculture materials like fertilizer and nutrients.

Many growers have found that if their crop’s odor is too strong, their neighbors will let them know, usually by way of a complaint to the city. Strong agricultural smells, like that of the cannabis plant, can be a nuisance to unwilling passerby. Cutting out any future run-ins with the city and keeping your neighbors happy is just one strong reason why to install a grow room odor control system. 



fan blowing cannabis odor

Finding the Right Grow Room Odor Control System for You

A good grow room odor control system, with multiple filters for maximum filtration will help filter potentially dangerous substances that could harm your plants. If you can save one crop rotation from failing then the system has paid for itself. Yet, indoor and greenhouse growers often overlook filtration and odor control when assembling their operation.

Even though these systems run 24/7 with multiple air changes, the upkeep of an odor control system is very minimal. The filters must be changed regularly, standard filters are changed every three months, just like the ones in your home. The carbon filters of an odor control system are changed between 6-12 months depending on the odor of the plant. 


“Ask the right questions about their technology, if they’re not going with carbon (the tried and true) then see what the unit is capable of doing.”

– Dan Schroeder, CleanLeaf Air Cleaning Specialist


 When choosing a system capable of industrial odor control make sure you are asking the right questions. Discuss with your odor control partner if it can meet your needs; how much air is it capable of moving? How many air changes are there per hour? Does it use carbon, and if not, what method does it use to remove odor from the air? These are important to understand aspects to ensure you get the right system that can improve the air quality of your facility as well as reduce odor for your grow room staff and neighbors.