Grow Room Odor Control

Cannabis growers are faced with many unique challenges, one of the most difficult to overcome is odor control. Similar to other strongly aromatic plants, cannabis develops terpenes to attract pollinators and prevent predators through odor. While many enjoy the smell, cannabis odors can create problems for growers, surrounding communities and have been found to be contributing to pollution. The new reality is that cannabis cultivation facilities must incorporate and maintain odor control measures to protect the crops, and avoid complaints, shut-downs, or even lawsuits.

While cannabis terpenes aren’t pollution, they are classified as VOCs because they evaporate easily and release molecules into the atmosphere. Cannabis terpenes are one of many VOC sources but the molecules released can play a role in the production of ozone smog if not properly controlled. In both Colorado and Washington, regulators attribute cannabis odor to air quality issues. Cannabis cultivation facilities in Denver County have increased the total VOC emission rate by up to 3.5% with terpene emissions estimated at 362 tons per year - representing more than half the emissions of the entire state.

Cannabis plant in an indoor grow room.
Cannabis plant in an indoor grow room.

As legalized cannabis cultivation and usage are introduced into communities across North America, there are state, regional, and local regulations being established to control cannabis odors through permits, property use, and nuisance rules. Most states now require odor mitigation plans to apply for a license. Commercial grow facilities are being sued and even shut down due to violations, environmental concerns, and neighbor complaints. Cultivators in multiple states including Colorado and California have been taken to court by neighbors for cannabis odor-related issues under the Racketeer Influenced and Corrupt Organizations (RICO) Act.

Proper odor control neutralizes grow room vapors and mitigates air contaminants. Choosing the most efficient odor control system depends on the demands of the grower and cultivating process. It's important to implement odor control systems that offer maximum effectiveness and efficiency. Here are 8 common ways cannabis cultivation businesses are implementing odor control:

1. Carbon Air Filtration
Commercial grow facilities depend on high-quality air filtration to help produce their best possible yields. HVAC systems are commonly used for air filtration but the truth is they're not powerful enough to filter cannabis odor molecules or contaminated air. HVAC systems are built for heating and cooling the air and aren't equipped with the proper filter media, technology, or power to control grow room odors.

The most common filter media for VOCs is activated carbon. According to, "these are hands-down the best option for controlling marijuana grow room odors." Activated carbon filtration systems are designed to collect and remove odor molecules through adsorption. By forcing air and odors through 16 carbon canisters, the CleanLeaf Odor Series ensures maximum adsorption.

The CleanLeaf Odor Series was specifically engineered for cultivators to eliminate odor from even the most potent flowers while protecting them from contaminants like mold and mildew.

2. Odor Neutralizer
Odor neutralizers eliminate cannabis odors at the molecular level by altering the chemical state of odors.

3. Deodorization
A cleaning or disinfectant agent that masks or removes malodors. However, deodorizers can affect the health, taste and smell of your plants.

4. Odor Masking Agent
An odor masking agent is an extremely short-term solution, similar to a cologne or perfume - it's used to mask cannabis odors without changing the chemical structure or eliminating the VOCs.

5. Biofiltration
Biofiltration systems use live materials such as bark and mulch to collect and biologically degrade odors and contaminants. While biofiltration is common in large operations like waste facilities, it’s not generally recommended for grow facilities as it takes up valuable growing space and needs to be carefully controlled.

6. Fogging System
Fogging systems generate fog droplets that capture and remove odor causing molecules from the airstream.

7. Misting System
Misting systems produce neutralizer droplets that surround odor vapors until they're eliminated.

8. Vapor Phase System
Vapor phase systems rely on small vapor droplets that collide with malodors and neutralize them through a series of chemical reactions.

With all fog, mists and vapors, chemicals are released into the grow room exhaust stream, introducing a foreign element that needs to be carefully managed to prevent harm to plants and people.

From odors to pollen to mold and mildew, CleanLeaf Air Filtration Systems has the solution to give your plants the air they deserve. Whether you’re growing in a greenhouse or a grow room, our experts are here to help you #GetYourAirRight

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