Among the many (many) regulations cultivators are faced with, odor control is often overlooked until well into the construction process. However, because odor control regulations in many municipalities are extremely aggressive, and in most municipalities, odor control complaints can result in large fines and even license revocation, cultivators would do well to emphasize odor control during construction planning.
And It’s Not Just the Odors
Odor control in cannabis facilities has historically been considered a nuisance issue although not to everyone—some of us really love that smell! But recently we are learning that it’s not just the odor that’s the issue. The terpenes that produce that dank smell are volatile organic compounds (VOC’s), and when released into the atmosphere they can react negatively with other gases in the air and produce excessive ozone (and possibly other issues). Refer to this article for more information about what we’re learning, and about the City of Denver’s research efforts (Westword article).
5 Best Practices for Odor Control
With all of that in mind, we thought it would be prudent to talk about best practices for odor mitigation, and how you can protect your business while protecting the air we breathe (and doing a solid for your neighbors who don’t have the fondness that the rest of us share for that skunky, piney, diesely, citrusy aroma).
Pro tip: Consider odor control at the earliest phases of facility design planning, even before permitting. Effective odor control is a lot more than a bunch of carbon filters in a grow room.
1. Odor control considerations start at floor plan development, in very early stage design planning. Designing workflow and traffic patterns in your facility to optimize odor control means isolating cannabis specific areas from office and common areas. Ensure that commonly used doors (where the bulk of traffic is coming in and out of the building) is as far away from cannabis specific areas as possible.
2. The more tightly insulated your building is, the better. The better of a job you can do eliminating cracks, crevices and leak points, the less opportunity odor has to sneak out. This also allows for better biosecurity, giving bugs, fungus and pathogens fewer opportunities to enter the facility.
3. This is a big one, and probably the single most important odor control move you can make. Ensure your mechanical (HVAC) plan specifically addresses odor control, and ensure your mechanical engineer has the experience to design for an effective odor control strategy.
- Pressurization strategies must consider odor control.
For instance, if you choose to positively pressurize cultivation spaces with no equalization in adjacent spaces, you have no control over where that air goes (cracks, crevices, open doors).
- Exhaust air must consider odor control.
Limit room exhaust to only what is absolutely necessary and ensure that exhaust air is effectively filtered (at the maximum expected CFM). This will also conserve CO2, and minimize contamination from outside air entering the building, as every CFM of air that leaves must be replaced. Recirculating odor control is helpful, but those terpenes are constantly renewed. Managing what’s leaving your facility is far more important than minimizing the odor of what’s in your facility. Exhaust air can be treated with carbon, ozone, chemical deodorizers, or natural alternatives. But we find that carbon is extremely effective when properly sized, and other options only become necessary when massive amounts of exhaust are in use (as with certain greenhouse applications).
4. Drying and especially trim rooms are usually bigger sources of odor pollution than cultivation spaces. Don’t forget about them! Trim rooms also typically have high ventilation requirements due to dense occupancy during a harvest, so you have a double whammy of high terpene/odor density combined with a lot of air leaving the room.
5. Recirculating odor control strategies are most effective when utilized at high density near critical entrances or transition points. For instance, near entry doors, near the entrances to cultivation and processing areas, and in hallways serving those areas.
Effective odor control is much easier if it’s considered at the beginning of the build, and far more difficult if you’re trying to plug fingers in a leaking dam after your facility is already built. Take these strategies into account and you’ll have a leg up. Hopefully, it all makes scents now!
Need an Odor Control Plan? Contact Us.