The aroma is one of the essential features of cannabis that makes us love one strain more than the other. Whether it is fruity, sweet, skunky, or citrus, the aroma can tell you whether the weed is fresh and whether a new strain is something you already know. However, not everyone is happy to smell the cannabis odor, especially when it comes to people who are not involved in the growing process. And here come all kinds of air filters that can help you with the problem.
The aroma of cannabis comes from terpenes, special compounds that are also responsible for the psychotropic effect as they interact with major cannabinoids and can stimulate them to be more active. Every strain has its own terpene profile; some barely smell at all, while others have a very strong odor that sticks even to the clothes you have on.
In most cases, it is forbidden to let unfiltered air escape the indoor grow room or greenhouse, especially in the city area. This problem creates challenges for growers. On the one hand, it is impossible to let your garden stay without ventilation: in hot, humid air, the risk of getting mold, pests or root rot is significantly higher than in the space that has access to fresh air. Not to mention that it can be simply uncomfortable for a human to stay in such a room.
On the other hand, the choice of different kinds of filters and applications for odor control is wide, and it can become a real headache when you need to make a decision, especially when it comes to commercial growing: you do not want to make a mistake and buy several filter systems and then find the perfect option.
Home growers usually also try to hide the marijuana odor from neighbors and keep their gardens discreet.
So, if you are one of the growers who are looking for a perfect way to filter air in your garden, here is something you should know.
Carbon filters are probably the most common and popular among cannabis growers. They are relatively cheap, simple to install, reliable, and quite effective. However, they are not perfect as they require to be replaced every 2-4 months, which means that you need to have at least two sets of filters for a single crop. It can be okay if you have a little garden, but it turns into a real headache when it comes to commercial growing: replacing dozens of filters every couple of months can be not only costly but also burdensome.
Carbon filters require fans, and if you are using them for home growing, fans and filters should have appropriate sizes. Usually, you can find an instruction with the filter, and in some cases, you can even make a carbon filter of the necessary size by yourself (there are plenty of DIY videos on YouTube).
Air purifiers, or standard air filters made of woven fiber screens, are usually cheaper than carbon filters. They are quite effective for catching large particles like dust, mold, or fume, but at the same time, they are not so good for odor control.
As an option, you can choose HEPA (high-efficiency particulate arrestance) filters, but the price for such a filter would be significantly higher.
These products do not eradicate odor but mostly cover the smell, working pretty much like air fresheners in cars. They can be very simple and cheap, but the efficiency is not the best for solving the cannabis odor problem.
Instead, you can go for oils and gels that are supposed to absorb the terpenes in the air. They are not recommended to use inside your growing room as they can spoil the natural smell of your cannabis. However, if you apply them in the areas outside the room, they will do their work fine with no negative consequences.
Sealed greenhouses are the future of commercial indoor growing. They allow not only to control the odor but also protect the crop from insects and illnesses. The solution of the problem comes with letting the air circulate inside the greenhouse without exhausting it outside.
Such a greenhouse is costly; however, it allows to regulate almost all the conditions, such as air circulation, the amount of CO2, temperature, humidity, and cross-pollination. Not every sealed greenhouse manages heat and humidity, but the modern ones have systems with networks of pipes, usually situated underground, that allow to cool down the air and dehumidify it while it passes through the soil.
Another advantage of modern sealed greenhouses is their energy efficiency. They have insulated structure and preserve the heat inside even during the cold winter months.
This is a new way of controlling the odor, and you probably will not be able to find biofilters in regular agricultural stores. However, the are several small companies that have already issued biofilters that are successfully used in some commercial greenhouses. Biofilters are based on special bacteria that consume the cannabis odor molecules. Bacteria usually live in an organic material, such as woodchips.
It is not clear yet whether all the bacteria used for biofilters are absolutely safe for humans and plants, but they have presented themselves positively (for instance, in Tantalus Labs greenhouses near Vancouver), so we can expect that more tests and more data will be provided further.
Ozone generators are quite common and relatively cheap, yet very dangerous for purifying the air. Ozone gas binds with the terpenes in the air, but when it accumulates in big concentrations, ozone becomes toxic to both humans and plants. It can cause lots of health problems, mostly associated with lung diseases.
It is possible to use ozone generators if there is enough ventilation in the room; however, most growers recommend avoiding this method of filtering the air.