DryGair’s Mission to Prevent Mold Organically While Saving Energy

It’s based on heat exchanging technology and removes water from the air by cooling it inside the unit, reheating it, and releasing it back to the environment.

cannabis cultivation, whether medical or recreational, has a problem – mold. it’s one of the biggest issues cannabis growers face, both indoors and in greenhouses. the most common molds being bud rot (also known as gray mold or botrytis) and powdery mildew.
when it comes to other crops, growers can treat their mildew infected plants using fungicides and other toxic sprays. but cannabis is different. it’s a highly regulated plant. unlike any other crop, facilities that grow cannabis need to comply with the strict gmp standards that apply to pharmaceutical production plants.
so cannabis growers around the world have to find an alternative method to deal with mold, one that is organic and gmp compliant.


how does mold develop in cannabis?
molds are fungal pathogens, and the fungi that cause them are found everywhere. it’s close to impossible to create an environment without spores. fortunately, that’s not necessary.
fungal spores need specific conditions to infect plants and develop into harmful mildew. with the most important limiting factor being humidity.
both bud rot and powdery mildew require very humid conditions, or even free water in order to develop. but even a brief period of high humidity may be enough. once they develop, they can still spread, even in lower humidity.



preventing mold by limiting humidity
preventing mold by maintaining low humidity means growers don’t really need sprays. but controlling humidity in a space packed with cannabis plants isn’t a simple task. the plants constantly transpire, adding moisture to the grow space. in a crowded grow room or greenhouse, that means there’s a massive amount of water vapor constantly being added to the air.

drygair, a technology developed at the volcani agriculture research center, provides a solution designed specifically for cannabis cultivation – their newest dehumidifier model, the dg-x.
the company has been manufacturing dehumidifiers for horticultural use for over a decade, providing an organic solution to humidity for all types of crops and growing facilities.
drygair’s dehumidifiers are engineered to extract water from the air, at a rate that matches transpiration in the most crowded growing spaces. it’s based on heat exchanging technology and removes water from the air by cooling it inside the unit, reheating it, and releasing it back to the environment.

while drygair’s dehumidifiers provide a humidity control solution for all crops, the new dg-x model is designed with cannabis in mind.
it’s a compact dehumidifier that can fit in small spaces, but still provide a powerful extraction rate of 16 liters per hour, under the conditions found in indoor cannabis facilities. with a capacity of 8,000 m3/hour, one unit can control humidity even in relatively large grow rooms.
most importantly, it’s completely compliant with gmp requirements, making it the perfect solution for cannabis cultivation.


energy efficiency and costs of humidity control
gaining full control over climate conditions isn’t simple, and is often expensive, both in initial and operational costs.
when it comes to humidity, there are two traditional control methods – ventilation and hvac. both of which are relatively expensive, especially when energy prices are high.
ventilation means releasing humid air through exhaust fans. but when releasing air, you need to reheat or cool the space, to keep the ideal temperatures for the plants. heating and cooling rely on energy of course, and require a lot of it. furthermore, if conditions outside are too humid, or too cold, it may be impossible to reduce humidity this way. meaning mold may still develop. that’s a risk cannabis growers can’t afford.

the second method is to use hvac systems to remove water from the air. hvacs are designed for heating and cooling. but like any air conditioner, they remove some water as a side-effect of their operation.
the problem is that hvacs aren’t designed to efficiently reduce humidity. in order to continuously remove water vapor, the hvac needs to run non-stop, heating and cooling alternatingly. that requires a lot of energy, as well as larger hvac systems to be able to handle the massive amounts of water cannabis plants release.
using a dedicated dehumidifier, on the other hand, requires a relatively small amount of electricity. an efficient dehumidifier, such as a dg-x, runs on less than 5 kw, extracting 3.3 liters of water per kwh.


complete cannabis humidity control
as mentioned, cannabis is highly regulated and has very strict standards, covering all productions stages. even a small amount of mold can disqualify cannabis buds, including post-harvest. so it’s important to control humidity during the entire production process, including in drying rooms, which the dg-x is fully compatible with.
to provide comprehensive protection, drygair dehumidifiers are also equipped with a unique, patented air circulation system. it blows the treated air in all directions at once, ensuring full dispersal of the dangerous pockets of moisture between the plants and in the canopy. this helps to create uniform conditions in the space, and ultimately homogenous products.

understanding that even short periods of high humidity can be devastating, the dg-x is designed to operate effectively even in lower temperatures. temperatures drops are extremely dangerous, as colder air translates directly to higher relative humidity and may cause condensation.

the ability to ensure low humidity in all conditions and during all production stages is critical. it’s the only way to ensure mold-free products and full gmp compliance. of course, as with any issue, operational costs are a leading factor in growers’ decision making. drygair’s technology was developed to answer both, providing full protection at the highest cost-effectivity.
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this article was published in ‘medical cannabis 2022’

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