Home » Cannabis Case Study – Cannabis Greenhouses With the DryGair Solution

Cannabis Case Study – Cannabis Greenhouses With the DryGair Solution

This cannabis case study compares DryGair’s innovative dehumidifiers with traditional means of greenhouse humidity control. The case study discusess growing conditions and energy consumption, and provides an informed conclusion for cannabis growers.

Intro to Cannabis Greenhouse Case Study

The innovative DryGair solution targets one of the biggest issues in greenhouse climate control: humidity. Plant transpiration occurring within the greenhouse produces moisture in the air. If not regulated properly, humidity condenses on plant surfaces, greenhouse structures, and equipment. This creates the necessary conditions for the development of detrimental cannabis diseases including botrytis, powdery mildew, and hemp canker (white mold) which damage quality and significantly reduce yields.

The DryGair solution offers an innovative way of managing humidity that is effective, energy efficient, and economical. 

Ventilation: Not Always Possible

Traditionally, growers use ventilation for greenhouse humidity control. Openings like windows or ventilating fans lead humid air from the greenhouse out to the open air. This may lower humidity, but introducing outside air often leads to temperature loss as well, which is especially problematic at night, as the air outside is cooler. Growers must invest energy to reheat the greenhouse back to optimal levels. In cannabis production, ventilating is not always possible. Cannabis production is based on a light regime, extending day length with artificial lighting or shortening day length while using black screens. Certain regional environmental regulations require the grower to apply black screens in order to prevent issues such as light pollution. Once black screens are in use, the option for ventilating the growing facility is no longer possible, and humidity increases without any possibility to treat it. 

How Does DryGair Work?

DryGair’s concept offers an alternative to ventilation: it works in a closed greenhouse, isolated from the outside air, and reduces the humidity from within. The patented technology takes the humid indoor air, extracts humidity at a rate of 12 G/hr (45 L/hr), and circulates the dehumidified air uniformly throughout the greenhouse, minimizing moist microclimates that can lead to disease development. 

DryGair’s target operation times are during lights-off periods or activated black screen times, when a closed greenhouse benefits from dehumidification and retention of heat collected 

indoors during the day. The plants transpire and humidity rises in the greenhouse, and DryGair operates to control humidity levels in order to guarantee dry plant surfaces. During the day (lights-on period), the plants evapotranspire 10 times more than at night, leading to very high amounts of water vapor in the growing facility. At these times, the most economical option is to ventilate the greenhouse. 

Cannabis Case Study – Experiments

The data presented in this cannabis case study was gathered from data sensors measuring temperature, relative humidity, and water outputs in trials conducted in medical cannabis greenhouses. 

Relative Humidity

Within these greenhouses, DryGair maintained a steady humidity level of 57% during operation hours. Compared to fluctuating high outdoor humidity levels during the operation time. The alternative, ventilation, relies on outdoor air and is subject to fluctuation, making it ineffective when outdoor humidity is high. Additionally, when blackout screens are deployed, ventilation isn’t possible, meaning there are no measures available for humidity control. The grower gets less than optimal conditions which can lead to humidity disease outbreaks indoors.

1. DryGair was operated within a cannabis greenhouse during nighttime hours and relative humidity levels were recorded by 2 sensors located at different distances from the unit and at different heights in the greenhouse. 

2. Nighttime relative humidity levels were measured in a greenhouse using DryGair and a control greenhouse utilizing a ventilation system.

In the DryGair greenhouse, the unit maintained relative humidity levels under 70% during operating hours. Whereas the greenhouse utilizing the traditional ventilation and heating technique had relative humidity levels around 93%. 


Temperature was measured outdoors and within a closed greenhouse using DryGair (without additional heating). 

During the nighttime, outdoor temperatures dropped to 13ºC. In contrast, temperatures within the greenhouse remained ~26.5ºC consistently during DryGair’s operation. This is due to DryGair’s conversion of electric energy to heat energy and the isolation of the greenhouse from outside conditions. The DryGair concept reuses all of the energy invested in the unit’s operation. This energy can increase the temperature inside the condensed in the process. This energy can increase the temperature inside the greenhouse by 1-8ºC, depending on the greenhouse structure and needs.

Humidity Extraction

Water output volumes extracted by a DryGair unit were measured during nighttime operating hours. 

During operation, DryGair extracted a total of 740 L of water from the greenhouse air. This is a dehumidification rate of ~54 L/hr.

DryGair has the highest dehumidification rate on the market, with the capacity to extract 12 G/hr (45 L/hr)* of water.

Homogeneous Climate Conditions

Temperature and humidity sensors were placed at different heights and different distances from the DryGair unit within the greenhouse. 

Despite the different placements, uniform levels of temperature (~27ºC) and humidity (~57% RH) were found within the greenhouse. 

Uniform growing conditions produce a uniform crop, critical for the high standards required by the medical cannabis industry. DryGair is able to provide uniformity of indoor temperature, leaf temperature, and relative humidity helping to produce high quality, uniform growth of the cannabis plants. 

Additionally, the uniform conditions DryGair produces prevent microclimates in which condensation forms on plant surfaces, leading to disease outbreaks. Cannabis flowers have a dense structure which makes them especially prone to surface moisture. Mold on the flower makes it unmarketable and can have a heavy economic price for the grower. So maintaining optimal, uniform conditions is critical. 

DryGair’s Advantages in Cannabis Greenhouses

Effective Dehumidification 

DryGair is designed to extract 12 gallons of water/hr (45 L/hr)*. This is the highest output available on the market! 

Prevents Diseases

Humidity diseases such as botrytis, powdery mildew, and hemp canker lead to losses in yield and quantity. Prevention is key in managing cannabis diseases. By creating conditions that prevent diesease development, DryGair offers a solution to the problem before it can develop.

Fewer Pesticides 

Less diseases means less pesticides needed to protect cannabis crops. Reducing pesticide use is critical in complying with health and safety standards. It also saves on resources, and contributes to a greener environment. 

Energy Savings & CO2 Emission Reduction

Cannabis has one the highest environmental footprints. This is due to the high energy consumption needed to maintain the necessary growing conditions for this highly sensitive crop.

Many growers use heating or HVAC systems for climate control, which make energy a massive portion of the total growing costs.

Governments often subsidize energy-saving technologies in order to promote a greener environment and reduce CO2 emissions. DryGair allows the grower to save energy and enjoy a significant financial advantage. 

Easy Integration

DryGair’s integration is simple and easy to use. The unit is an automated plug and play solution that reduces the need for complicated infrastructure. The unit does not require any adaptation in the existing greenhouse, only minor rearranging of a few plants to make space.

Higher Quality and Quantity of Yield

DryGair’s humidity reduction capacity means less diseases in the growing facility, immediately translating to higher quality and quantity of yield. The uniformity created by DryGair leads to a more uniform product, which is especially important in cannabis production. Growers reported an increase of 30.40% in yields in greenhouses utilizing the DryGair solution. 

Fast ROI

Increased yields (30-40%) translate into greater profits for the grower. The reduction in heating

expenses (average savings of 50%) and humidity diseases lead to a return on investment of 1-3 years. This measurement is conservative and does not include additional advantages such as decrease in pesticide use, CO2 loss, decrease in working hours, etc.

Cannabis Case Study – Conclusion 

In this cannabis case study, DryGair was able to maintain the desired humidity level in the greenhouses, while creating homogenous climate conditions in all areas. DryGair’s proven results make it an important growing tool, having many advantages compared to alternative methods. This is due to the high amount of water it removes from the air, the air circulation it creates in the growing space, and the efficiency of its operation. It integrates and operates easily in the growing facility, and provides a preventative solution for humidity diseases that’s effective, economical, and sustainable. DryGair allows the grower to be competitive by preventing yield loss, maintaining high quality produce, and reducing costs. 

*at designed conditions of 65.F (18.C), 80% Relative Humidity. 

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