Choosing the right dehumidifier for effective cannabis growing humidity control

The global medical and recreational cannabis industry continues to grow and thrive with each passing year, with estimates suggesting that it will be worth €75 billion by 2026. However, for cultivators to earn their potential share of this rapidly swelling pot, they need to produce the greatest possible yield from their plants.

Cannabis growing is a delicate equation. Without the correct balance of moisture intake, light, temperature and more, the amount of product developed can be heavily compromised, restricting its value on the open market.

This makes finding an effective way to manage the humidity around your cannabis plants in your greenhouse or grow room critical to getting the most out of your products. Here, we will illustrate the importance of humidity in the cannabis-growing process, and what factors influence the effectiveness of a Calorex dehumidifier in these environments.

The need to control humidity around cannabis

Like numerous other types of plant, the humidity needs of the cannabis plant changes depending on what stage of its growth it is in. At the earliest points of its life, the plant demands a high degree of moisture from the air while its roots begin to form:

• Germination: 70%-90% RH
• Young seedlings (12-20 days): 70%-80% RH
• Vegetation: 50%-70% RH
• Early flowering (3-4 weeks): 40%-60% RH
• Late flowering (1-3 weeks): 30%-50% RH
  

As the roots grow and strengthen, you will want to restrict the amount of moisture in the air to encourage more water to be absorbed by its nutrient-rich soil. But, as noted, this is a less-than-straightforward balancing act.

Too much moisture in the air can encourage the development of unwanted diseases and stifle the nutrient absorption of the plant. Too little humidity and the plant might dry out, hurting its quality, and cause it to become too heavily reliant on moisture from the soil, potentially causing it to develop nutrient burn.

Of all the consequences to avoid, the development of mould and fungus can significantly hurt the volume of healthy buds you yield, and the quality of the ones you are able to harvest. The two most prominent of these are:

1. Bud rot
Bud rot (botrytis cinerea) is a mould that develops in the dense cores of cannabis buds, causing them to discolour and turn mushy. This kills the value of the bud, and can potentially lead to the spread of dangerous spores that infect other plants in your facility.

2. White powdery mildew
White powdery mildew is a fungal infection spurred by high-humidity environments, which badly hurts the health of cannabis plants and restricts their growth, particularly in the flowering phases.

If you would like to know more about the influence humidity has on cannabis growing, make sure you read “The Impact of Uncontrolled Humidity on Cannabis Growing”.

Factors in determining the right climate control solution

Due to the power that humidity holds over the prospects for cannabis growing, implementing an effective, dependable climate control system is vital to optimising their environment at all stages of your plants’ growth.

At the heart of this should be a carefully selected and positioned dehumidifier. Designed over decades of experience managing harsh and hostile indoor environments, these condense dehumidifiers help you meet the moisture needs of your plant on their journey to delivering the best possible yield:

• Maintain the desired temperature and humidity throughout the entire lifecycle

• Distribute temperature evenly

• Swiftly anticipate changes in the growing environment

• Remove excess air moisture and heat loads

• Ensure constant air movement

• Prevent mildew, fungus and mould
  

However, to secure these benefits it takes more than simply acquiring a dehumidifier and placing it randomly in your greenhouse or facility. There are numerous factors that need to be considered to select the ideal system to meet your climate control requirements:

The size and layout of your facility

The scale of your facilities is critical to determining how powerful your dehumidification system needs to be and where it is positioned within your storage area. The larger an area, the more air that is filling it, and consequently the more moisture that needs to be absorbed – this demands a more robust, sizeable unit than a more compact space.

If the dehumidifier is not powerful enough to support your entire cannabis growing space, this uneven coverage will allow microclimates to form and humidity levels to spike in certain locations. As noted earlier, it only takes one plant to develop bud rot for the infection to be spread via spores to the remainder of your crops.

The layout of your structure is also a key consideration. If a room is particularly long, it may require multiple dehumidifiers spaced evenly apart to create the circular airflow necessary to protect the plants from mould and fungus. Meanwhile, in tall rooms, growers may want to duct air towards the ground to achieve the circular motion this way.

This makes it crucial to engage with specialists like our team at the Dantherm Group, who will assess your setting and refer you to the most appropriate dehumidifier for your particular structure. This could be a desiccant dehumidifier or a condensation dehumidifier depending on your set up and the size of the space where the grow is taking place.

The number of plants in the area

The amount of cannabis growing in the area will also factor in the power and capacity required from your dehumidification system. The more plants that you have dispersing water into the atmosphere through their leaves, the greater volume of moisture in the air that has to be managed.

The number of plants you house in your facility, and where they are kept, will play a key role in determining what type of dehumidifier you require, how many you need, and where they should be positioned to deliver the most complete coverage.

Your cannabis growing method

Depending on what methodology you apply to cannabis growing – Screen of Green (SCROG), Sea of Green (SOG), Low Stress Training (LST) or other – will also help guide the type of dehumidifier you use, due to the varying humidity demands of each technique.

Additional methods to control humidity
Alongside implementing a capable, well-configured dehumidification system into your cannabis-growing facility, there are a number of other techniques you can apply to manage the humidity and temperature levels of your plants:

Lowering humidity

• Increase ventilation in your facility: the introduction of mobile fans can increase the total amount of airflow in the area, dropping the humidity and lessening the potential for dangerous mould or fungi to grow and spread.

• Monitor soil moisture levels: soggy soil will tend to raise the humidity of the greenhouse or grow room, so manage this with remote monitors.

• Slight defoliation of plants: trimming the overly leafy plants can decrease the humidity of the surrounding area.

Increasing humidity

• Introducing a swamp cooler: these devices lower the overall temperature of the area while increasing the humidity.

IMPORTANT: While an air-conditioner can reinforce the work done by a dehumidifier, it should not be viewed as a like-for-like substitute. An air-conditioner is built to cool the air, not remove water from it. Also, built-in air-conditioners will rarely run at night, meaning humidity can increase during these hours and allow the development of mould and mildew.

Engage us for specialist system design

The quality, consistency and value of your cannabis yield is highly dependent on how well you can control the humidity around your plants. If you don’t want to leave anything to chance, get in touch with our team about introducing the ideal Calorex dehumidifier for your project.

Our engineers, backed by decades of expertise and experience, will closely assess your installation to determine a system capable of achieving optimal humidity levels at all times. Our robust, dependable units will maintain the conditions you require to produce the healthiest and largest yield possible every harvest.

Our systems can also incorporate data collection, remote monitoring and multiple sensors, giving you better oversight of your crops day-in and day-out.

To learn more about our units and how they support effective cannabis growing, please get in touch with our team today.