cannabis HVAC

Dehumidification for Medical Cannabis


According to research, Cannabis grows well in South Africa’s climate, and now that the regulator has awarded cultivation licenses, large-scale local production is a step closer.

Medicinal cannabis has become a growth industry in the South African healthcare sector, with a wide range of clinical applications.

Cannabis is a very sensitive plant to grow and is particularly sensitive to high humidity. At certain stages of the cannabis plant life, different levels of humidity are needed so that seeding, growing and flowering takes place optimally.

Where does humidity come from in a closed growing facility?

growing cannabis in South Africa

Humidity and temperature are interconnected and affect one another. Humidity is created by the plant’s respiration, through soil evaporation, grow room equipment such as grow lights, temperature changes as well as the natural moisture contained in the air.

When the air becomes saturated with water vapor (i.e. it reaches dew point) liquid water/condensation begins to appear. Condensation may occur either by an increase in the amount of water vapor, or a decrease in temperature.

Dangerous levels of humidity may be detected by the appearance of water on leaves, lights or greenhouse structural elements. When this occurs, plant growth is halted as mold and disease development starts.


cannabis humidity problemsCannabis is very sensitive to high humidity – in an isolated environment such as a growing room or a greenhouse, humidity will always reach 100% regardless of the temperature due to constant evaporation from plants and the amount of water in the air that increases continuously.

Symptoms of dangerous humidity levels are often ignored and only reacted to once diseases begin to affect production. It is extremely difficult to eradicate diseases in such situations, and much simpler and cheaper to avoid their appearance entirely.


Creating and controlling the ideal balance of humidity levels through each stage of growth is vital and is possible using a Munters desiccant dehumidifier.

Health, safety and hygiene factors are important factors to consider when growing medicinal cannabis.

The Munters Plus systems with its patented rotors are continuously being tested independently and the Rotors have been proven by The Swedish Institute for Food and Biotechnology to have both bactericidal and fungicidal properties.

Munters ML Plus system SMAC Enterprises

The Munters ML and MX Plus Desiccant systems have high filtration that not only remove particles in the air but kills bacteria as the air moves through the rotor producing filtered, clean air.

Desiccant dehumidifiers are especially well-suited for removing moisture from the air at low temperatures (even at minus degrees) and at low humidity levels..

At the heart of these dehumidifiers is a patented desiccant wheel consisting of a corrugated fiberglass structure, which contains a hygroscopic material (desiccants such as silica gel or lithium-chloride). Air passes through the flutes of the material, contacting the desiccant.

The Munters Desiccant Rotor

Animation of a desiccant rotor

The incoming process air stream gives off its moisture to the desiccant. The process air is dry as it leaves the wheel.

The humidity-laden wheel rotates slowly into a second, smaller airstream which has been heated.

This smaller exhaust airstream, known as reactivation air, warms the desiccant.

The warmed desiccant gives off its moisture which is then carried away by the reactivation air. The newly dried desiccant material is rotated back into the process air, where it absorbs moisture once again.

Desiccant systems are extremely efficient and simple in that they use rejected heat from the condenser to regenerate the desiccant wheel. 

Which Munters dehumidification system is suitable for growing medicinal Cannabis?

Munters ML Plus system SMAC Enterprises


The Munters ML Plus System is ideal for growing high grade medical cannabis as it offers Humidification, Cooling and Heating, all in one unit. 



A flexible standard system:

      1. Short delivery and start-up time thanks to predefined modules
      2. Easy plug & play installation

Hygienic design:

      1. Easy to clean and meets demanding requirements on hygiene.
      2. Integrated drip pan and excellent drainage system
      3. Stainless Steel as option
      4. Clean room HEPA filters as option
      5. Bacteriostatic High Performance Silicagel (HPS) rotor (tested by the Swedish SIK Institute)
      6. High moisture absorbing capacity year after year.

Energy & money saving: 

      1. Humidification, Cooling, Heating & Dehumidification in one unit.
      2. Constant climate saves energy
      3. Smaller foot print compared to separate units
      4. Single point supplier & After Sales partner
      5. Only one CE mark

Advanced controls: 

      1. First class temperature and humidity control
      2. Energy saving thyristor control of heater
      3. Frequency converter for fans
      4. Variety of communication modules as options


Let our Munters trained specialists calculate the amount of water the dehumidifier should remove from the air taking into consideration the size of the room, the amount of water the plants evaporate, the required relative humidity level needed as well as other factors in order to recommend the best suited Munters Dehumidifier for your Cannabis grow room or dry room.

Munters are worldwide leaders in the treatment of air through desiccant dehumidification systems and are the original inventors of the Desiccant Rotor that was patented in 1947. The full Munters Dehumidifier range is ideal for agricultural growing needs producing immediate results. Contact our experienced Product Specialist who has worked with many of the Cannabis Growers in South Africa.


SMAC Enterprises is able to supply and install dehumidification units as well as provide spare parts and maintenance plans for your unit to help you establish full control over humidity conditions in important structures, equipment and processes.  

Let us assist you on how to apply advanced absorption dehumidification technology to control and manage humidity effectively in your Cannabis grow rooms and dry rooms.


SMAC Enterprises are the official representatives for Munters AirTech in South Africa and are sole distributers for Munters Dehumidifiers within the Southern Africa region.