CarbonActive
Activated Carbon Filter

Fan, activated carbon filter, hose clamps or pipe clamps, if necessary. Air silencer. EC fan controller.

With high air volumes or operation of a fan at its maximum output, it may be useful to extend the air outlet to a larger hose diameter in order to reduce the noise level of the air.

• • Activated carbon filter
  • Pollen filter -> used as a pre-filter for the supply air
  • Coarse particle filter -> used as a pre-filter for the supply air or as a pre-filter before the activated carbon filter to extend its service life

An activated carbon filter works best at a relative humidity of between 40% and 70%. Within this range, the adsorption capacity of the activated carbon for gases and pollutants remains optimal, as the moisture neither blocks the pore structure nor impairs the filter performance.

• • • Effects of relative humidity:
      
      • Humidity too low (< 30%):
        
        • Can reduce the adsorption of certain polar molecules (such as hydrogen compounds).
        • However, this usually has little effect on overall efficiency.
      • Optimal humidity (40% - 70%)
        
        • Supports adsorption, especially with mixtures of polar and non-polar molecules.
        • The pore structure remains free for the absorption of pollutants.
      • High humidity (> 70%):
        
        • Water molecules begin to occupy the pores of the activated carbon, which reduces the adsorption of pollutants such as VOCs (volatile organic compounds) and gases.
        • High humidity can also lead to the formation of condensation, which further impairs the filter performance.

An activated carbon filter works best at moderate temperatures, typically between 10°C and 40°C. In this range, the adsorption capacity of the activated carbon remains stable, as extreme temperatures can impair the adsorption properties:

• • • Low temperatures (below 10°C): Adsorption may become slower as the molecules have less energy to bind to the activated carbon.
    • High temperatures (above 40°C): Adsorption efficiency decreases because molecules can be released from the activated carbon due to the higher thermal energy (desorption)

Depending on the particulate matter content of the air and the relative humidity to which a filter is exposed, an activated carbon filter can last up to 2 years. The limiting factor is not how many odour molecules can be absorbed, but how much coarse and fine particulate matter an activated carbon filter absorbs until all the pores are clogged and no more odour molecules can bind.

Pre-filter the air of coarse particles before it enters the activated carbon filter -> in this case, an inline activated carbon filter or a CarbonActive activated carbon filter box or filter unit is required.

Keep the relative humidity below 70% to minimise clogging the pores of the activated carbon filter.

At least every 2 years or when odours are noticeable in the air outlet that were previously filtered out.

• Dark coloured pre-filter (white filter floss)
• Smells of cannabis at the air outlet

An activated carbon filter cannot be cleaned by the user or during servicing. With pellet filters, it is possible to replace the activated carbon in the filter. However, this is likely to result in a relatively messy process. As the activated carbon is compacted using a special process when it is filled during manufacturing, there will be a loss of performance if you fill the activated carbon yourself.

The air flow rate of an activated carbon filter should be greater than the air flow rate of the connected fan. If the fan can transport 150 m3 / h of air, it is recommended to use at least a 200 m3 / h activated carbon filter.

For the lowest possible noise level and long service life of the ventilation system, it is advisable to choose an activated carbon filter that allows more air to pass through per hour than the fan can transport.

For the lowest possible noise level and longevity of the ventilation system, it is advisable to choose an activated carbon filter with a higher air flow rate than the air flow rate of the fan. This is because the larger the surface area of the filter, the lower the pressure loss generated by the filter, and the lower the speed required by the fan to extract the air against the resistance of the filter.

If the activated carbon filter is sized smaller than the fan, the air speed increases, which leads to higher noise levels due to the higher impact speed of the air on the filter. In addition, a smaller surface area of the filter through which the air is drawn leads to a higher pressure loss in the filter, which the fan has to compensate for with higher speeds.

For the lowest possible noise level and longevity of the ventilation system, it is advisable to choose an activated carbon filter with a higher air flow rate than the air flow rate of the fan. This is because the larger the surface area of the filter, the lower the pressure loss generated by the filter, and the lower the speed required by the fan to extract the air against the resistance of the filter.

If you dimension the activated carbon filter about 20% larger than the maximum air flow rate of the fan, you will achieve a harmonious exhaust air setup.

• Activated carbon pellet filter
• Pleated activated carbon filter
• Granular activated carbon filter

Arrange the fan in the direction of flow AFTER the filter so that the activated carbon filter can already filter away the coarse particles with its pre-filter, so that the activated carbon only traps the very small particles and thus has a significantly longer service life.

It is best to connect the activated carbon filter and exhaust fan with a piece of flexible ducting, which is connected to both the filter and the fan with a duct clamp.

Yes, but this is only possible with inline activated carbon filters.

You can buy CarbonActive activated carbon filters from our retail partners in Germany and Switzerland. In Switzerland, FourTwenty sells our fans and filters, in Germany Dirks Growshop, Drehandel, MiHa and GrowIn.

High-quality activated carbon filters are characterised by a high specific surface area (1000-1500 m²/g), precise activation processes and an optimised pore structure that enables efficient adsorption of pollutants. They use high-quality materials such as coconut shell carbon, are robustly built, minimise pressure losses and offer a longer service life.
In contrast, inferior filters have a lower adsorption capacity, an uneven pore structure and a shorter service life. High-quality filters are also often specially adapted to pollutants, certified and can be regenerated, while inferior filters are less effective, saturate more quickly and are less durable. The quality has a decisive influence on the efficiency and durability of the filter system.

Different types of activated carbon are used for cannabis activated carbon filters. Coconut shell activated carbon offers a high adsorption capacity and is ideal for removing odours and organic compounds. Coal-based activated carbon is robust and effective with larger molecules, while wood-based activated charcoal is an inexpensive but less effective option. Impregnated activated carbon is specially treated to neutralise certain pollutants such as VOCs. Coconut shell activated carbon is often preferred as it offers excellent odour neutralisation. The choice for the type of activated carbon influences filtration efficiency, airflow and durability, so it should be chosen carefully depending on the application.

There are different types of activated carbon for cannabis activated carbon filters, which differ in their performance in exhaust air filtration:

• • • Coconut shell activated carbon: This activated carbon is used in CarbonActive filters. Particularly effective at adsorbing small organic molecules and odours thanks to its fine microporous structure. Ideal for precise odour neutralisation.
    • Coal-based activated carbon: Has a versatile pore size, making it better at binding larger molecules such as certain VOCs. It is durable and more resistant to moisture.
    • Wood-based activated charcoal: Cost-effective, but with lower adsorption capacity. Suitable for applications with less demanding pollutant profiles.
    • Impregnated activated carbon: Chemically treated for specific pollutants such as sulphur compounds. Effective for specialised applications.

The choice of activated carbon influences the binding capacity, service life and filter efficiency, depending on the type of pollutant and exhaust air composition. Coconut shell activated carbon is often the best choice for cannabis filters.

An often underestimated aspect when planning and implementing a cannabis cultivation ventilation system is the cleaning of the supply air. The filtration of supply air in cannabis cultivation is essential to protect the plants from harmful particles and impurities.

Unfiltered supply air can introduce spores, pollen, dust, pollutants and pathogenic microorganisms such as bacteria and fungi into the cultivation rooms. These particles can cause diseases, promote mould or impair the quality of the harvest. Contaminated air can also increase the risk of infestation by pest insects.

Good supply air filtration removes these problematic particles and ensures a clean environment that supports healthy plant growth. This is particularly important to ensure high yields and compliance with strict quality standards.

Eine gute Zuluftfilterung entfernt diese problematischen Partikel und sorgt für eine saubere Umgebung, die das gesunde Wachstum der Pflanzen unterstützt. Dies ist besonders wichtig, um hohe Erträge und die Einhaltung strenger Qualitätsstandards zu gewährleisten.

CarbonActive offers specialised intake pollen filters and pollen socks for intake air filtration in cannabis cultivation. These filters remove up to 99,9% of pollen and fine dust particles from the incoming air, preventing unwanted pollination and contamination of the plants.

They also protect the leaf pores (stomata) from clogging, which promotes CO₂ uptake and thus plant growth. Another advantage is the protection against pests such as spider mites, which are prevented from entering the growing space. The filters are available in different diameters to suit different system sizes.

To ensure constant filter performance, it is important to replace the pre-filters regularly.

Yes, activated carbon filters can filter pollen to a certain extent, but they are not primarily designed for this purpose. Their main function is to adsorb gases, odours and chemical compounds such as volatile organic compounds (VOCs). For the filtration of pollen, dust and other particles, however, a particle filter or a special pre-filter is more efficient.

Why activated carbon filters alone are not ideal for pollen:

• • • Pore size: the pore structure of activated carbon is designed for molecules, not for larger particles such as pollen.
    • Efficiency: Without a pre-filter, pollen can clog the activated carbon and impair its adsorption performance.
    • Recommendation: To remove pollen effectively, many systems combine activated carbon filters with particle filters (e.g. HEPA or M5 filters). The particle filter removes the pollen before the air reaches the activated carbon, which improves the overall performance and service life of the filter system.

• In Switzerland and Germany, strict legal requirements apply to air filter systems in order to ensure safety, efficiency and environmental compatibility. In Germany, the requirements are regulated in DIN EN 16798-3 and VDI 6022, which define the hygiene requirements for ventilation and air conditioning systems. These include regular inspections, maintenance and the use of suitable filter classes (e.g. in accordance with ISO 16890). The Eurovent guideline 4/23 also provides recommendations for the selection of air filters based on the outdoor air quality and the specific use of the building.
• In Switzerland, the SWKI guideline VA104-01 regulates the planning and operation of ventilation systems, including hygiene and filter standards. Particular attention is paid to the avoidance of pollutants and microorganisms in the indoor air.
• In addition, the Ecodesign guidelines, which stipulate energy-efficient systems, apply throughout Europe. Operators are obliged to replace filters regularly and maintain the systems professionally in order to guarantee compliance with hygiene and environmental protection requirements. Violations can result in penalties.

The legal basis for the air flow velocity on filters in Germany and Switzerland is essential to ensure the efficiency, service life and hygiene of air filter systems.

• • • Germany:
      
      • DIN EN 16798-3 (formerly EN 13779):
        
        • Regulates requirements for ventilation and air conditioning systems, including maximum permissible flow velocities to minimise pressure losses and filter wear.
        • Recommended flow velocity: 1.5-2.5 m/s, depending on filter class and area of application.
      • VDI 6022 (hygiene requirements):
        
        • Limitation of the flow velocity to avoid the spreading of microorganisms.
        • Maximum velocity varies depending on hygiene class and filter type.
    • Switzerland:
      
      • SWKI VA104-01:
        
        • Specifications for air routing and flow velocity to ensure hygienic operation.
        • Recommended values similar to Germany (1.5-2.5 m/s).
        • Special focus on avoiding turbulence and uneven flow.