Indoor cultivation of industrial hemp suitable for medical use is one of the climate-controlled agricultural applications. In Türkiye this cultivation requires a permit under the Regulation on Hemp Cultivation and Control (Official Gazette 31.01.2026, No. 33154), which calls for a closed area with climate-control capability. Each stage — seedling, vegetative growth, flowering, drying and curing — needs its own temperature and relative humidity band.
In the seedling and cutting stage the typical condition is 20–25 °C and 65–80% relative humidity; plants without a developed root system are sensitive to drying out. Heated outdoor air is very dry in winter, so humidification may be needed at this stage. During vegetative growth the typical condition is 22–28 °C and 55–70% relative humidity; the vapour pressure deficit (VPD) is generally kept at 0.8–1.2 kPa.
During flowering, relative humidity is lowered step by step (early flowering 50–60%, late stage and night 40–50%). The main reason is grey mould (Botrytis cinerea), whose risk rises when relative humidity stays above 85–90% for long periods and surfaces get wet. At this stage dehumidification and air circulation matter more than humidification.
Post-harvest drying is typically carried out at 15–21 °C and 55–65% relative humidity over 7–14 days; curing continues at 18–22 °C and 58–62% relative humidity. Drying too fast causes uneven drying and loss of volatile compounds. The target water activity of the dry flower is 0.55–0.65.
In indoor growing facilities the humidification requirement is assessed together with the lighting heat load, the fresh-air volume and the plants' transpiration load. Dehumidification dominates when plants transpire heavily; humidification comes to the fore when dry outdoor air is brought in and the plant load is low. For hygiene, a resistive steam humidifier (Neptronic SKE4) produces steam free of minerals and aerosols.
As NKT Nem Kontrol Teknolojileri, we supply humidification and dehumidification equipment for these facilities and support device selection, and we provide technical service and spare parts. For device selection suited to your facility conditions, please contact us using the form below.
