Dehumidification of greenhouses

Dehumidification is an essential part of greenhouse climate control. High humidity is a cause of diseases which ultimately reduce the quantity and quality of production. The humidity surrounding the crop differs since the air temperature in the greenhouse is not homogenous. Humidity control increases energy consumption during heating periods.
The various methods of dehumidification were evaluated from an economical, practical, and energetic point of view. It was concluded that the ventilation with outside air with heat recovery is the most economical, practical, and energy-saving method. Ventilation driven by buoyancy and wind cannot be controlled accurately though and gives rise to a heterogenic greenhouse climate. Therefore, the dehumidifying ventilation has to be mechanically controlled and the incoming air has to be distributed evenly over the greenhouse. Using this system the humidity can be controlled accurately in an energy-friendly way and the climate is more homogenous. For more sustainable greenhouses with lower heat demand realisable in the future this method will be indispensable.