Liquid desiccant dehumidification system for improving microclimate and plant growth in greenhouse cucumber production
High humidity is a major problem in air-tight (for energy saving) greenhouses for vegetable production because it will lead to fungal diseases and Ca deficiency on the plants. The traditional way of dehumidification through ventilation or simultaneously heating and ventilating to 'blow out' the moisture is counter-productive because it will result in significant amount of heat losses. Therefore, this project was initiated in 2011 with the aim to develop and assess the feasibility of a novel heat-driven, liquid desiccant dehumidification system for improving greenhouse microclimate for better greenhouse vegetable productivity and for reducing overall energy consumption, because the system will allow heat-recovery. A novel greenhouse dehumidification system based on heat-driven, liquid desiccant dehumidification technology was designed and installed at one of two test greenhouses at the Greenhouse and Processing Crops Research Center (Harrow, Ontario), and then a greenhouse trial on cucumbers was conducted from Sept. to Dec. 2013 to evaluate the system performance on greenhouse and plant microclimate, fruit yield and quality, in comparison to a control greenhouse with the traditional dehumidification system. The novel greenhouse dehumidification system successfully reduced greenhouse humidity and maintained a more uniform vertical temperature profile over the crop canopy. It also improved plant growth as reflected by larger leaf and higher leaf chlorophyll content, and increased fruit yield by 15% over the control greenhouse.
Hao, X., Zheng, J., Celeste, L., Guo, X. and Kholsa, S. 2017. Liquid desiccant dehumidification system for improving microclimate and plant growth in greenhouse cucumber production. Acta Hort. (ISHS) 1170:861-866
energy, yield, quality, condensation, leaf temperature