Pilot study on liquid desiccant systems in greenhouse for water saving and climate control

Abstract

In regions with hot and arid climates, meeting the growing demands for irrigation and food production is crucial. Greenhouse farming offers a promising solution, significantly enhancing agricultural water efficiency by producing high-value crops with reduced freshwater consumption compared to traditional methods. However, the reliance on freshwater-dependent evaporative cooling systems in greenhouses poses a significant challenge, consuming up to 80 % of total freshwater usage. This challenge underscores the urgent need for innovative solutions to reduce freshwater use while maintaining optimal greenhouse conditions.This study proposes integrating a desiccant system with conventional evaporative cooling to improve humidity control and reduce freshwater consumption. This innovative approach enables greenhouse establishment in humid coastal areas previously deemed unsuitable, offering a sustainable alternative to traditional cooling methods. The proposed system includes liquid desiccant, desiccant pads, a chiller, and a fan, aiming to reduce or eliminate water use during nighttime cooling cycles. Additionally, the system has the potential to harvest water from ambient air, further reducing overall water consumption. Through this case study, we address the critical issue of freshwater overuse in greenhouse agriculture, presenting a solution that could revolutionize water management practices in arid and semi-arid regions.