Watergy: Infrastructure for Process Control in a Closed Greenhouse in Semi-arid Regions

Abstract A novel solar humid-air-collector system for combined water treatment, space-cooling and ¿heating has been designed in an EU framework-5 financed project called Watergy. The design consists of a construction of two prototypes for applications in architecture and greenhouse horticulture: a South European variant (for arid climate and emphasis on agricultural use) and a Central-/North European variant (for temperate climate and emphasis on integral building design). The core is the development of a collector system, following the principle of a closed, two phase thermo siphon. It achieves combined evaporation and ¿condensation, efficient heat transfer to a central heat exchanger as well as increased heat conduction from (humid) air to water. Main improvements are cost reduction in space heating and -cooling of buildings and greenhouses. Furthermore, viability increases by additional integration of greenhouse irrigation water recycling, desalination and building grey-water recycling. Sensors and actuators, connected to low-level controllers, activate a model-based control system to manage these processes. The paper describes the different appendages, sensor systems, network connections, databases, alarming systems, user interfaces and remote management from the Netherlands to Spain through the Internet.