Humidity control, heating and cooling in one system through a single process will be demonstrated in a greenhouse of Meyer Orchideen AG in Switzerland, closed to the Zurich airport.

Location
Meyer Ochideen AG is a very innovative enterprise: it is was founded in 1937 and today produces 500,000 orchids annually on an area of 16,000 m² in ecologically and environmentally friendly way. Through the consistent implementation of energy-saving measures in recent years as the installation of a groundwater heat pump, a large woodchip heating system and 124 kWp photovoltaic system, energy consumption has been massively reduced.

Meyer Orchideen AG recognized the technology of TheGreefa as a huge potential to reduce further the energy consumption and increase the quote of renewable energy thanks to the possibility to have loss-free energy seasonal energy storages.

Demonstrator
The sorptive greenhouse air-conditioning system is used to air-condition the greenhouse no. 12 of Meyer Orchideen AG in Wangen near to Dübendorf. The orchids in this greenhouse are in the flowering stage, which requires a constant indoor climate with a temperature of 18°C to 22°C and a relative humidity between 50% and 70%.

The main characteristics are:
• surface of the greenhouse: 600 m² ;
• 9 air conditioning units (absorbers), with 8 kW each as heat/cooling capacity, each for approx. 50 m² planting table area;
• air intake at ceiling height, evenly distributed over the planting tables;
• integration into the heating circuit and the well water system of the temperature control of the ThermoChemical Fluid (TCF) at the absorber;
• enclosure of the planting tables, air distribution under the tables;
• desorber installed outside serving all the 9 systems, including concentrated and diluted TCF-tanks;
• integration of the absorber to an evaporating cooling system located directly on the planting tables
• connection to the renewable system of the greenhouse (wood boiler, ground-water heat pump, photovoltaic panels and well water);
• shading screens automatically opened and closed to protect the crops from solar radiation and to reduce thermal losses via the roof during the night;
• buffer storages for concentrated and diluted TCF;
• TCF used: MgCl₂ .

The demonstrator will be operated in full-automatic mode for a test period of at least one year. The TCF will be regenerated in the desorber by connecting it to CO₂ -neutral heating system of the greenhouse (wood boiler, ground-water heat-pump and photovoltaic panels).

The properties of TCF stored in plastic tanks located outside the greenhouse will be analysed periodically, to ensure that there is no degradation and to demonstrate that the TCF can be used for energy loss-free seasonal storage medium.