The document discusses a new type of greenhouse called Watergy, which uses internal air circulation to achieve high water recovery and crop yields. A prototype in Al Dhaid demonstrated 85% water recovery and increased CO2 levels and pesticide-free cultivation. However, challenges remain regarding costs of heat exchangers and temperature control during hot days and cold nights. Various methods are proposed to improve temperature differences for heat transfer and storage between day and night, including heat pumps, evaporative cooling, and storing heat in water or phase change materials. The document also discusses using condensed water from greenhouses for applications like desalination.

1. Dr. - Ing. Martin Buchholz, Technische Universität Berlin, Watergy GmbH Berlin
Dr.-Ing. Martin Buchholz TU-Berlin, Building Technology and Design
CEO Watergy GmbH, Berlin
New Generation Greenhouse Systems -
The Al Dhaid Prototype and Beyond

2. Dr. - Ing. Martin Buchholz, Technische Universität Berlin, Watergy GmbH Berlin

3. Dr. - Ing. Martin Buchholz, Technische Universität Berlin, Watergy GmbH Berlin
Watergy, a closed greenhouse with internal gravity driven air circulation

4. Dr. - Ing. Martin Buchholz, Technische Universität Berlin, Watergy GmbH Berlin

5. Dr. - Ing. Martin Buchholz, Technische Universität Berlin, Watergy GmbH Berlin

6. Dr. - Ing. Martin Buchholz, Technische Universität Berlin, Watergy GmbH Berlin

7. Dr. - Ing. Martin Buchholz, Technische Universität Berlin, Watergy GmbH Berlin
Big success…
+ High water recovery (85%), total water need 0,5 l/m²
+ Increased yield by CO2 accumulation (1200 ppm CO2)
+ Enclosure keeps insects out (no pesticides´)
…with remaining constraints
- High costs for heat exchanger, tower construction
- Abundancy to (cold) night time temperatures
- Limitation according to high day time temperatures
- Limitied performance of air de-humidification, results to low
evaporation rates

8. Dr. - Ing. Martin Buchholz, Technische Universität Berlin, Watergy GmbH Berlin
Exotherm Exotherm
Endotherm Endotherm

9. Dr. - Ing. Martin Buchholz, Technische Universität Berlin, Watergy GmbH Berlin

10. Dr. - Ing. Martin Buchholz, Technische Universität Berlin, Watergy GmbH Berlin

11. Dr. - Ing. Martin Buchholz, Technische Universität Berlin, Watergy GmbH Berlin

12. Dr. - Ing. Martin Buchholz, Technische Universität Berlin, Watergy GmbH Berlin

13. Dr. - Ing. Martin Buchholz, Technische Universität Berlin, Watergy GmbH Berlin

14. Dr. - Ing. Martin Buchholz, Technische Universität Berlin, Watergy GmbH Berlin
Methods for improved temperature differences between
hot/huimid air and available sources of cool
 Heat pumps ???
 Deep ocean water ???
 Evaporative cooling
 Passive cooling, Storing cooler temperatures
from night to day !!! Rejecting peak heat through night
 Evaporative cooling + air desiccation
 Cultivation of thermophile organisms, breeding
towards heat acceptance, algae
 CO2 enrichment
 Temperature difference between air layers

15. Dr. - Ing. Martin Buchholz, Technische Universität Berlin, Watergy GmbH Berlin
Methods of heat transfer between hot/humid
air and available sources of cool
 Air to air heat exchangers, use of greenhouse cover
 Increase of Surface
 Increase of heat conductivity
 Air to liquid heat exchangers
 Direct contact air to water heat exchangers
 Direct contact air to liquid desiccant heat exchangers

16. Dr. - Ing. Martin Buchholz, Technische Universität Berlin, Watergy GmbH Berlin
Methods of storing heat and cool between
day and night
 Water
 Soil
 Gravel, Sand + Water
 Substrate + Soil
 Liquid desiccants
 PCM
 Solar pond

17. Dr. - Ing. Martin Buchholz, Technische Universität Berlin, Watergy GmbH Berlin
Transport of air and storage medium
Air Ventilation:
Buoyancy driven
Wind driven (open greenhouse)
Pumping
Corrosion problem (moving parts of pumps)
Fluodyne pumps
Moving absorbers

18. Dr. - Ing. Martin Buchholz, Technische Universität Berlin, Watergy GmbH Berlin
Open Greenhouses
Fan and Pad with condenser
Fan and Pad with evaporator, external evaporator
and condenser
Fan and Pad with triple evaporator and condenser
Fan and Pad with 2 internal humidifiers and condenser
Fan and Pad with de-humidifier, humidifier and condenser
Slope greenhouse
Integration of different climatic zones

19. Dr. - Ing. Martin Buchholz, Technische Universität Berlin, Watergy GmbH Berlin
Closed Greenhouses
Fan and cooling coil
Decentralized cooler
Day/night storage integration
Additional humidifier integration
Desiccant greenhouse
Zoning of greenhouse

20. Dr. - Ing. Martin Buchholz, Technische Universität Berlin, Watergy GmbH Berlin

21. Dr. - Ing. Martin Buchholz, Technische Universität Berlin, Watergy GmbH Berlin

22. Dr. - Ing. Martin Buchholz, Technische Universität Berlin, Watergy GmbH Berlin
Water Recycling Applications

23. Dr. - Ing. Martin Buchholz, Technische Universität Berlin, Watergy GmbH Berlin
Water Recycling Applications

24. Dr. - Ing. Martin Buchholz, Technische Universität Berlin, Watergy GmbH Berlin
Condensed Water
Brackish water
Sea water
( > 90%)
Applications including desalination

25. Dr. - Ing. Martin Buchholz, Technische Universität Berlin, Watergy GmbH Berlin
Condensed water
Sea water
( > 90%)
Applications including desalination

26. Dr. - Ing. Martin Buchholz, Technische Universität Berlin, Watergy GmbH Berlin
Elimination of calcium minerals
Concentration of the brine
Na Cl
Mg Cl
Ka Cl
Applications including desalination

27. Dr. - Ing. Martin Buchholz, Technische Universität Berlin, Watergy GmbH Berlin

28. Dr. - Ing. Martin Buchholz, Technische Universität Berlin, Watergy GmbH Berlin

29. Dr. - Ing. Martin Buchholz, Technische Universität Berlin, Watergy GmbH Berlin

30. Dr. - Ing. Martin Buchholz, Technische Universität Berlin, Watergy GmbH Berlin

31. Dr. - Ing. Martin Buchholz, Technische Universität Berlin, Watergy GmbH Berlin

32. Dr. - Ing. Martin Buchholz, Technische Universität Berlin, Watergy GmbH Berlin

33. Dr. - Ing. Martin Buchholz, Technische Universität Berlin, Watergy GmbH Berlin