Swiss Demonstrators in Zurich

Thermal potential use and low-temperature drying

ZHAW will prove the use of thermal potential at high temperature for the regeneration in combination with an air control system at low temperature.

Greenhouse Swissorchid: air control

The greenhouse Swissorchid is specialised in the cultivation of orchids. It is situated in Wangen nearby Zurich and occupies an area of approximately 16‘000 m2.

The enterprise is very environmental-oriented, utilised already renewable energy. The right combination of air humidity and temperature is a successful factor for the growth of the flowers.


Absorbers in the greenhouse (under construction)


Transparent lab-absorber tested in the greenhouse

Absorbers in the greenhouse (under construction)

ZHAW will test in Wangen air control systems based on the absorption process expecting a significant improvement in the energy consumption due to:

  • Reduction of the ventilation losses: ventilation is not required anymore to control the air humidity
  • No air undercooling to remove the excess humidity as in standard processes

New concept of air distribution in greenhouse

A well-designed distribution system of the conditioned air from the absorber guarantees a high level of efficiency and comfort. Furthermore, it reduces also the operation cost.
The conditioned air is necessary only around the crops and not in the entire greenhouse. ZHAW is developing together to the absorber for the demonstrator greenhouse a new air system which injects the conditioned air directly below the crops.

Schema of the conditioning system in the Swiss Demonstrator for greenhouses

This configuration allows to save energy because it is not necessary anymore to treat the air of the entire greenhouse to reach the required conditions but only the air above the crops. Another advantage is the possibility to create different climate conditions inside the same room associating an absorber for each table which required different air conditions (because of different crops).

Biogas plant Marthalen: salt regeneration

The biogas plant in Marthalen produces approximately 300 kWe in a biogas engine. In the area there is no need of heat at high temperature. A small part of the residual heat is recovered for internal consumption, the rest is released to the ambient.

Marthalen is situated in an agriculture area, where there is no need of heat at high temperature. The residual heat can be used to regenerate the salt solution of a future thermochemical network (H-DisNet). 


ZHAW will demonstrate that not only the thermal energy can be used to regenerate the salt solution, but also the thermal potential in terms of a chemical potential. Simultaneously to the regeneration process, the heat present in the flue gas is shifted to a suitable temperature for domestic demand without a reduction of energy.