Waste heat recovery from thermal water – Therme Wien

THERMA FLEX DEMO PROJECT: Use of waste heat from thermal water

This demo is part of the lead-project ThermaFLEX that has been completed successfully. Download the final report.

Project tasks and goals

  • The utilization of waste heat from different sources is an important building block for the decarbonization of heating networks.
  • The main goal is to use the energy stored in the thermal water after internal use by the Therme Wien.
  • The waste heat obtained is fed into an existing secondary district heating network in Vienna.

Expected results

  • Use of the waste heat from the thermal water as a heat source to supply an existing district heating network section.
  • Implementation of a control algorithm with the aim of efficiently integrating the new generation unit into the existing district heating network
  • Investigations of the most relevant boundary conditions for efficient operation of the heat pumps used, and the heat exchangers based on the properties of the heat source (chemical characterization of the thermal water)

>> to the ThermaFLEX lead project


Rusbeh Rezania
T: +43 14004749121
E: rusbeh.rezania@wienenergie.at

Project key facts

01.11.2020 - 31.10.2022

funding program
Umweltförderung im Inland

Project type
Demonstration project

Project budget
3.000.000 €

Project management

Wien Energie GmbH

The following model solutions are being developed in the Waste heat recovery from thermal water – Therme Wien project:


Media reports on the project

Heating and cooling

Renewable energies are also playing an increasingly important role in space heating and air conditioning. In Austria, the share of renewable energy sources in the total heating and cooling supply is currently only 34% (only 22% in the EU).

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