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Ecoforest prize: ecoAWARD to the best domestic installation to Greenwatt for the renovation of a castle in Hungary.

Castle retrofit by Green Watt Zrt. – Cascade of domestic water-to-water heat pumps

  • Location: Csécse, Hungary
  • Category: 3 domestic heat pumps in cascade
  • Model: 3 ecoGEO+ B4T 5-22 HTR EH
  • Power: 66 kW
  • SCOP: 4,7
  • Services: Heating, active cooling and DHW
  • Installler: Green Watt Zrt. and Geo Concept Kft

Hungarian companies Green Watt Zrt. and Geo Concept Kft. worked together on the renovation work of the Keglevich Castle, built in 1920, to provide heating, cooling and Domestic Hot Water (DHW) while respecting the historical and aesthetic features of the building. The project presented many challenges, among them the technical room had to be installed in a former cellar with a vaulted ceiling, which required the installer to create a specific 3D plan to ensure the correct placement of the heat pumps in the building.

The installation required the drilling of thirteen 100-metre deep boreholes to supply power to three heat pumps ecoGEO+ B4T 5-22 HTR EH and two 500-litre buffer tanks made of carbon steel from Ecoforest. The system achieves a seasonal performance factor (SPF) of 4.7.

High performance in a historic building

Despite the fact that the building is 100 years old, the installation is able to achieve high efficiency, which demonstrates the potential of a well-designed installation. The installation of a cascade with three units provides a high level of redundancy and ensures that the DHW, heating and cooling needs are met. In addition, the surface area of the technical room has been reduced to a minimum.


The high performance achieved in an installation under renovation, the design of the installation and the resolution of the challenges have made this castle the winning installation in the domestic heat pump category of the ecoAWARD awards in the 2023 edition.

Ecoforest ground-source heat pumps in a renovated castle in Hungary. Installation by Green Watt.
Tanks in the installer room of a renovated castle in Hungary. Geowatt with Ecoforest equipment.
Render of the technical room of a heat pump installation in Hungary. An installation by Green Watt with Ecoforest equipment.
A snapshot of Ecoforest heat pump monitoring system. Installation in Hungary by Greenwatt.

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