Exclusive homes in District 22 - comfort and ecology combined

Donaustadt in Vienna, Austria

Ground-source heat pump for a new build multi-family house

"Ecological living realised by an environmentally friendly ground-source heat pump from Vaillant."

General house and system information

The facts

The energy concept


The facts

The facts

  • Housing complex with 11 residential units of a low-energy design
  • Apartment sizes from 63 to 150 m²
  • Very high-quality features including balconies and private gardens

The energy concept

The energy concept

  • Ground-source heat pump geoTHERM VWS 380/3 with output of 38 kW with an intermediate heat exchanger
  • Two multifunctional buffer cylinders allSTOR VPS, each with 1,500 litres capacity
  • Two domestic hot water stations aguaFLOW exclusiv VPM 40/45 with up to 45 l/min of continuous hot water output at 60°C
  • Two electric boilers eloBLOCK VE28
  • Room temperature controller for each residential unit including a free app
  • Permanent remote diagnosis, parameter setting and control of the heat centre with the comDIALOG online communication module



This ground-source heat pump system is installed in Austria, Donaustadt.

The starting point

An architecturally prominent development comprising eleven owner-occupied apartments was built in the Donaustadt district of Vienna. The entire concept was created with sophisticated families, couples and single people in mind. The apartments therefore include exclusive features such as patios and private gardens.

The focus of the project was a resource-conserving energy supply combined with a high level of comfort, including heating in winter and cooling in summer. As the residential units are equipped with a bath and shower and some also have multiple bathrooms, a reliable source of plentiful hot water was the top priority.

The solution

The system’s centrepiece is the geoTHERM VWS 380/3 ground-source heat pump with output of 38 kW. The heat – and passive cooling – are distributed by underfloor heating. The cooling is programmed centrally and there is a switch in every residential unit to activate it.

Hot water is generated from a central location. To meet the high hot water requirements, an allSTOR plus multifunctional buffer cylinder with capacity of 1,500 litres was incorporated into the system.

Plenty of hot water is always available and is supplied via the two aguaFLOW exclusive domestic hot water stations, each with output of up to 45 litres a minute. This output and maintenance of the water quality in accordance with the ÖNORM B 5029 standard is supported by electric post-heating with the eloBLOCK VE28. The typical demand peaks are therefore covered.

Heating comfort is controlled individually with the room thermostat app. So the occupants of each residential unit can set tailored heating scenarios and hot water temperatures and make adjustments on the fly using their smartphone.

Operating reliability thanks to service

The entire system is digitally connected and is linked to Vaillant’s customer service via the comDIALOG communication module. This means it is possible to monitor and set parameters for the system. Vaillant’s customer service is also immediately notified in the event of a malfunction, so a supply interruption within the building can usually be completely avoided.

Why choosing Vaillant is a good decision

Vaillant served as a partner from the beginning to the end of this project. From selection of the system and providing planning support through to product provision and start-up. All system components were able to be offered from a single source. This was a major advantage. The system continues to be managed by Vaillant.

Would you like free advice or more information about our heat pumps?

Find your local country website by choosing your country below.