Ennepetal

In Ennepetal, North Rhine-Westphalia in western Germany, a private investor is building three apartment buildings of which one is being used as a reference project for achieving energy efficiency in the most economical way.

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Lessons learned What to look out for

  • The target is to reach the ‘KfW Efficiency House 55 standard’
  • Is the project economically viable and will the investment pay off?

Key facts

BuildingHeat Pump and Source
LocationEnnepetal, GermanyNumber of HP1
Constructionongoing at time of case study intakeInstalled power46 kW
Heat distributionunderfloor heating & panelOperation modemonoenergetic
Heated area– m²Heat sourceground
No. of apartments12FunctionSpace Heating
level of insulationvery good
Heating sytemDomestic Hot Water
DHW systemElectric wall heater
Heat demand– kWh / (m²a)DHW demand– kWh / (m²a)
Heating
temperature
40 °CType of systemcentral
Max. temperature65 °C
Circulation system
Other information
Cost (without drilling)70,000€COP4.4
RefrigerantR410A

Description of the technical concept

In order to reach the target – the ‘KfW Efficiency House 55 standard – ten possible system configurations were compared.

In this particular case, the planners chose the option based on a geotherm brine/water heat pump with an output of 46 kW. An eloBLOCK electric water wall heater secures peak loads and drinking water hygiene. A multi-functional storage tank with a capacity of 2,000 liters serves as a heat buffer to ensure sufficient hot water supply. Space heating is distributed via a panel heating system with a flow/return temperature of 35/30°C. All living spaces are also ventilated in a controlled manner.

This approach massively saves operating costs. A further benefit is that everything comes from a single source. Thus, the various system components are perfectly matched to each other – from the heat pump to the supporting electric heating to the identical control system.

DE006 Ennepetal 

  1. Pictures: https://www.ehpa.org/wp-content/uploads/2023/05/Heat-pumps-in-high-rise-homes_case-studies-from-across-Europe_EHPA_May-2023.pdf (Vaillant) ↩︎