Innovative heat supply in Schmölln: Cold local heating network with Dimplex heat pumps
Sustainable. Efficient. Forward-looking.
One of Germany's most modern heating concepts is being developed in the Robert Koch district of Schmölln: a cold local heating network supplies around 100 households with climate-friendly heat through the intelligent use of waste heat from the municipal sewage treatment plant and a nearby industrial plant.
Project facts
- Location: Schmölln, Thuringia
- Completion: 2025
- Buildings supplied: 12 large residential buildings belonging to VR-Bank Altenburger Land e.G.
- Technology: 21 highly efficientbrine/water heat pumps
- Network length: approx. 1.7 km
- This multi-million euro project is being funded by the Free State of Thuringia due to its innovative nature and because it is the first project to be combined with a sewage treatment plant.
Initial situation and requirements
The goal for Schmölln's municipal utility company was clear: they wanted to build one of the most modern and environmentally friendly heating systems, which would be funded as a pilot project by the Thuringian Ministry of the Environment.
The innovative approach to this project is that waste heat from a nearby sewage treatment plant is available for heating the 12 cooperative residential buildings with around 100 residential units in the Robert Koch district of Schmölln. By switching heat generation to waste heat and heat pumps, natural gas is being replaced as an energy source.
A 1.7 km long cold local heating network has been built, utilising waste heat from a sewage treatment plant and additional industrial waste heat from a nearby company.
The next step is to connect the nearby secondary school and municipal kindergarten to the network.
The solution
Installation and mode of operation
Sustainable solution with Dimplex heat pumps
The heat pumps installed – including models such as SIH 20 TE, SI 26 TU and SI 75 TU – ensure reliable and energy-efficient heating and hot water supply. The combination of renewable energy sources and state-of-the-art heat pump technology completely replaces the previous natural gas supply.
An energy centre including buffer storage was built near the sewage treatment plant. The cooperative residential buildings are connected to the approx. 1.7 km long cold local heating network.
The sewage treatment plant provides a flow temperature of 10 °C / 6 °C.
21 brine/water heat pumps installed for heating and hot water supply in the 12 apartment buildings
- 3x with an SIH 20TE
- 3x combination SIH 20TE + SI 75TU
- 6x combination SIH 20TE + SI 26TU
- Hot water is provided by one of the SIH 20TE units, which also supports the heating system; the second brine heat pump is used to cover the heating load.
Technical advantages at a glance
- Max. flow temperature: up to 70 °C
- COP values: up to 5.4 at B0/W35
- Energy efficiency class: A+++
- Intelligent control: via WPM Touch Master with remote access and building management system connection
Future-oriented concept
The project serves as a pilot project for climate-friendly neighbourhood solutions. In the future, the neighbouring secondary school and kindergarten will also be connected to the system. Implementation is being carried out by the specialist company Plecher & Herden in close cooperation with Schmölln municipal utilities and the Dimplex field service team.