District heating as a modular system for new construction and renovation

For decades, district heating has been considered a reliable pillar of heat supply in densely populated areas. For a long time, however, it was strongly influenced by traditional supply structures: centralised generation, fixed temperatures, limited flexibility.

With the changing political, economic and energy conditions, a different approach is now coming to the fore. There is a demand for systems that integrate different energy sources, can be adapted to both new and existing buildings, and remain efficient and controllable. This is precisely where a system concept that views district heating not as a rigid product but as a modular construction kit comes into play. The requirements for residential buildings have shifted significantly. New buildings are designed with low flow temperatures, and existing buildings must be gradually converted from individual fossil fuel heating systems. At the same time, there is increasing pressure to obtain heat from as diverse and sustainable sources as possible. District heating remains relevant, but only if it can be further developed technically and adapted to different types of buildings.

pewo Energietechnik as a system provider for district and local heating

pewo Energietechnik has been based in Lusatia, geographically located between Dresden and Berlin, for more than three decades. The company's origins lie in individual plant engineering. This experience has led to the development of a broad portfolio that now includes both classic district heating applications and standardised solutions for local heating networks. The focus is not only on individual components, but also on the interaction of transfer stations, control and monitoring. A key issue is the decoupling of energy sources. Instead of obtaining heat exclusively from large suppliers, different sources are utilised and efficiently fed into the building via transfer points. Industrial waste heat, biomass, biogas or other renewable sources can thus be integrated into existing or new networks. This makes district heating more flexible and less dependent on individual producers.

Apartment transfer stations for new construction and renovation

In traditional residential construction, the technical approach differs significantly between new buildings and renovations. New buildings today are often designed with surface heating systems that operate at low system temperatures. In this case, apartment transfer stations offer solutions in which the temperature is regulated via underfloor heating. At the same time, a targeted temperature increase can be achieved for drinking water preparation via instantaneous water heaters in order to cover peak loads. In the renovation sector, other challenges are at the forefront. Many existing buildings are still equipped with decentralised gas floor heating systems. The switch to a centralised or decentralised district heating solution requires compact transfer stations that can be integrated into existing housing structures. The aim is to enable replacement without major structural alterations while at the same time increasing energy efficiency. Typical areas of application for transfer stations are:

• New buildings with underfloor heating and low flow temperatures
• Renovation of existing buildings with gas floor heating systems
• Decentralised supply of individual residential units
• Centralised supply of larger residential complexes
• Combination with different heat sources

Centralised and decentralised supply compared

A key difference in planning lies in the choice between centralised and decentralised heat supply. With the centralised solution, heat is generated or transferred in the basement and fed to the individual extraction points via risers. This structure is technically proven, but places higher demands on distribution and control. Decentralised supply takes a different approach. Here, each flat has its own transfer station, which is responsible for both heating and domestic hot water. District heating is supplied to the flat and used there as required. This concept enables individual control for each residential unit and at the same time reduces central distribution losses.

Booster solutions for increasing the temperature in new buildings

So-called booster solutions are becoming increasingly important in new buildings. In this case, the heat in the flow is provided at a constant temperature level throughout the year, for example via a heat pump. For drinking water preparation, this temperature is specifically raised to achieve the required tap temperature of around 60 to 70 degrees. This principle combines the efficiency of low system temperatures with the hygienic requirements of drinking water heating. Such systems are particularly suitable for buildings that are designed for high efficiency and long-term operating cost optimisation. The combination of different technologies allows the respective strengths to be exploited without unnecessarily complicating the overall system.

Control and monitoring as an integral part

In addition to hydraulics, control plays a central role. Modern district heating systems must not only provide heat, but also continuously monitor and optimise their operation. Proprietary control and monitoring solutions make it possible to analyse system operation during ongoing operation, identify efficiency potential and make targeted adjustments. This systemic approach views district heating not as a static infrastructure, but as a dynamic system. pewo Energietechnik positions itself not only as a manufacturer of individual district heating stations, but also as a provider of holistic solutions. From the basement to the apartment to the higher-level control system, this creates a consistent concept that can respond to different requirements in residential construction.

Integration into future heat supply

District and local heating are facing profound change. The variety of energy sources is increasing, while at the same time the demands for efficiency, transparency and flexibility are rising. Transfer stations, modular system solutions and intelligent control technology are becoming crucial components in this process. The approach of not only distributing heat but also actively managing it will become increasingly important in the future. Systems that cover both new construction and renovation and allow for different supply models create the basis for a long-term sustainable heating infrastructure. District heating is thus understood less as a one-way street and more as an adaptable network that responds to the real conditions in the building stock.