Our US-made flexible pipes for local heating and district heating

For many, the foundational question is: how exactly does district heating function? District heating is a centralized heat supply system that delivers both space heating and hot water to buildings. Thermal energy is produced at centralized heat generation facilities, or "heat centers," utilizing various processes such as waste incineration and biomass combustion. Additionally, sources like waste heat, wastewater, and surface or groundwater can contribute thermal energy. Solar-based district heating is also on the rise, with expansive solar collector fields now supplying entire urban areas.

Thermally insulated piping systems carry the generated thermal energy from these facilities to end-users. Heated water flows through these pipes as the medium for energy transfer. These subterranean pipe networks, in conjunction with one or more heat centers (depending on demand and system capacity), establish the district heating infrastructure.

In discussing “local heating” or “local heating networks,” we typically refer to smaller systems with pipelines covering shorter distances. Conversely, when pipelines extend approximately five kilometers or more, the system is generally categorized as a district heating network.

As for the heat cycle: within each building, a heat exchanger transfers the incoming thermal energy to the internal heating system, enabling its use for heating and hot water. Internal heating pipes then distribute this energy throughout the building. After the thermal energy is fully utilized, return pipes transport the cooled water back to the heat center for reheating, thus completing the cycle.

The next logical question, considering the rapid development in recent years, is: why are an increasing number of cities and municipalities prioritizing the expansion of district heating networks? What draws consumers to this energy supply model? District heating presents numerous advantages, chief among them being its carbon-neutral energy provision. Furthermore, thermal energy is generated locally or within the region, with heating facilities typically located no more than 20 kilometers from the end-user. This localized setup, managed by regional providers, ensures a high degree of supply security for consumers.

Economical and operationally efficient, district heating is compatible with both traditional radiators and underfloor heating systems. This model also excels in spatial efficiency; the heat exchanger is compact, requiring minimal space compared to other heating solutions. Additionally, no supplementary tanks or storage systems are needed—only a network of heating pipes. Since heat is supplied on demand through underground piping, consumers benefit from seamless service without the need for fuel procurement, saving both time and effort. Low maintenance requirements further reduce financial burdens, making district heating one of the most cost-effective heating solutions available. 

As demand surges, more municipalities and cities are actively investing in the development and extension of district heating networks to meet consumer needs and secure a sustainable energy future.

For both local and district heating networks, we offer a range of flexible piping systems, as well as a leakage monitoring device. Each pipe solution is designed to meet project-specific needs, with unique advantages depending on the system type. Flexible pipes, typically made of plastic, offer easy adaptation to the trench layout.

Flexible polyethylene (PE) pipes achieve improved insulation performance. We use polyurethane (PUR) thermal insulation in our district and local heating pipes, which is highly effective. Furthermore, both types of pipe now offer comparable connection technologies.

When selecting the most appropriate pipe system, factors like connection technology and accessories are secondary. The primary focus should be on the specific product properties that best suit the project’s requirements.

For applications in the low-temperature range up to 203 °F (with fluctuations), our CALPEX PUR-KING product is the top choice. This innovative system sets the global standard for thermal conductivity, achieving an impressive lambda value of just 0.0199 watts per meter per Kelvin. Independent and accredited testing institutes have validated our claims of minimal heat losses, ensuring guaranteed energy efficiency. Additionally, the CALPEX PUR-KING is self-compensating, designed for continuous installation, and is ideal for long-term performance.

The distinction between local heating pipes and district heating pipes lies primarily in the distance between the heat center and the point of consumption. While both systems operate on the same basic principle of transferring thermal energy via a medium, the length of the pipeline plays a crucial role in determining whether the system is classified as local or district heating. Typically, district heating pipes are longer, whereas local heating pipes are used for shorter distances. This difference influences key material properties, particularly the balance between stability and flexibility.

The transport route of the heating network is another critical factor when expanding the system. The selection of the appropriate pipe system depends on how well it meets the terrain requirements and the planned distances for the network. The goal is to choose a pipe system that best accommodates the specific conditions, whether the pipes are being installed in urban environments or rural areas with varying soil types and topography.

Both local and district heating systems essentially serve the same function: the transfer of thermal energy. Therefore, the major difference between their requirements lies in the scale of the installation and the materials used. There is no one-size-fits-all solution for local heating pipes; the best choice depends on various project-specific factors, such as terrain, distance, and installation requirements. A final recommendation can only be made after a thorough evaluation of these factors.