Lämmönjakoon

Lämmönjakoon refers to the distribution of thermal energy from a centralized heat source to end users, typically within a district heating system. It covers the transport of hot water or steam through an insulated pipe network and the heat exchange at customer substations that transfers heat to a building’s heating and domestic hot-water systems.

How it works: A centralized plant, such as a combined heat and power plant, a heat-only boiler, or a source of industrial waste heat, produces hot fluid. The hot fluid is pumped through a primary distribution network to substations in buildings, where a heat exchanger transfers heat to the building’s circulating heating circuit. The cooler return water is sent back to the plant to be reheated. The system operates under controlled temperatures to meet demand while minimizing losses.

Network structure: District heating networks are typically described as primary distribution networks and secondary (building) networks. The primary network carries heat from the plant to substations; the secondary network distributes heat within a building to radiators, convectors, or underfloor heating. Substations include heat exchangers, pumps, and control equipment, and often meters for measuring energy supplied.

Performance and challenges: Efficiency depends on plant efficiency, network design, and insulation. Heat losses along the network can be reduced with better insulation and low-temperature operation. Investment and maintenance costs are significant, and balancing demand with supply requires real-time control. The environmental impact depends on the energy sources used; district heating can reduce CO2 emissions when renewable or waste heat is used.

Context: In many Nordic and European cities, lämmönjakoon supports urban energy planning, energy security, and the integration of renewable energy and waste heat streams.