Principle of a heating network

A district heating network produces and distributes centrally-produced heat. It comprises one or more heat production units, a primary distribution network through which heat is transported in the form of a heat transfer fluid to substations, from which connected buildings are served by a secondary distribution network. A district heating network is a kind of central heating system for a district or even a city, and is therefore also known as district heating. This distribution of collective heat is a public service and therefore falls within the remit of the local authority, in the same way as water or wastewater (figure 1 ).