First Generation

摘要

District heating (DH) is here to stay. Looking back on the history of DH it goes quite some years back. During the years it has developed to fulfil the demands as they came up, typically driven by the demand for reduced investment and heat costs, but also lower equipment space demands, concerns of energy efficiency and lower fire risks. The development has been categorised in four generations which each indicate major changes in the technology. The present article - and first one of a series - describes the first generation district heating and its energy source steam.