What does a well-functioning heating system look like? Investigation of ten Danish buildings that utilize district heating efficiently. (15th July 2021)

• Record Type: Journal Article
• Authors: Østergaard, Dorte Skaarup; Tunzi, Michele; Svendsen, Svend
• Is Part Of: Energy. Volume 227(2021)
• Publication Date: 2021-07-15
• Subjects: Low-temperature district heating -- 4th generation district heating -- District heating substations -- Low return temperatures -- Space heating -- Domestic hot water; Power resources -- Periodicals; Power (Mechanics) -- Periodicals; Energy consumption -- Periodicals; 333.7905
• DOI: 10.1016/j.energy.2021.120250
• Languages: English
• ISSNs: 0360-5442

Abstract

Abstract: In order to reach targeted 4th generation district heating temperatures around 55 °C supply and 25 °C return, it is necessary to ensure that heating installations inside buildings are designed and operated properly. In this study we investigated the best-case of current design and operation of building installations with the aim of identifying whether there is a gap between current best-case examples and future temperature targets. The study included 7 single-family dwellings and 3 apartment buildings, that were selected based on their low district heating return temperature. Data from the building substations showed that single-family dwellings obtained return temperatures in the range from 25 to 30 °C while the apartment buildings had return temperatures in the range of 30–40 °C. This indicates that there is a gap between the best functioning heating installations in apartment buildings today, and the targeted district heating return temperatures of 25–30 °C in future 4th generation district heating networks. District heating return temperatures in the range of 30–40 °C could however be the initial ambition for the existing buildings all around Europe that are expected to be connected to new district heating systems in the near future. Highlights: Single-family dwellings can obtain return temperatures in the range 25-30 °C. In these, short service pipes and no circulation of DHW were typical. Well-functioning apartment buildings had return temperatures in the range 30-40 °C. Radiator systems were equipped with balancing valves, pre-settings, and thermostats. There is a gap between current standards and future 4GDH requirements.