Energy, Vol.180, 163-174, 2019
Faults in district heating customer installations and ways to approach them: Experiences from Swedish utilities
The district heating (DH) customer installations in current DH systems contain a variety of different faults that cause the return temperatures of the systems to increase. This is a major problem, since the focus in the DH sector is to decrease the system temperatures in order to utilize more low-temperature heat. Therefore, this study has focused on how utilities are currently working to keep their temperatures low, how they involve their customers in this work, and what faults are most common today. This was done by conducting a combined interview and survey study, where Swedish DH utilities participated. The results showed that the two most important elements to obtain low return temperatures were to have physical access to and mandate of the customer installations, and to maintain a good and close customer relationship. The results also showed that many faults occur in the customers' internal heating systems, or were due to leakages somewhere in the installation. Overall, the results showed that it is indeed possible to work close to and affect the customers to obtain lower return temperatures from the customer installations. It was also clear that the most common faults were rather easy to eliminate as long as the utilities gained physical access to the entire customer installation. (C) 2019 Elsevier Ltd. All rights reserved.