Article thumbnail

Field studies of domestic hot water comfort in semi-detached houses during summertime

By Tommy Persson and Janusz Wollerstrand


The paper describes measurements performed in three district heating (DH) substations in semidetached houses. In all these houses more than 40 % of the domestic hot water (DHW) tappings turned out to be shorter than 10 s. The fraction of total energy used to heat this water varied between 2.4 % and 10.2 %, indicating a large influence of households' daily habits. For 60-78 % of tappings, the total amount of supplied DH water volume was below 2.5 litres, which underlines the importance of using small volume pulses for the energy metering. When analysing the off-load behaviour of the DH substations it was established that radiator circuit control valves for the most part of the studied period were working on/off. During periods when there was no radiator load, the primary supply temperature was typically 50-60 degrees C, which was higher than expected. The differences in supply temperature level between the substations might be caused by leaking valves or by differences in off-load set point temperature of DHW control valves. Furthermore, the measurements indicate large differences among DHW controllers regarding the characteristics of the feed-forward control. In more than 80 % of the tappings with duration of more than 10 s, an outgoing DHW temperature of at least 40 degrees C was obtained within a maximum of 10 s. However, depending on the house studied, in 17-55 % of those tappings the monitored DHW temperature did not reach the level of at least 50 degrees C, as required by the Swedish District Heating Association

Topics: Energy Engineering
Publisher: 'Norwegian University of Science and Technology (NTNU) Library'
Year: 2005
OAI identifier:
Download PDF:
Sorry, we are unable to provide the full text but you may find it at the following location(s):
  • (external link)
  • Suggested articles

    To submit an update or takedown request for this paper, please submit an Update/Correction/Removal Request.