Earth Notes: General Bibliography (brudermueller2023cycling)

• [brudermueller2023cycling] Brudermueller, Tobias and Kreft, Markus and Fleisch, Elgar and Staake, Thorsten Large-scale monitoring of residential heat pump cycling using smart meter data (accessed 2025-06-23), Elsevier BV, 2023-11-15, Applied Energy, volume 350, ISSN 0306-2619, doi:10.1016/j.apenergy.2023.121734, article/pages 121734, copyright Creative Commons Attribution 4.0 International, also at (article) (BibTeX).
  abstract

  Heat pumps play an essential role in decarbonizing the building sector, but their electricity consumption can vary significantly across buildings. This variability is closely related to their cycling behavior (i.e., the frequency of on-off transitions), which is also an indicator for improper sizing and non-optimal settings and can affect a heat pump's lifetime. Up to now it has been unclear which cycling behaviors are typical and atypical for heat pump operation in the field and importantly, there is a lack of methods to identify heat pumps that cycle atypically. Therefore, in this study we develop a method to monitor heat pumps with energy measurements delivered by common smart electricity meters, which also cover heat pumps without network connectivity. We show how smart meter data with 15-minute resolution can be used to extract key indicators about heat pump cycling and outline how atypical behavior can be detected after controlling for outdoor temperature. Our method is robust across different building characteristics and varying times of observation, does not require contextual information, and can be implemented with existing smart meter data, making it suitable for real-world applications. Analyzing 503 heat pumps in Swiss households over a period of 21 months, we further describe behavioral differences with respect to building and heat pump characteristics and study the relationship between heat pumps' cycling behavior, energy efficiency, and appropriate sizing. Our results show that outliers in cycling behavior are more than twice as common for air-source heat pumps than for ground-source heat pumps.
  note

  [[**CS1] Quote: "Therefore, a few studies have investigated the relationship between heating cycles and energy consumption and found a strong correlation between short cycles and energy losses. The study [...] puts these losses at 5%–30%, while [...] reports 12%. The reason for the cycling losses is that during the start-up phase of HPs, the delivered heating power is reduced until a steady state is reached. This time interval depends on the characteristics of an HP. For example, in the study of [...], the HP reaches 90% of the steady-state value after 3 min, which the authors consider relatively short. The same study concludes that a minimum time of 15 min between two consecutive cycles should be ensured. The work of [...] comes to a similar conclusion with a minimum run time of 20 min per cycle." Quote: "... a 12% drop in performance is observed when a fixed speed HP is used compared to a variable speed HP." Quote: "... the installation of a buffer tank can also increase the length of a single cycle and decrease the number of cycles." Uses average outside temperature below 12°C as indicating a heating day per Swiss standards, but 20°C as HDD base temperature.]