Earth Notes: General Bibliography (terry2023heat)

• [terry2023heat] Nicola Terry and Ray Galvin How do heat demand and energy consumption change when households transition from gas boilers to heat pumps in the UK (accessed 2023-05-22), 2023, Energy and Buildings, ISSN 0378-7788, doi:10.1016/j.enbuild.2023.113183, article/pages 113183 (article) (BibTeX).
  keywords

  Heat pumps, Heating patterns, Domestic heating, National energy demand
  abstract

  Heating with air source heat pumps is an important step in the transition to Net Zero Carbon for many households. When predicting the resulting energy consumption it is frequently assumed that heating demand is unchanged from before the switch from gas heating. However, heating patterns usually change, with a net increase in heating demand to achieve the same level of thermal comfort. This paper discusses the change in pattern and uses modelling to determine the resulting increase in energy demand. It shows that the increase can be predicted with information about dwelling heat loss and thermal mass as well as weather and the pre and post switch heating pattern. The increase can be 20% or more for homes with high heat loss. It proposes that the metric for heating demand increase would be a useful measure of heat pump readiness, and that the parameters required to assess this should be provided on energy performance certificates.
  note

  [[**CS1] Mentions Heat Geek and Better Built NW. Modelling using EnergyPlus and CODE; looks at setback temperatures. Useful table of radiator oversize factors by supply/flow temperature. Quote: "Radiators are often too small to start with. ... in 11% of homes the existing radiators were inadequate to warm the dwelling to 20°C on a peak winter day, even when supplied at 85°C. For a normal winter day, all but 5% could be heated when supplied at 80°C but when supplied at 55°C nearly half would be insufficiently warm [even] for constant heating..." Quote: "... analysis demonstrates that the extra heat demand for homes that are poorly insulated is significant and suggests extra heat demand would be a useful metric to determine if a dwelling is 'heat pump ready'." Quote: "The worst cases of high heating demand increase are for the twice a day heating schedule and the coldest location, which is Aberdeen." Quote: "... since heat pumps are normally sized for constant heating, the warm-up time would be very long in very cold conditions. An intelligent heating controller with an optimum start function could make these adjustments automatically for the householder but this is not included in a typical installation ..." Quote: "The Microgeneration Certification Scheme (MCS) best practice guide discusses three patterns: intermittent, continuous or combined i.e. intermittent with a setback temperature setting for when heating is normally not needed. For intermittent heating, the maximum power output needs to include a margin for heating up. How much of a margin is not specified. The MCS Heat Pump Design manual requires no extra power for intermittent heating provided the heat pump is sized for the 99.6% design temperature (such that the external temperature will be lower for less than 0.4% of the year). A margin for intermittent heating is required if it is sized for the 99% design temperature The difference between the 99% case and the 99.6% case varies but is usually 1–
  2~nbsp;°C. For London, the 99.6% temperature is -3.
  0~nbsp;°C while the 99% temperature is -1.
  7~nbsp;°C."]