Earth Notes: General Bibliography (green2011performance)

• [green2011performance] Robert Green and Tony Knowles The effect of Thermostatic Radiator Valves on heat pump performance (accessed 2023-03-30), UK Energy Saving Trust, 2011-06, report/number 6507 (report) (BibTeX).
  abstract

  Standard radiator systems are often used to distribute heat within properties heated by heat pumps. It is good practice, in such cases, to use Thermostatic Radiator Valves (TRVs) to control the heat output from individual radiators. However, their use will increase the tendency for the heat pump to cycle on and off. It is not clear to what extent, if at all, cycling impairs the energy performance of the heat pump. A typical fixed speed Air Source Heat Pump (ASHP) was installed in one of the Test Houses at EA Technology and a series of test undertaken to systematically vary the heat rejection capacity of the Central Heating (CH) radiator system. Results are presented for both steady-state performance and for a range of on / off cycling. Results show that provided run-times exceed a minimum value (of between 4 and 8 minutes), on/off cycling has little discernible effect on Coefficient of Performance.
  note

  [Quote: "The minimum run time can be increased by one or more of the following: Adding a buffer tank; Widening the return temperature dead-band (e.g. from, say, 5°C to 10°C); Altering the CH zoning to incorporate more radiators (and more water volume) within the reference zone." Quote: "... minimum run time is a parameter that can be readily designed for, provided information is known about heat outputs and water volume..."]