Earth Notes: General Bibliography (farmer2026TRV)

• [farmer2026TRV] David Farmer and Ben Roberts and Bill George and Damon Hart-Davis and Phil Clarke BEAMA Air Source Heat Pump TRV Salford Energy House Test (accessed 2026-04-16), University of Salford, Salford, UK, 2026-01, PDF (report) (BibTeX).
  abstract

  This report presents findings from the BEAMA Energy House Air Source Heat Pump (ASHP) Thermostatic Radiator Valve (TRV) Project undertaken at the University of Salford Energy House 1 test facility. The project was designed to assess the impact of TRVs on ASHP performance and inform future modelling of TRV use with ASHP systems. Unlike gas central heating systems, TRVs are often omitted from ASHP installations based on concerns that they may reduce system efficiency and increase energy use. However, open-circuit design relies upon accurate sizing calculations and use of an appropriate weather compensation curve, neither of which can be guaranteed. Furthermore, open-circuit design limits occupant control and can lead to overheating in rooms with uncontrolled heat gains. Tests were therefore conducted to measure how trimming room temperatures using TRVs influences internal conditions, ASHP efficiency, and space heating energy consumption. The Energy House, a Victorian solid wall end-terrace dwelling within an environmental chamber was equipped with an ASHP and radiators sized for a for a 45 °C flow temperature. Its heating circuit contained a volumiser and automatic bypass valve. Tests were performed under constant and diurnal external temperature profiles based on a typical UK winter day. The temperature of rooms accounting for around half of the internal volume of the Energy House was trimmed by 2–3 °C. The impact of both traditional and smart TRVs, volumiser integration, and differing heating patterns was tested. The tests found that trimming internal temperatures with both traditional and smart TRVs reduced ASHP space heating energy consumption and did not significantly impact its coefficient of performance (COP). Reductions in energy consumption were proportional to reductions in space heating demand (internal to external temperature difference) achieved using TRVs. The trimming scenarios tested resulted in space heating energy savings of between 6-8%. The findings suggest that TRVs can be used to provide occupants with greater internal temperature control and reduce ASHP space heating energy use, as is customary with gas central heating systems. Although, those with ASHP systems wishing to limit internal temperatures should initially reduce the flow temperature and programme setbacks, with TRVs used as a secondary measure. Using TRVs requires adequate volume within a system and flow rates to be maintained. Therefore, a volumiser and automatic bypass valve should be installed alongside an ASHP.
  note

  [[**CS1] See also https://www.beama.org.uk/static/60755141-dcb6-4143-9ac9ea0264b1f874/BEAMA-Technical-Bulletin-Summary-of-BEAMA-Air-Source-Heat-Pump-TRV-Salford-Energy-House-Test.pdf Quote: "This report has established that TRVs can reduce ASHP space heating energy consumption by 6-8% without reducing appliance and system efficiency and can reduce the air temperature of adjoining zones. TRVs have the potential to provide greater internal temperature control to occupants and reduce ASHP space heating energy use. It is important for a volumiser and automatic bypass to be installed alongside the ASHP to ensure the adequate volume in the system is achieved. TRVs should be used as a secondary measure to reduce internal temperatures."]