Revisiting Home Heat Control Theories through a UK Care Home Field Trial

Abstract

Smart heating controls are being introduced in the domestic sector with the aim of reducing heating demand in buildings. However, the impact of controls on heat demand is not fully understood. This study set out to add empirical evidence to Kempton’s theory on mental models of home heat controls. With this purpose, radiator setpoint records from smart thermostatic valves in 47 flats from a care home in the South of England were evaluated over a 12-month period. Three types of households were identified: (i) low interactors who do not have interaction, or have minimal interaction, with the controls (24.5%); (ii) medium interactors who adjust their setpoint when the outdoor temperature changes and whose behavior is comparable to households that have a “feedback” mental model (49%); and (iii) high interactors who adjust the setpoint based on their own strategy, which does not necessarily follow outdoor temperature changes and reflects a lack of understanding of how the controls work (26.5%). These results highlight the contrast between expected and actual usage of home heat controls, as only half of the residents showed a behavior that is consistent with the principles of operation of the STVs.

Radiators Adjustment in Multi-Family Residential Buildings—An Analysis Based on Data from Heat Meters

“…However, is it a matter of the education of society or more a matter of perception and the needs of individual people, for which the age of technology is less important? Occupant behaviors consistent with valve theory were also observed by Galvin [50] in thermostat data from Germany collected in 2012 and Aragon et al in thermostat data from elderly residents collected in the UK in 2019/2020 [25]. A different picture is shown by Karjalainen's [22] research on how thermostats (including TRVs) were used in office buildings and homes in Finland, which was conducted about 15 years ago.…”

“…The second approach is to conduct the presented analysis in a building where smart TRV is implemented, e.g., ref. [25], and verify if the recorded use of the TRV could be found in heat meter data for the whole dwelling/building.…”

“…In regard to the TRV-occupant interactions, the literature is limited to surveys [21][22][23] or measurement research based on only a selection of households [19,24,25], which involve a lot of additional sensors inside the dwellings. The authors have found only one expectation: a monitoring campaign conducted in the UK, where 47 flats were observed using smart heating control systems, which were implemented in buildings based on funding support from a European project [25]; however, the presented results refer to a specific group of users: elderly residents in a care home. From the point of view of continuous control of the energy efficiency of the operation of heating systems, these are not suitable methods of monitoring.…”