Physical environmental and contextual drivers of occupants’ manual space heating override behaviour in UK residential buildings

This paper investigates the physical environmental (indoor and outdoor temperature and relative humidity, wind speed, solar radiation and rainfall) and contextual drivers (time of day) affecting occupants’ manual space heating override behaviour during the heating season based on measurements collected in ten UK dwellings. Logistic regression modelling is used to understand the probability of occupants manually overriding their scheduled heating periods. To the authors’ knowledge, these are the first stochastic models of manual heating override behaviour developed for residential buildings. The work reported in this paper suggests that occupants’ manual overrides are influenced by indoor and outdoor temperature, indoor relative humidity, and solar radiation. In addition, the effects of the physical environmental variables varied in relation to the time of day. At night, none of the physical environmental variables influenced manual overrides. In the morning, afternoon and evening, manual overrides were governed by a mix of indoor air temperature, indoor relative humidity and solar radiation. The models presented can be used in building performance simulation applications to improve the inputs for space heating behaviour in residential buildings and thus the predictions of energy use and indoor environmental conditions

A comparison between thermostat and thermostatic radiator valve setpoint temperatures in UK social housing

In the UK, in centrally heated dwellings, space heating is commonly controlled by a whole house thermostat as well as thermostatic radiator valves (TRVs) fitted on individual radiators. TRV settings define a setpoint temperature at which the radiator is switched off, in order to regulate zonal temperatures. This paper presents an analysis of the TRV setpoint temperatures which occupants’ select in living rooms and main bedrooms and provides a comparison between these and the whole house thermostat setting. The work capitalises on primary data from a socio-technical household survey undertaken in a sample of social housing in Plymouth, UK during 2015. The mean reported TRV setpoint temperature in the living rooms (n = 144) and bedrooms (n = 120) were 23.4°C and 22.1°C respectively. This result confirms that occupants prefer cooler conditions in their bedrooms and also suggests that occupants are actively using their TRVs to zonally control their heating at home to maintain comfortable thermal conditions and reduce their heating energy demand. The results also indicate that occupants’ thermostat and TRV setpoint temperatures vary according to their household and motivation, behaviour and perception characteristics. The mean reported thermostat setpoint temperature was 20.7°C for those who reported a living room TRV setting and 20.9°C for those who reported a bedroom TRV setting. This result suggests that there may be a misunderstanding of the purposes of the whole house thermostat and the individual TRVs within a central heating system. Variations in occupant heating control behaviour have an impact on occupant comfort and household energy use. The results of this study have significant implications for the planning and implementation of energy efficiency measures, behaviour change interventions as well as the design of heating controls

Central heating settings in low energy social housing in the United Kingdom

This paper presents essential empirical data on heating setpoint temperatures and durations from UK social housing built to low energy standards. The data was derived from living room air temperature measurements. There were single, double and multiple heating periods per day in the dwellings with mean setpoint temperatures of 20.9°C and 21.0°C on weekdays and weekends respectively. The weekday mean heating duration was 8.4 hours and for weekends, it was 9.1 hours. The results could be used to better inform the assumptions of space heating behaviour used in energy models in order to more accurately predict the space heating energy demands of dwellings

Central heating settings and heating energy demand in low energy social housing in the United Kingdom

This paper compares the central heating settings and the heating energy use performance of six flats and two houses built to low energy standards (Code for Sustainable Homes Levels 4 and 5) with a near identical flat and house built to minimum compliance only (2006 Building Regulations). As low energy houses are only recently emerging in the United Kingdom’s social housing stock, and even fewer are subject to Post Occupancy Evaluation, little is known about their performance in terms of heating behaviour and energy demand. The results show that in general, the mean weekday and weekend setpoint temperatures, heating durations and heating energy use are lower in the low energy dwellings compared to the building regulations dwellings