Search

The electrification of heating and transport and decarbonisation of supply creates a need for demand side flexibility to balance the grid. Heat pumps are expected to form a major part of heat delivery, and many modelling studies have investigated the technical potential of heat pump demand response. However, little empirical work has been reported on the practical implementation of such demand response in occupied homes. This paper presents a cross-case comparison of three early adopters of heat pump demand response in the UK. The aim was to reduce heat pump electricity consumption during the same peak period, but each employed a different control strategy: lowered air temperature setpoints, lowered flow temperature and blocked heat pump compressor. A 56–90% electricity reduction during the peak period was observed; the success of the demand response depended on how the control strategy affected the heat pump and the rest of the heating system. However, no one stakeholder is responsible for all these system components. The fabric, heating distribution and control system and heat pumps installed are highly heterogeneous across the stock, highlighting that flexibility mechanisms must be developed that can be tailored to or work across their range. Three case studies of different heat pump demand response control strategies in real homes are presented. All three households reduced their electricity consumption during a peak period but delivered unintended consequences where the heat pump’s logic did not correspond to the demand response requirements. This study highlights that the implementation of heat pump demand response to support electricity system operation requires a clear definition of electricity system need as well as practical demand response mechanisms to be integrated into heating system design.

In homes in the UK, it is very common to operate space heating intermittently; the heating is usually switched off when the occupants are asleep at night and when they are out during the day. The strong association between heating operation and household routines leads to a morning peak in demand which, if it persists following electrification of heating, will require significant reinforcement of electricity supply networks. This paper examines factors that underpin how heating is used in the UK. A unique dataset of heating controller settings from 337 UK allows investigation of how patterns of heating operation in individual homes contribute to daily patterns of space heating energy consumption at the group level. A mixed method approach is followed, combining quantitative analysis of data with interviews with householders. The concept of thermal routines is introduced, bringing a time dimension to the consideration of domestic thermal comfort and recognising that demand for space heating is linked to patterns of practices in the home, which are themselves linked to social routines, e.g. timing of work and school. The results from this study suggest that household thermal routines around 07:00 in the morning are a particularly important consideration for a transition to future energy systems with a high proportion of low carbon heat. Factors that currently limit flexibility of heating demand in the UK are identified, and the implications for a transition to low carbon heating sources are discussed.

The increasing potential for dramatic climatic changes, the need to protect the future of our energy supply and rising fuel prices, mean that there is an urgent need to reduce energy consumption. This Special Issue of Indoor and Built Environment on ‘People and energy use in the indoor and built environment’ recognises that while buildings account for 32% of total global final energy use, the role of people in buildings’ energy use is often overlooked, despite the fact that ‘buildings don’t use energy: people do.’ The papers in this Special Issue demonstrate a broadening of the social science contribution to understanding energy use in the indoor and built environment. As well as focusing on ‘routine actions’ (or behaviours) using technologies and buildings, many papers presented here focus on ‘one-off actions’ to change technologies or buildings. Several papers go beyond a focus on individual building occupants, to include chains of actors or intermediaries (e.g. landlords) that influence the choice and/or use of technologies or buildings. These papers often also address the processes or chains of actions entailed in introducing new technology or buildings – such as service design or the communication process. Many papers explore the social, economic or technical context for actors and their actions. Most papers explore motivations for actions. Indeed, for many authors in this Special Issue, context is motivation and, combined with existing technologies and buildings, it creates the conditions that virtually require the routine actions that are observed. A few papers report on experiments with relatively ‘deep’ interdisciplinarity; approaches that might help the social and technical sciences learn from each other and so improve our understanding of people and energy use in the indoor and built environment. Three papers focus on the use of technology. Moore et al. note that the installation of heat pumps into homes has traditionally been seen as a purely technical matter, but if heat pumps are not used effectively, they won’t save energy. Examining the installation of domestic heat pumps in UK social housing, they focus on the design of the service to support the user experience of this new technology. Landlords and installers thought heat pumps were too complicated for users and more complicated than necessary. Tenants felt they were given insufficient information on how to use their heat pump, and many lacked confidence using heat pump controls, resulting in feelings of frustration and dependence. However, the authors’ prototype leaflet on using the heat pump controls was not favourably evaluated by users and tenants wanted a personal follow-up visit from the landlord or installer to answer any questions. Belatedly trying to explain how to use a too-complicated technology seems a less-promising approach than developing a technology and its control interface to suit its users. Dimitrokali et al. also examine the use of technology – smart home heating controls. Participants were customers of a UK utility company who volunteered to take part; nearly all were men who felt they had a good understanding of the purpose of smart home heating controls. Participants felt the trial positively changed their heating behaviour but wanted better capacity to control schedules when away from home and personalised tips on how to control their heating. The use of technology is also explored by Watson, focusing on a recently built UK ‘passive design’ office development, featuring a range of natural ventilation technologies and newly inhabited by a tenant organisation. The building was using significantly more energy than predicted, even after a post-occupancy evaluation helped fine-tune the technologies. The author uses social practice theory to understand this ‘performance gap’. Although the material element (technologies) of social practice theory was eventually functioning correctly, this was not the case for the three other elements of the practices framework: embodied habits, engagement (developing shared meaning) and institutionalised knowledge. The habits of building users were deeply

Targets for energy performance in operation have been advocated as a solution to the well-documented mismatch between the expected and actual energy use of buildings. Although construction industry actors will be crucial in realising these targets, their response to them is currently under-explored. Augmenting research on how middle actors shape energy consumption, this paper examines how everyday talk in the construction industry sustains this mismatch, drawing on a study of a hospital construction project with targets for energy in use. It applies Gilbert and Mulkay's approach to discourse analysis, particularly their interest in “accounting for error”, to data drawn from interviews with actors across the construction project, observation of daily life on site, and an examination of written interactions. Findings show how actors make a discursive division between the “theory” and “reality” of energy use. Expressing scepticism about “theory”, in particular, allows them to rationalise problems with future operational energy consumption and thereby mitigate their professional liability. This division therefore perpetuates, rather than overcomes, the separation between energy in design and operation, displacing a more collaborative discussion of performance expectations. This challenges the assumption that targets for energy in use can be effective without accompanying changes in industry incentives and ways of working. This paper argues for more attention to the patterns of talk that are found in the construction industry, in order to uncover how this crucial set of actors will respond to new energy policy incentives.

Building energy research has historically overlooked the role of attitudes, instead focusing on building and socio-demographic influences. Even when attitudes are measured, usually, the attitudes of just one household member are measured even though household energy consumption is the result of actions of all household members. This research explored first whether attitudes could help explain heating usage and second whether the attitudes of a couple could explain more of the variability in heating behaviour than the attitudes of one partner. The attitudes towards home heating energy use (i.e. attitudes towards thermal comfort , economical with energy , industry and technology ' s role and individual ' s role ) of 128 English couples were used in this study. Together with building and socio-demographics, attitudes were examined to explain heating temperatures and durations, which were derived from temperature sensors placed in the homes in 2007–2008. The results showed that attitudes helped explain heating temperatures and durations, even when building and socio-demographic variables were controlled. Economical with energy was the most highly identified influence on heating behaviours, with thermal comfort a close second. In households that included a couple, combined attitudes of both partners explained heating usage behaviours more accurately than the attitudes of either male or female only.

Heating patterns and temperatures are among the most important determinants of English home energy use. Consequently, building stock models, widely used for informing UK energy policy, are highly sensitive to the assumptions they make on how occupants heat their homes. This study examined heating patterns in English living rooms and compared them to model assumptions. A time-series of winter spot temperature measurements was translated into statements of the heating system being on or off during weekdays and weekend days, and the heating demand temperature estimated. The analysis showed that weekdays and weekend days are far more similar than commonly assumed. Contrary to model assumptions, homes were frequently heated outside assumed heating hours and not all homes were heated at the same time or followed the same pattern. The estimated demand temperature was about 20.6 °C, and the average temperature during heating periods was about 19.5 °C, both lower than the commonly assumed 21 °C used in models. Significantly, variability between homes in demand temperature and hours of heating was substantial. The results indicate the need to revisit some assumptions made in building stock models, and to take account of variability between homes when aiming at predicting space heating demand for an individual home.

Objective This study examines the extent that temperatures in English living rooms correspond to standard assumptions made in established UK building stock models. Methods Spot temperature measurements taken every 45 min over 92 winter days in 248 homes in England were analyzed and compared to the assumed thermostat setting of 21 °C inside and outside the assumed heating periods. Results Homes on average displayed lower internal temperatures during assumed heating periods and significantly shorter durations of heating to 21 °C than common models assume, with about 20% of homes never reaching the assumed demand temperature of 21 °C. Data showed a difference of only about 45 min in the duration of temperatures at or above the demand temperature for weekdays and weekends, contrary to the assumed difference of 7 h. Variability between homes was large. Conclusion These findings suggest that currently used standard assumptions of heating demand and heating duration do not accurately reflect the living room temperatures of dwellings in England. Practice implications Standard assumptions might have to be revised, in particular regarding the weekday–weekend differentiation. The prediction of internal temperature for a given home contains potential large error when using standard assumptions.

Rising demand temperatures are widely blamed for UK home energy use not declining over time despite the increased efficiency of dwelling envelopes and heating technologies The hypothesis that thermostat settings have risen over time is tested using a repeated cross-sectional social survey of owners of centrally heated English houses No statistical evidence for changes in reported thermostat settings between 1984 and 2007 is foundWhy then has home energy use not declined over time despite homes apparently becoming more efficient? There is evidence that the energy efficiency of homes has not improved as much as previously assumed Improvements in dwelling energy efficiency and increased penetration of central heating would have increased internal temperatures without occupants demanding higher temperatures Dwelling area heated or duration of heating or window opening during the heating season may have increased over time increasing temperatures or energy use

Crucial empirical data (currently absent in building energy models) on central heating demand temperatures and durations are presented. These data are derived from the first national survey of energy use in English homes and includes monitored temperatures in living rooms, central heating settings reported by participants, along with building, technical, and behavioural data. The results are compared with model assumptions with respect to thermostat settings and heating durations. Contrary to assumptions, the use of controls did not reduce average maximum living room temperatures or the duration of operation. Regulations, policies, and programmes may need to revise their assumptions that adding controls will reduce energy use. Alternative forms of heating control should be developed and tested to ascertain whether their use saves energy in real-world settings. Given the finding that detached houses are heated for longer, these dwellings should be particularly targeted in energy-efficiency retrofit program...