Reducing domestic energy consumption through inclusive interface design

Abstract

With housing in the UK responsible for over a quarter of all building related carbon dioxide (CO2) emissions, it is becoming increasingly difficult to ignore the impact of occupant behaviour on such emissions. One area where occupant behaviour contributes largely towards emissions is space heating within domestic buildings. Despite technological improvements in the efficiency of heating systems, controls have become increasingly complex. Hence, there is a need to enable people to use their heating controls effectively in order to help reduce the associated CO2 emissions. This research found that significant numbers of people were excluded from using digital programmable thermostats, in particular people over 50 years old. The first study examined the scale of exclusion relating to digital programmable thermostats installed at a specific housing development. A second study explored in detail the reasons for exclusion from successfully programming a range of digital programmable thermostats. This was an in-depth usability study of heating controls that focused on the usability issues experienced by older people and was published in the Journal of Engineering Design. Based upon the outcomes of the first two studies a more inclusive heating control interface prototype was developed. The prototype demonstrated a reduction in both cognitive demands and associated user exclusion. Task success rates increased by 56.3% amongst older participants, and detailed energy modelling indicated that energy savings of 14.5-15.6% annually could be achievable. This work suggests that a more inclusive heating control interface could enable energy savings in the region of 15% through reducing the cognitive demands. Furthermore, this research challenges the existing paradigm and shows that inclusive design research may contribute to sustainable development in an environmental, as well as social, capacity.