Carbon, Control and Comfort: User-centred control systems for comfort, carbon saving and energy management

Lead Research Organisation: University College London
Department Name: Bartlett Sch of Graduate Studies


Our vision is to engage users in the design of control systems they like, that allow them to create the comfort conditions they want, and which through using the technology and fabric of their homes more effectively, reduces their energy use by 20%. We want to design and test these control systems in a way that complies with utilities' CERT-2 obligations, and provide design, installation and maintenance guidance which allows others to learn from our work and apply it more widely. We estimate this has the potential to save around 3 MT CO2 annually.Homes use about a third of the UK's energy, and produce about a third of all CO2 emissions. Because of the low rates of demolition, and the difference in efficiency between new and old houses, even if every house built from now to 2050 was zero-carbon, the total emissions from the UK housing stock would stay roughly the same. Any significant reductions must come from existing homes. In existing homes, making them comfortable (primarily through heating) uses around two thirds of their energy and carbon. We also know that how occupants' make their home comfortable, through use of the heating system, doors, windows, lighting, the clothes they wear, etc, has an enormous effect on energy use. Identical homes, with different occupants, can vary in energy use by a factor of two to three. Driving your home well can reduce your carbon footprint much more than installing wind turbines or solar panels. Currently, driving your home well is very hard to do. There's almost no feedback on the effect of leaving the bedroom window open at night, or having your thermostat at 21 C rather than 19 C. A quarterly energy bill provides almost no help so occupants' are currently 'driving blind' when it comes to saving energy or reducing their carbon footprint. This project aims to give them something to see with / forms of feedback on the energy costs of their actions which are immediate and in a form they themselves want. We will work with occupants, in their own homes, to understand what they would find useful. Using an action research approach and user centred design methods, we will understand their day to day comfort practices (i.e. how they drive their home) and design systems to help them drive it better, better in terms of comfort, spending less on energy and reducing their carbon footprint. Previous studies show that relatively simple forms of feedback, such as an LCD display showing instantaneous energy use, can help people save 5 to 15%. While these displays are good, they usually only display the total electricity used in the home, not on individual appliances, and they only provide information. In order for people to make changes they need three things: feedback (information on energy use); motivation (the desire to reduce energy use) and choice (the ability to act differently). There is scope to design technologies that provide all three of these - to provide occupants with systems for control that tell them what is using energy, what choices they have to use less, and do to so in a way they like to engage with. An approach targeting all three of these issues, and engaging users throughout the design process, has not been tried before but given previous studies, savings of 20% could reasonably be expected. The research is highly interdisciplinary and is based in field work involving lots of monitoring to ensure the technologies work and deliver real, measurable savings. The research team is a balance of technologists and social researchers and through working closely with householders, utilities and housing providers, we feel we can make a real contribution to understanding how people use energy to make their homes comfortable, and to develop control systems that can help them do this more effectively while saving on energy costs and reducing their carbon footprint.
Description At its heart, the Carbon, Control & Comfort project explored the relationship between occupants, heating systems, the fabric of houses - and how these three things interact to create comfortable environments - and how much energy is used in the process.
This is a complex problem, and in trying to understand it we found just how much variability there is between different households, within different households, and over time. We have found thermostat settings ranging from 15 to 30 degrees C. We found that for most participants comfort and convenience was a far stronger driver of behaviour than cost, although cost was frequently cited as a source of concern. We found that if occupants couldn't intuitively understand their heating system controls they would work around the system, rather than work with it. We found people creating comfort in a diverse range of ways including rugging up, drinking cups of hot tea, and using electric fires' "light only" function as a way of creating a warm ambiance in a room. Surprisingly, we found that only 11% of our social housing participants turned up the heating as their first way of controlling comfort. When they did use central heating controls they used them in many different ways, most preferred to adjust the thermostat directly, some used timers, and some simply turned the whole heating system on and off as they needed it.
We also found surprising interactions between the building fabric and different types of heating systems. We found that for heat-pumps, if you had a house which heats up and cools down slowly, that it could actually cost you more energy to turn down your thermostat at night than to simply leave it running at the same temperature all time. We found that in some types of heat-pump systems that included a hot-water tank outside the house, that these could be losing up to 70% of their energy. We found that for heat-pumps, their efficiency was strongly related to the settings that were programmed into them, as well as how the fabric of the house performed, and user behaviours.
Despite this complexity and variability, we were able to show that if new forms of control worked with occupants' existing patterns of control, that it was possible to save energy and carbon. This tailoring of the form of control, to the context of the occupants, the house, and the heating system, could either be done using "smart" control systems that learned about that particular home and responded accordingly, or it could be done by designing specific kinds of interventions to the needs of that particular home, or by tailoring messages about peoples' energy consumption relative to their peers in ways they could understand and relate to. The key message was that there is no "one-size-fits-all" approach to helping people create comfort and save energy and carbon. The automated form of control that we applied, the Wattbox, which learned about the home intelligently, produced savings of around 10% in the test homes it was applied to. This is a significant achievement, and suggests that for those homes where people aren't actively managing their heating systems, that there could be significant benefits to the application of automated control. Where people are actively managing their heating systems, say through frequent adjustment of thermostat settings, automated control systems are both less likely to deliver savings, and less likely to be accepted by the householders. For this segment of society, provision of feedback systems that help them understand how they're using energy offer the real possibility of allowing them to control their system in the way they like while still helping save energy.
There are lots more findings and recommendations arising from the project along with these that have already, and will continue to be, fed into industry and government decision-making, and we expect these to flow through into better policies and products to help us control our homes in the future.
Exploitation Route The grant finished in 2012 and the findings have been feed into relevant bodies.
Sectors Construction,Digital/Communication/Information Technologies (including Software),Energy,Government, Democracy and Justice

Description The research has benefited the following groups. - Utilities (through E.ON): With findings on the provision of forms of energy feedback to occupants linked to improvements in utilities' customer satisfaction and loyalty, and with evidence that feedback devices are becoming desirable consumer products, and that effective and desirable control systems offer scope to utilities as a means to recruit and retain customers. - Registered Social Landlords (RSLs) and Councils with housing assets through the design guidance on the construction and facilities management of behavioural change control strategies and technologies supported by the appropriate evidence base. - The fuel poor, particularly in low income households through working with occupants of social housing in the design of the control systems, utilities, Registered Social Landlords and councils the researchers to develop control strategies that are suited to this group and validated in this context.
First Year Of Impact 2012
Sector Construction,Energy,Government, Democracy and Justice
Impact Types Societal,Policy & public services