Modelling the impact of user behaviour on heat energy consumption

Our behaviour in our homes can seriously affect the associated carbon dioxide (CO2) emissions. In the UK, space-heating accounts for nearly 60% of domestic energy consumption and 27% of total CO2 emissions come from our homes. Regrettably, low-energy building design does not guarantee low-energy performance. Controls systems, in particular heating controls, are often too complex for users to programme. This study uses real-world data from buildings, observational data from users and energy modelling to establish why people have difficulty using their control systems, and the potential resultant energy impacts.

Users were asked to programme an example heating profile for a week using three different control interfaces. Prior to attempting this task there was a preconception amongst users that they would be unable to complete it. Controls were found to exclude users due to the cognitive demands placed on them. A key observation was that five of the twenty-four users made a mistake in the programming process, which meant that the heating temperature was not reduced at the end of the heating period. This could potentially result in accidental heating throughout the day and night, unbeknown to the users.

Modelling this observation showed an increase in heating energy consumption of 14.5% compared to energy consumption associated with successfully programming the example heating profile. The modelling results showed that successful programming of the profile consumed less energy (in two of the three scenarios) than the default settings of the heating controls. Increasing the sense of perceived control users have over their environment may enable them to use less heat energy. By designing controls so that pro-environmental behaviour is, easily accomplished substantial energy savings could be made.