Do in-home displays affect end-user consumptions? A mixed method analysis of electricity, heating and water use in Danish apartments

Reducing building energy consumption is of foremost importance to achieve energy and environmental sustainability. However, upgrading the physical properties of the buildings alone may not be enough to reduce their energy consumption, since occupants’ behaviour is a determining factor on the real consumption of a building. In this regard, the use of in-home displays (IHDs) can represent a valid help for increasing user awareness, while also preventing the so-called rebound effect. Recent studies have questioned the estimates of benefits of IHDs available in the literature. In this context, the aim of this work is to provide detailed qualitative and quantitative analyses of the effect of IHDs on more than 200 apartments in four Danish buildings. The consumptions of heating, electricity and water were monitored along with the tenants’ use of the IHDs. Qualitative research methods were used to provide context to the quantitative findings and helped explaining the findings of the quantitative analyses. The qualitative research activities began in September 2015 and continued until October 2019, while the energy monitoring campaign was performed in the period December 2016 – June 2019. In one building, the screens did not work for more than a year after installation. When the IHDs started working in this building, the average consumption of cold water, hot water, electricity and heating decreased by 17%, 23%, 12% and 17%, respectively. End-user interviews supported this and found a positive impact of the IHDs. There was no correlation between the residents' level of interactions with the IHDs and the consumption.