Turning up the heat on obsolete thermostats: A simulation-based comparison of intelligent control approaches for residential heating systems

This article provides an overview and quantitative evaluation of the performance of heating control approaches for residential buildings. First, heating control technologies discussed in the literature are reviewed and conceptualized in a taxonomy of eight archetypical control approaches. Subsequently, the performance of each heating control approach is evaluated in terms of energy consumption and comfort for occupants. For this evaluation, data on in-room temperature, heating behavior and occupancy patterns of households in Southern Germany was collected over a 14-month period. Integrating this data into a building simulation, the performance of each control approach was evaluated on a per household basis. Based on this evaluation, we find that control approaches applying automated setpoint variation (i.e. intelligent) outperform scheduled setpoint variation such as programmable thermostats. Compared to simple on-off control without temperature setpoint variation, we find median energy savings potentials in the range of 21–26% and observe higher thermal comfort compared to programmable thermostats. Our findings point to the efficiency improvement potential of intelligent heating control, in particular for old buildings and households with high vacancy times. Because of the comparatively low initial investment and high energy savings potential, the results suggest that policy should extend its focus from retrofitting heating systems and building insulation towards more efficient energy use enabled by intelligent control.