The impact of control strategies on space heating system efficiency in low-energy buildings

In this study efficiency factors measure the thermal energy performance for space heating. This study deals with the influence of control strategies on the efficiency factors of space heating and its distribution system. An adaptive control is developed and applied to two types of heating curves (linear and non-linear) for a low-energy building equipped with renewable energy sources. The building is modelled with a hybrid approach (law-driven + data-driven model). The model of the floor heating is calibrated and validated by assessing the uncertainty bands for flow temperatures and mass flow rate. Benefits and drawbacks of linear and non-linear heating curves are highlighted to illustrate their impact on space heating thermodynamic behaviour and on the efficiency factors of the space heating system. Practical application: The study reveals that applying commercial building energy simulation software is worthwhile to determine reliable energy performance predictions. Massless building models are not capable of simulating the thermodynamic response of a building subjected to different control strategies. In particular, the application of different heating curves (linear and non-linear) to massless building models leaves the amount of mass flow rate delivered to the space heating unchanged when the building is subjected to sharp variations of the outdoor temperature.