Estimation of the Heating Time of Small-Scale Buildings Using Dynamic Models

Most buildings are not continuously occupied, such as office buildings, schools, churches and many residential buildings. Maintaining comfortable conditions only during the occupied periods reduces the energy costs. This can be done by lowering the temperature as much as possible during unoccupied periods and at nights and then raising the temperature for occupation. More energy can be saved by using this method. The estimation of the time taken for the temperature increase is important in determining the optimal time for switching the heating equipment on. A dynamic model for single-zone buildings is developed for estimating the heating time, and the model is validated using four case studies with real measurements. The model computes the heating time with an error of less than 3%. It can also be used to obtain a rough prediction of the space heating energy use. Further, it was observed that starting the heating at the right time returns the lowest energy cost with the introduction of usage-based energy tariff systems. The model is quick in predicting the results, and hence, physics-based models can play an influential role in building system control with advanced control strategies.