A simplified hourly calculation code to evaluate the buildings heating load: A case study for Italian climatic conditions

The spread of novel smart grids in urban environments requires the development of intelligent platforms for the rational exploitation of energy resources in buildings. For a given locality, the possibility to know in advance the climatic data with a high reliability index, makes possible the predictive evaluation of thermal loads in buildings. The predicted thermal loads evaluation allows a better management of the heat generation systems, with corresponding operation economies. Climate data, geometric and thermo-physical characteristics of a building envelope are usually employed in dynamic simulation codes in order to determine the thermal loads. These codes are characterized by a high complexity index, with interfaces difficult to understand and usually require high computational time. In this paper, a dynamic model with lumped parameters and easy to understand, developed also for non-expert users, is presented. Regarding a residential building of usable area of 100 m2, in function of climate data of South Italy, the thermal load profiles and indoor air temperature were determined with the mentioned model implemented in JAVA environment. The results were compared with the TRNSYS code that uses the transfer function method approach. Good agreement between the obtained results was observed, especially for buildings with high thermal inertia