building simulations

Building simulations are used to investigate building performance and design the building systems optimally. In particular, the air exchange between zonesand with the environment has a pivotal role inmodernventilation system design. Nevertheless, the model of the airflow becomes difficult for the modeler, motivated by the complexity of the grid that has to be modeled. IDEAS, a Modelica library, includes components for thermal multi-zone models of buildings as well as models for heating, ventilation, air conditioning and other elements that interact in the same model.

This paper presents a parametric study on the effect of different TMY (Typical Meteorological Year) datasets on the results of energy dynamic simulation. The analysis was carried out running the software Design Builder with EnergyPlus code on a sample residential building located in three Italian cities and using two different TMY data sets: EnergyPlus and CTI (Italian Thermo- Technical Committee).

Mixed-mode ventilation uses intelligent switching between natural and (partly) mechanical ventilation modes to find the best possible balance between indoor air quality, user comfort and energy consumption. It applies demand-control at the level of the operating mode depending on the constraints imposed by the building, its users and its surroundings. Although mixed-mode ventilation is said to have the potential to achieve a comfortable and healthy indoor environment while achieving significant energy savings, it is rarely used in practice.