Validation of a TRNSYS model for a complex HVAC system installed in a low-energy building

As the energy consumption in buildings sector is rapidly increasing, the need of concrete actions to be undertaken arises. An important measure with this respect is developing accurate models, used for analyzing strategies of energy intensity reduction. This paper focuses on developing a proper white-box mathematical model used to predict the energy behavior of a low-energy dwelling, built using the Passivhaus standard and placed in Bucharest, Romania. The model was developed using TRNSYS and was created from simple to complex, starting with the HVAC system (composed of an EAHX - earth to air heat exchanger, a MVHR - mechanical ventilation with heat recovery and an ER - electric resistance) and then integrating it within the building's framework. Moreover, each sub-model was first calibrated and validated using data gathered by the building's monitoring system. The model was then extended to analyze the indoor comfort and the energy consumption for heating the building. Finally, this complex model was used to simulate the behavior of the test house in other climatic regions from Romania to see if construction standard and the implemented HVAC system are still efficient. Thus, the model was run for six cities spread throughout the.