Positive Energy Houses, envelope and systems integrated optimization by means of dynamic simulations

In the framework of the Interreg IV-A Greater Region project called « VallEnergie » four projects of residential houses with “positive energy performance” were analysed. The main purpose of the study was to define the optimal choices in terms of envelope and energy system in the building in order to reach the high performance level of a “Positive Energy House” (PEH in this paper). The first step was to determine what was meant by the term “Positive Energy House” and to define criteria used to characterize energy and comfort performance of such house.
The concept of « Positive Energy house » defined in the project had to be in adequacy with European definition, therefore a complete state of the art of NZEB concept in Europe was carried out. The collected information was used to establish the specifications document of “PEH” in concertation with the project consortium. By means of TRNSYS17 software different sets of variants were assessed by thermal dynamic simulations and compared in order to define the optimal choice of insulation strategy and heating, DHW and Renewable Energy production systems configuration to reach the PEH performance as defined in the specification document of “VallEnergie” project. The paper will present the selected hypotheses of the simulation models, describe the applications that were developed in TRNSYS and discuss the results of the different variants.