IBPSA2013

Green roofs and green walls have several benefits on buildings and cities. They are most often used for water management and for the aesthetical value they provide to the urban environment. These green coatings have a positive impact on the sustainability of building materials. They can improve building energy performance and reduce the amplitude of diurnal variations of the surfaces temperature in summer. The energy saving or comfort improvement is more obvious for hot climates. This paper presents a green envelope model integrated in a transient building simulation program (TRNSYS).

The analysis of the hygrothermal behaviour of green building materials is investigated in this work. For this, a 1D heat, air and moisture transfer model was developed using Comsol Multiphysics® and applied to a hemp concrete wall. Particular attention is paid in the experimental determination of hygrothermal properties and their dependency with the temperature and the moisture content. To validate the model, a hemp concrete wall was monitored for 12 month under various boundary conditions.

Commonly provided HVAC system simulation tools are not necessarily satisfactory for the investigation of operational improvement and renovation planning because the effectiveness of using a large amount of measurement data accumulated in a Building Energy Management System (BEMS) is limited.

Energy performance of a university building is mod-eled and compared to the actual measured perfor-mance of the building. Two energy models are devel-oped in this work: design model and as-built model. The design model is based on the input parameters calculated by a consulting company for LEED submis-sion. The as-built model is built using different input parameters for envelope performance and occupancy. The impact of these parameters on the simulation re-sults are reported and discussed.

This investigation studied an adjoint method to achieve the optimal design of ventilation in enclosed environment and validated it by two-dimensional cases. This study defined a part of the flow field and/or temperature field as the design objective and determined the thermo-fluid boundary conditions as the design variables. By using the adjoint method together with the optimality condition that was implemented in OpenFOAM, this investigation could find the optimal air supply parameters.