How to represent opaque ventilated facades in building energy simulation: a comparative study between three strategies

um estudo comparativo entre três estratégias

Abstract

Modeling the opaque ventilated facades in buildings energy simulation software is a challenge, as this technology allows an infinity of constructive configurations, making simulation necessary to verify the efficiency of its thermal performance in each case. This work aims to present a strategy for modeling opaque ventilated facades in building energy simulation software, EnergyPlus. The study was carried out based on the comparison of temperature values obtained from the simulations, through three ways of simulating the natural ventilation of the cavity, with data measured and published in another paper. The method comprises 3 steps: selection and definition of the model to be studied based on a reference article; computer simulations with different EnergyPlus modules and finally, comparison between the models with statistical indicators. Modules are parts that make up the program structure and allow the calculation of the energy required for heating and cooling a building using a variety of systems and energy sources.  The chosen modules were: Exterior Natural Vented Cavity, Wind and Stack Open Area and the Airflow Network. The results indicated that the program´s module for naturally ventilated air cavities simplifies some important data, mainly regarding the surface temperatures of the external material. The other modules performed very similarly, with Airflow Network obtaining the highest correspondences between measured and simulated values.