High Fidelity CFD Modeling of Natural Ventilation in a Solar House

Natural ventilation is an important factor in the design of sustainable buildings; it has the potential to improve air quality, while providing thermal comfort at reduced energy costs. Computational fluid dynamics (CFD) simulations provide comprehensive information on the internal flow pattern and can be used as a design tool. The present work offers insight of natural ventilation in a fully functional building, namely, the solar facility Interlock House in Iowa. Ventilation in the house is studied during summer months with some of its furniture included. The results show quantitative agreement between numerical simulations and experiments of vertical temperature profiles for each room. The temperature profile of the room with the inlet opening shows a more pronounced temperature variation. Flow patterns show higher velocities near the walls and marked flow circulation towards the opposite side of the building. The purpose of this work is to validate the numerical model that predicts airflow distribution for different configurations. INTRODUCTION Almost 40% of the energy usage in the US is utilized in buildings and about 48% of that usage corresponds to heating and cooling. Natural ventilation is an important factor in the design of sustainable buildings; it has the potential to improve air quality, while providing thermal comfort at reduced energy costs. Although the benefits of natural ventilation make it an attractive alternative, as wind and thermal energy are free resources, a good ∗[email protected] understanding of the physics of ventilation is necessary given the difficulty in being able to control such available resources [1]. In 1999, Linden [1] discussed the fluid mechanics of natural ventilation explaining the effects of windand buoyancy-driven flows due to temperature variations by exploring mixed and displacement ventilation. In the last decades many studies have been performed to better understand the flow behavior in natural ventilated buildings. Some of the methods used to study ventilation in buildings include analytical modeling, experimental models performed in small scale and full scale buildings, zone network models, and computational fluid dynamics (CFD). According to Chen [2], who summarized the methods utilized to predict ventilation performance, CFD was not only the most popular, but the most accurate and reliable modeling method. CFD is mainly to study natural ventilation, indoor air quality, and stratified ventilation, which is hard to predict with the other methods. Different CFD applications include commercial and residential buildings, health care, industrial, and agricultural facilities, as well as schools, and public transportation vehicles. CFD simulations has extensively been used to study natural ventilation flows because it provides comprehensive information on the flow pattern inside buildings and parameters to calculate comfort and efficiency. CFD can also be used as a tool to explore different ventilation scenarios and determine optimal configurations, loads, and operation conditions. Bastide et al. [3] used a combination of zonal models and CFD to investigate thermal comfort in tropical climates and reduce air-conditioning usage. Many studies have focused on numerical models, especially to determine the appropriate turbulence model. Jiang and Proceedings of the ASME 2015 International Mechanical Engineering Congress and Exposition IMECE2015 November 13-19, 2015, Houston, Texas