Airflow investigation of fabric membrane forms: a fluid dynamic analysis for thermal comfort

2013-05-31In the current building industry, fabric membranes are often a choice construction when structural behavior, geometry, and cost are determining factors. Environmental performance is only considered an added benefit, and the research and analysis is commonly an afterthought. As fabric membranes become more present in the modern building industry, their environmental performance qualities need to be further evaluated and measured against energy standards. They offer unique performance qualities in the metrics of daylighting, solar radiation, and possibly acoustics. A limited amount of research has been conducted in how fabric membranes can enhance natural ventilation and occupant thermal comfort, but it can be proposed that when studying airflow patterns, fabric membrane structures will also behave differently from a static building material. Furthermore, they will improve human thermal comfort as a result of their unique anticlastic geometries. ❧ This thesis examines what airflow patterns occur within fabric membrane structures and how architects and engineers can use these forms to enhance occupant thermal comfort in their designs. The study assesses four basic fabric forms serving as shades over a pedestrian area through airflow patterns, air velocities, temperatures, humidity, Predicted Mean Vote (PMV), and Predicted Percentage of Dissatisfied (PPD) in three different climates: hot and humid, temperate, and dry and arid. The metrics were measured in terms of human comfort defined by ASHRAE Standard 55 and ISO 7730