Optimal window area of a kinetic facade to provide daylight in an office building in Tehran.

Window to wall area ratio (WWR) is an important parameter that greatly affects the energy efficiency of a building. The aim of this research is to achieve the optimal level of the window area together with a squared geometry rotational kinematic model having horizontal axis in the south facade of an office building in Tehran.In order to evaluate the indoor daylight level, dynamic daylight indicators with WWR from ۵۰ to ۹۰ % and facade kinematic model have been simulatted using Grasshopper tool and Honeybee Plus plugin version ۰۶ and Ladybug Lbt version ۱.۵.۰. through parametric simulation were studied parametric. First kinetic facade and its movement structures are introduced, then the daylight indices and the required lighting level for an office space have been discussed. The simulation is carried out using two models of optical and thermal properties in the office building, where in the base model, the ratio of the optimal WWR is up to ۶۰%, for a facade with a square geometric model and a rotating kinematic model with a horizontal axis.To optimize the results, the reflection coefficients of the floor, wall, the visual transmission coefficient of the glass and the viewing angle (۴۵ to ۹۵ degrees) were parametrically studied. The results showed that on the south facade of the office building in Tehran, using a kinetic facade with a rotational kinematic model and horizontal axis, the optimal WWR is ۵۰%.

Keywords:

window to wall ratio , kinetic facade , kinematic model , dynamic daylight , Simulation