Brise Soleil, a French term meaning “sun breaker”, refers to an architectural feature and shading device designed to control the penetration of sunlight into a building while maintaining visual transparency and aesthetic appeal. These shading devices – for which Contrasol specialise in designing, manufacturing and installing – are a modern and sustainable solution for both commercial and residential buildings for their ability to enhance occupant comfort by optimising natural lighting, reducing glare and most importantly, reducing solar heat gain. The additional benefit of reducing solar heat gain is minimising or even removing the requirement for mechanical cooling, making for a more energy efficient building.
In this article, our second published online as part of Contrasol’s new blog, we will explore the concept of sun paths, the importance of fin orientation and how brise soleil systems effectively integrate these elements to create a harmonious and efficient architectural shading solution.
Understanding Sun Paths
The significance of fin orientation in relation to brise soleil design is dictated mainly by sun paths, which varies throughout the day as well as the time of year. The path the sun follows, is defined by two aspects: azimuth angle and the altitude angle. The azimuth angle represents the sun’s position in relation to true north measured in degrees. It ranges from 0˚ (due north), with 90˚ indicating due east, 180˚ representing due south and 270˚ indicating due west. The altitude angle, measured in degrees, indicates the angle of the sun above the horizon. The integration of sun paths into computational simulations of a building with the brise soleil allow architects and designers to assess the effectiveness of the brise soleil throughout the year.
Optimising Fin Orientation
Brise soleil systems usually consist of a series of fins or louvres attached to the facade of a building. These fins can be mounted in various configurations, either vertically, horizontally or projecting from the building façade and it is this fin orientation which is crucial for a well-designed and effective brise soleil. By considering the sun’s path at a particular location, architects and designers can strategically position the fins to provide optimal shading and daylight control. For example, the use of vertical bays or fins on the east and west-facing facades are effective in shading a building during the early and late part of the day respectively, when the sun angle is low. Southern elevations are more effectively shaded by horizontal or projecting brise soleil as they receive higher sun angles.
By using the location and orientation of the building, Contrasol can garner accurate data on the sun’s position at different times of the day and year, allowing for precise placement and orientation of fins for optimal brise soleil design for any commercial or residential building. By angling the brise soleil fins appropriately, they act to block a significant portion of direct sunlight thereby reducing solar heat gain and preventing excessive heating of the building’s interior. Properly aligned fins can also selectively diffuse sunlight to filter natural light into a building whilst minimising direct glare. This then reduces the need for artificial lighting during daylight hours, acting to reduce energy consumption and promote sustainability.
Brise soleil therefore serves as an ideal shading solution that harmonises the need for natural light, glare reduction and solar heat gain control, providing a pleasant environment for the building occupants.