Full Description

One of the challenges with dynamic facades is how to balance the need for daylight versus reducing overall energy use while ensuring comfort for the occupants. This requires detailed knowledge of the solar optical properties of fenestration, which affect the transmission of solar gains and daylight. This paper first provides an overview of current approaches for modeling solar optical properties of roller shades, including advantages and limitations. Then, integrating sphere measurements were conducted to determine the detailed solar optical properties of different products. The results are compared to previous findings and provide useful information about direct-direct, direct-diffuse and angular properties of roller shades, depending on openness factor and color.Finally, the impact of detailed solar optical properties on energy performance and glare is evaluated using annual simulation results for different fabrics. The results show that detailed shading properties should be used for a more realistic evaluation of the impact of shading on daylighting and visual comfort.

Citation: ASHRAE Papers: 2015 ASHRAE Annual Conference, Atlanta, GA