Daylighting performance evaluation of a bottom-up motorized roller shade

• Published in: Solar energy Vol. 84; no. 12; pp. 2120 - 2131
• Main Authors: Kapsis, K., Tzempelikos, A., Athienitis, A.K., Zmeureanu, R.G.
• Format: Journal Article
• Language: English
• Published: Kidlington Elsevier Ltd 01.12.2010; Elsevier; Pergamon Press Inc
• Subjects: ALGORITHMS; Applied sciences; Building technical equipments; Buildings; Buildings. Public works; Computer simulation; CONTROL; CORRELATIONS; Daylight; DAYLIGHTING; Electric lighting consumption; Energy; ENERGY CONSERVATION; ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATION; EVALUATION; Exact sciences and technology; ILLUMINANCE; Illumination; Lighting; Lighting systems; Natural energy; OFFICE BUILDINGS; Offices; OPTICAL PROPERTIES; ORIENTATION; Outdoor; Rollers; SENSITIVITY ANALYSIS; Shades; SHADING; Shading control; SIMULATION; Solar energy; Solar radiation; SUN SHADES; WINDOWS; Work plane illuminance; Work plane illuminance; Daylighting; Electric lighting consumption; Shading control; Natural lighting; Performance evaluation; Sensitivity analysis; Buildings; Experimental study; Algorithm; Energy savings; Daylight; Window blind; System simulation; Shadowing
• ISSN: 0038-092X; 1471-1257
• DOI: 10.1016/j.solener.2010.09.004

This paper presents an experimental and simulation study for quantifying the daylighting performance of bottom-up roller shades installed in office spaces. The bottom-up shade is a motorized roller shade that opens from top to bottom operating in the opposite direction of a conventional roller shade, so as to cover the bottom part of the window, while allowing daylight to enter from the top part of the window, reaching deeper into the room. A daylighting simulation model, validated with full-scale experiments, was developed in order to establish correlations between the shade position, outdoor illuminance and work plane illuminance for different outdoor conditions. Then, a shading control algorithm was developed for application in any location and orientation. The validated model was employed for a sensitivity analysis of the impact of shade optical properties and control on the potential energy savings due to the use of daylighting. The results showed that Daylight Autonomy for the bottom-up shade is 8–58% higher compared to a conventional roller shade, with a difference of 46% further away from the façade, where the use of electric lighting is needed most of the time. The potential reduction in energy consumption for lighting is 21–41%.