Upgrading a Broad Area Illuminating Integrating Sphere and Solar Transmittance Measurement of a Sheer Blind

Integrating Sphere;Sheer Blind;Transmittance;Mechanical Engineering

Halder, Victor

University of Waterloo

关键词: Integrating Sphere;    Sheer Blind;    Transmittance;    Mechanical Engineering;   

Others  :  https://uwspace.uwaterloo.ca/bitstream/10012/3593/1/Victor%20Halder-MASc%20Thesis.pdf

瑞士|英语

来源: UWSPACE Waterloo Institutional Repository

【 摘 要 】

Shading devices are frequently used to control solar gain through windows. Solaroptical properties are very important in the energy analysis of windows. Transmittance,absorptance and reflectance are required to quantify solar heat gain throughcomplex fenestration systems, which consist of combinations of glazing and shadinglayers.In this research the solar transmittance of a sheer blind was measured using aBroad Area Illuminating Integrating Sphere (BAI-IS). More specifically, the spectraldirectional-hemispherical transmittance was measured in the wavelength rangeof 0.4 µm to 2.0 µm.A ;;sheer blind” consists of soft fabric vanes, similar to a venetian blind, suspendedbetween two vertical layers of sheer fabric. This arrangement is popular because it is attractive and it has potential application for daylighting. The vertical sheer fabric reduces the solar intensity and diffuses incident radiation; generally reducingsolar gain and producing soft, natural illumination. The fabric vanes controlthe amount of light entering the room.Shading devices such as venetian blinds, sheer blinds and drapes have spatiallynon-uniform and light scattering surfaces. Hence, measurement error occurs ifthe solar optical properties are measured by traditional narrow-beam measurementtechniques typically used in commercial spectrophotometers. To reduce this error,a BAI-IS is recommended.The BAI-IS apparatus consists of a 20-inch diameter integrating sphere, samplemounting system, monochromator, radiant source, lock-in-amplifier, photo sensor,optical chopper and various auxiliary devices. In order to improve reliability of the measurement the BAI-IS has recently been upgraded by replacing most of the keycontrol and measurement equipment.The refurbishment of the BAI-IS apparatus was successful. The directionalhemisphericaltransmittance of a sheer blind from BAI-IS measurement was found to agree well with an analytical model.