Light Pipe Comparative Study

Results of daylight illuminance measurements of the field testing of two light guides with different roof installations is presented in the article. The first one is a common tubular system with a glass roof dome and the second one is a new light guide prototype with a concentrator head. The daylight illuminance was measured in a test chamber with the light guides installation. The measurements were carried out at the end of a summer season from August to September 2017. The measured data show differences in the daylight illuminance of the two tested light guides. The measured data were compared with simulation outputs in software Holigilm. In summary, it was found that the common light guide is about 37 percentage more efficient in light transmittance compared to the new light guide prototype. In temperate climate with dominant cloudy and partly cloudy daylight conditions the common light guide transmitted more light that the device with the concentrator head which reduced light transmission much more.