Abd. Moksin, Mohd Maarof

Abdul Wahab, Mahdi

Saion, Elias

Sulaiman, Zainal Abidin

Universiti Putra Malaysia Institutional Repository

TRANSMISSION OF OPTICAL SOLAR RADfATIONFOR Category F10600: Applied Sciences and TechnologiesElias Saion, Mohd. Maarof, H.A. Moksin,Mahdi Abdul Wahab and Zainal Abidin SulaimanFaculty of Science and Environmental StudiesUniversiti Putra Malaysia, 43400 UPM, Serdang, Selangor,MalaysiaKeywords: solar radiation, mirror light pipes, transmis-sion of light.IntroductionThis research work covers the development. characterisationand application of transmission of the mirror light pipes(MLPs). A MLP consists of a metallic reflective closed wallstructure with highly transparent open ends. Light falling onthe entrance is transmitted through the pipe to the exit bymultiple reflections off the reflective inner wall and used atthe exit. Currently. the MLPs have been constructed using3M silverlux™ plastics and the characteristics of the pipeshave been studied.Materials and MethodsSamples of MLP have been fabricated using 3M Silverluxplastics of different lengths and diameters, in cylindricalforms. The MLPs were exposed at the entrance to the lightgenerated from the quartz tungsten halogen lamp at variousincident angles. The emerging light at the exit was directedto the optical spectrograph consisting of a diffraction gratingand a photodiode array detector (PAD). The transmissionspectrum of the light in the range from 430 nm to 750 nmwas measured for different incident angles and aspect ratios.Results and DiscussionObservation of the measured transmission spectra showedthat the transmission of light decreased with incident angleand the aspect ratio. On average, the transmission reducedfrom about 5% to 90% at the incident angles of 30 and 180res?C~tively. The spectrum decreased gradually as the aspectrano Increased as to be expected, since light interacts andbounces with more frequency at the reflective wall. The de-crease. in th~ trans~ssion spectrum was due to the multipler:flectIons I~ th.e pipe that increase with the length of thepipe and the incident angle of the incoming radiation. How-ever, the result showed that, the incident angle was the domi-n.ant factor in the reduction of the intensity of the transmis-sion spectrum, as compared to the pipe length. Detailedstudy is still needed to verify qualitative these two factors aswell as some other factors such as the reflectivity and theuniformity of the inner wall that may also affect the trans-mission of the light pipes.ConclusionsMirror light p~pes with different aspect ratios can be easilyconstructed USIng commercially available reflective plastics.Light transmission spectra through these MLPs have beenmeasured by using PAD to determine the transmission inten-sity at various wavelengths. The transmission spectra wereutilised to study the characteristics of solar radiation passingthrough the light pipes for day lighting applications.Supported by [RPA Grant 09-02-04-0016185

Transmission of optical solar radiation

http://psasir.upm.edu.my/42340/1/Transmission%20of%20optical%20solar%20radiation.pdf

Transmission of optical solar radiation

Abstract

Similar works

Full text

Available Versions

Universiti Putra Malaysia Institutional Repository