Daylight Transmission and Illumination Performance of Optical Fiber Daylighting System

There is normally an excess of daylight outdoors in comparison with what is required at most work places or homes indoors in Malaysia, a country with a hot and humid climate. This excess of daylight can be harvested, concentrated and distributed indoors by optical fibers in replacement of the electrical lighting that is currently in use to reduce building electrical demand while improving occupant comfort by substituting natural sunlight for electric light. Windows and skylights can be used with rooms adjacent to roofs or exterior walls, but they are not an option for rooms far from the building structures. Unconventional daylighting systems using light pipes or glass fiber optics to channel light captured with sun-tracking mirrors or lenses circumvent these problems, but they have proven expensive. This paper reports on an investigation on the feasibility to utilize large diameter optical fiber with one of its ends shaped and polished to a dome-shaped passive collector to gather, convey and distribute solar light passively throughout a scale model of a residential house. The illumination performance of solid core polymer optical fibers for daylight transmission and daylight distribution performance of the endpiece luminaries in the scale model are also presented. An analysis of the illumination performance show that larger diameters of 14 mm and 20 mm solid core endlight optical fibers are more suitable and should be fitted with larger, more efficient diffusers for room illumination.