Lighting enclosed interior corridors by borrowed daylight.

Enclosed internal corridors are long circulation areas with no window provisions, and they require electric lighting to be switched on for 24 hours continuously to operate. Depending on the designs, some corridor designs have openings for daylight at the ends, while others supplement daylight at the middle. Most parts of these corridors, however, are usually dark and consuming a lot of non-renewable energy from artificial light. This paper explores how enclosed internal corridors could get the benefits of daylight de-pending on the corridor wall designs. It explored how %DF (Daylight Factor) less than 1%, especially in Malaysia where the skies are bright, could still be beneficial and useful. The standard illumination required for corridors is benchmarked. Fieldwork for %DF measurements was taken in selected points at an enclosed corridor of a hostel building on a typical overcast day. A scaled model of similar design was built and experimented in the artificial sky to get the same set of readings; followed by simulation using Radiance. Results showed that the readings calibrate well between fieldwork compared to the scaled model and simulation, with less than 10% differences. Corridor walls are usually opaque resulting in very dark situations relying solely on artificial lighting. The study further investigated the extent of daylight which can be borrowed to light the internal enclosed corridors. This was carried out by experimenting on the various types of corridor wall designs with added transparent or glazed areas to enable daylight penetration. The designs experimented with various horizontal and vertical alternatives. The effects of these new corridor wall design on daylight distribution in corridors are investigated by Radiance simulations. Results were compared to the base case which was the normal. The findings showed that the newer designs of corridor walls could provide daylight to corridors with significant levels of improvements. Even though the %DF found were very low, outdoor illuminance in tropics is high therefore it was sufficient for corridor lighting. Corridors with 50% glazed areas in a 4 strips horizontal design were found to perform the best for allowing borrowed daylight to occur. [ABSTRACT FROM AUTHOR]