The present paper presents a practical methodology to estimate the round sk
ylight efficiency and hence the amount of daylight that reaches the interio
r of a room equipped with these devices. The methodology is based on flux t
ransfer approach to model the distribution of the luminous energy inside th
e round skylights for various height-to-width ratios, wall reflectances and
transmittances of the glazed cover under diffuse skylight and sunlight. (C
) 2000 Elsevier Science S.A. All rights reserved.