The subject of the present paper is a fixed daylighting system known as the
LIF light guide. The system consists of a fixed arrangement for capturing
sunlight incident at various angles and re-directing it by means of an opti
cal wave-guide which provides diffuse ceiling illumination. The light guide
is generally sandwiched between two glass panes and mounted above the wind
ows to avoid obstructing visibility. Its intended function is to furnish of
fices and other working areas with a uniform level of natural illumination
while avoiding glare. (C) 1999 Elsevier Science Ltd. All rights reserved.