Title of article :
Light transmission efficiency of daylight guidance systems:
An assessment approach based on simulations and measurements
in a sun/sky simulator
Author/Authors :
Valerio R.M. Lo Verso ?، نويسنده , , Anna Pellegrino، نويسنده , , Valentina Serra، نويسنده ,
Issue Information :
ماهنامه با شماره پیاپی سال 2011
Abstract :
New and more advanced guidance systems are nowadays available, allowing bringing natural light into buildings and offering potentials
for energy savings associated to well-being for occupants. From a design point of view, the key factor is the knowledge of their
photometric performances in terms of global light transmission efficiency, so as to predict the daylight availability in an interior space
due to an array of guidance systems (or, the other way around, to predict the number of pipes needed to produce a minimum natural
light illuminance according to standard requirement) through known analytical methods such as the lumen method. In spite of this,
determining the global light transmission efficiency of advanced guidance systems is a quite complicate matter because of the redirecting
optical properties these elements rely on even in the case of simple typologies (for instance, passive domes with micro-prismatic profiles
and micro-prismatic or holographic films used as pipe’s coating).
This paper presents an approach to characterize photometric performances of tubular daylight guidance systems in terms of light
transmission efficiency: the global system efficiency is the result of the product of the efficiencies of the three individual components (collector,
pipe and diffuser) and each efficiency is determined as the ratio of the flux emitted through the output window to the flux hitting
the input window, accounting for both the beam and the diffuse efficiency. The approach, based on both measurements on physical models
and simulations, was applied to different typologies of pipes and passive collectors and the obtained data were used to eventually
calculate the global efficiency for the analyzed system.
2011 Elsevier Ltd. All rights reserved.
Keywords :
Tubular daylight guidance systems , Light transmission efficiency , Suns/sky simulators , SkyVision
Journal title :
Solar Energy
Journal title :
Solar Energy