The illumination of the environment undergoes both intensity and spectral changes during the 24 h cycle of a day. Daylight spectral power distributions are well described by low-dimensional models such as the CIE (Commission Internationale de l'Éclairage) daylight model, but the performance of this model in non-daylight regimes is not characterised. We measured downwelling spectral irradiance a...

This paper presents a methodology for optimizing skylight design with the considerations of thermal comfort, daylight availability and energy performance by integrated daylight and thermal simulation. Dynamic thermal modelling programmed IES and daylight simulation engine Radiance are used as simulation tools to study energy performance of a shopping mall atrium with a skylight on the roof ...

Atrium is a popular architectural feature utilized widely by building designers and owners to bring various benefits such as adequate daylight, circulation spaces and surfaces for landscape applications. But atrium problems in tropical climates such as excessive daylight, glare and high temperature, which lead to increase building energy demand, have been reported. Atrium has been used with var...

The research reported here was funded, in part, by the California Institute for Energy Efficiency (CIEE), a research unit of the University of California. Publication of research results does not imply CIEE endorsement of or agreement with these findings, nor that of any CIEE sponsor. This work was also supported by the Assistant Secretary for Energy Efficiency and Renewable Energy, Office of B...

The apparent color of an object within a scene depends on the spectrum of the light illuminating the object. However, recording an object's color independent of the illuminant spectrum is important in many machine vision applications. In this paper the performance of a blackbody-model-based color constancy algorithm that requires four sensors with different spectral responses is investigated un...

EvalDRC is a newly developed daylight analysis tool for the evaluation of Daylight Redirecting Components (DRC) in architectural spaces. It focuses on the accurate simulation of light redirection with help of the lighting software environment RADIANCE. It employs various key technologies, among them are: a) the daylight coefficient method, b) characterisation of the light redirection behaviour ...

Climate-Based Daylight Modelling (CBDM) methods have been validated against long-term measurements in laboratory settings and found to exhibit errors small enough make such assessments useful for daylight performance prediction. However, real occupied spaces are affected by a higher number of uncertainties than or controlled conditions. This study aims at validating CBDM collected an classroom ...

the first step in evaluating the visual performance and energy efficiency provided by daylight, requires an accurate estimation of the amount of daylight entering a building. the atrium concept allows the exploitation of daylight by bringing natural light into the center of the buildings, thus enhancing even a more distribution of daylight. daylight reception through an atrium is particularly b...

To describe complex fenestration systems such as novel solar blinds, new glazing or coating materials, daylight and sunlight-redirecting devices, a detailed description of their optical properties is needed, given by their Bidirectional Transmission (or Reflection) Distribution Functions (commonly named BTDFs and BRDFs). These functions are angle-dependent at both the incidence and the emission...