Daylighting applications of micro-textured optical surfaces
type: CreativeWork
description: Daylighting is the use of natural light to replace artificial light. In traditional rooms sunlight will only illuminate the area closest to the window due to the high solar angle. The rear of the room appears gloomy and occupants will use electric lighting even though there is sufficient daylight to illuminate the interior. The first section of this thesis reports on the application of micro-prisms to glazing. Such systems could improve the penetration of the light and reduce the energy bill. Fig 1: (Left): A traditional window. (Right) A window with the top third coated in microprisms. The aim of the work is to develop suitable structures than can be easily and cheaply mass produced using an industrial UV embossing process. Whenever possible the requirements of this process dictate the physical characteristics of the microstructures. The development process includes all the stages from design to full-scale testing of the prototypes in an office. Several different mechanical methods are used to produce prismatic arrays that conform to an initial design calculation. Each sample is evaluated in terms of its physical characteristics, its optical properties and finally its ability to improve illumination within a room. The latter aspect is determined, not only by measurement, but also the subjective assessment of occupants. The second micro-textured surface to be examined is the microlens. Three systems are investigated: - A controlled diffuser incorporating cylindrical lenses to improve the distribution of the daylight. - An afocal pair of lenses to improve the penetration of daylight through beam-steering. - An angular filter to exclude direct sunlight while admitting diffuse light. Most of the research is concerned with the third system. On sunny days windows can cause sufficient glare that occupants will pull the venetian blinds. Not only will this exclude the direct sunlight but also the diffuse daylight, cause darkening of the room and leading to the use of artifi…
abstract: Daylighting is the use of natural light to replace artificial light. In traditional rooms sunlight will only illuminate the area closest to the window due to the high solar angle. The rear of the room appears gloomy and occupants will use electric lighting even though there is sufficient daylight to illuminate the interior. The first section of this thesis reports on the application of micro-prisms to glazing. Such systems could improve the penetration of the light and reduce the energy bill. Fig 1: (Left): A traditional window. (Right) A window with the top third coated in microprisms. The aim of the work is to develop suitable structures than can be easily and cheaply mass produced using an industrial UV embossing process. Whenever possible the requirements of this process dictate the physical characteristics of the microstructures. The development process includes all the stages from design to full-scale testing of the prototypes in an office. Several different mechanical methods are used to produce prismatic arrays that conform to an initial design calculation. Each sample is evaluated in terms of its physical characteristics, its optical properties and finally its ability to improve illumination within a room. The latter aspect is determined, not only by measurement, but also the subjective assessment of occupants. The second micro-textured surface to be examined is the microlens. Three systems are investigated: - A controlled diffuser incorporating cylindrical lenses to improve the distribution of the daylight. - An afocal pair of lenses to improve the penetration of daylight through beam-steering. - An angular filter to exclude direct sunlight while admitting diffuse light. Most of the research is concerned with the third system. On sunny days windows can cause sufficient glare that occupants will pull the venetian blinds. Not only will this exclude the direct sunlight but also the diffuse daylight, cause darkening of the room and leading to the use of artifi…
author: Bhatia, Rikki
language: en
keywords: Natural light, Angular filter, Traditional rooms, Micro-prisms glazing, Industrial UV embossing
date published: 2001
date modified: 2026-07-24T01:23:24Z
provider: University of Brunel
publisher: Networked Digital Library of Theses and Dissertations
type: WebPage
source organization: Brunel University School of Engineering and Design PhD Theses