AbstractThisproject involves discovering how the daylighting systems came about. This has been done by examiningevents such as when the Egyptians first developed glass and events led to furtherinventions. Forsome time, there has been the need to bring new technologies utilising daylightin buildings and to assess their performance concerning with the buildingindustry.
This report will provide valuable information regarding the types ofdaylighting systems and its benefits. 1. SummaryTheillumination requirements of an architectural space are the psychologicalbenefits and the energy savings benefits of daylighting system. Daylighting is the practice of placing windows or other openings and reflective surfaces so that during the day naturallight provides effective internal lighting. Particular attention is given todaylighting while designing a building when the aim is to maximize visualcomfort or to reduce energy use. Byproviding a direct link to the dynamic and perpetually evolving patterns ofoutdoor illumination, has been shown to improve the overallattitude, satisfaction and well-being of building occupants, while reducing as much as one-third oftotal building energy costs. In addition, with proper solar control,solar gains during cooling load periods can be mitigated and solar gains duringheating load periods can be utilized, reducing the energy requirements of bothcooling and heating a space.
2. IntroductionThe history of daylightingsystems came about when theEgyptians first developed glass asearly as 3000 BCE, but it was not used to fill an opening in a building untilmuch later, during the first century BCE in Imperial Rome, when small panes ofglass were used to simultaneously admit the warmth of sunlight indoors whileprotecting building occupants from the element of sunlight. Daylightwas the only efficient light available as a primary sourceof daylighting in buildings and the architecture of the day wasdominated by the aspiration to span wide spaces and creating openings largeenough to distribute daylight to building interiors.3. Types of daylighting systemsDaylighting systems is the practice of collecting naturallight and deliver it deep into the buildings with placing windows or other openings and reflective surfaces so that during the daylight provides effectiveinternal lighting.
Attention is given to daylighting whiledesigning a building when the aim is to maximize visual comfort or to reduceenergy use. Energy savings can be achieved from the reduced use of artificial(electric) lighting or from passivesolar heating.Artificial lighting energy use can be reduced by simply installing fewerelectric lights because daylight is present, or by dimming/switching electriclights automatically in response to the presence of daylight, a process knownas daylight harvesting.There are two main types of daylighting system found in Singapore:· Tubulardaylight devices· Mirror-ductsystem· Lightshelf 3.
1 Tubulardaylight device Tubulardaylight devices essentiallyuse a pipe that sticks out of a building’s roof with a highly reflective surface directly into occupied spaces. 3.1.
1. Typicaltubular daylight device · a. Collector: Captures the sunlight · b. Transition: Channel light downwards· c.
Diffuser: Spread light indoor Advantages Disadvantages · No mechanical parts required · Relatively inexpensive · Harvest relatively low levels or light · Consumed small space to install · A significant loss of light beyond 10 metres (3 storey) where there is a change of direction in the tube 3.2 Mirror-duct systemSimilar to tubular daylighting device, the system uses duct madeof highly reflective material (mostly aluminium) to bring in natural light intothe space, enabling a considerable energy natural light into the space and considerableenergy consumption saving. There are no mechanical parts involved and no poweris required for this system.Mirror ducts capture (zenith) angle between the sun andthe vertical. Light is channelled intohorizontal reflective ducts within the false ceiling which then exits throughthe ceiling apertures. c. Illuminating unit The systemcontributes to CO2 discharge reduction by decreasing electric power usage forlighting as well as the creation of comfortable environments that artificiallighting cannot provide. b.
Light-transmitting unit a. Light-capturing unit a. Light-capturing unit: The mirror reflects the sunlightinwardb.
Light-transmitting unit: The”duct” transmit the sunlightc. Illuminating unit: Uniformity in illumination Advantages Disadvantages · High energy efficiency · Transmission of natural light · Energy conservation · A significant loss of light beyond 10 metres (3 storey) where there is a change of direction in the tube 3.3 Lightshelf A light shelf is a passive architectural device that permits daylight toenter deep into a building with its highly reflective surfaces. This can help to reduce the useof artificial lighting at daytime. Light shelves may also function as sunshades. Light shelfs No light shelfs B A 3.2.
1 Different amount of light enter with or without light shelf · A: Glare and focus on one direction· B: Light bounce, avoiding glare and spread lightinto the room Advantages Disadvantages · Enhances daylight quality · Conserves energy by allowing perimeter lighting to be dimmed or turned off · Increases occupant comfort and productivity · Requires higher than average floor-to-ceiling height to be effective (e.g. 3 m) · Increases maintenance requirements · Window coverings must be coordinated with light shelf design 4.ConclusionTheperformance of daylighting system is optimised when it is properly utilised by installingat appropriate places on a building. Its redirection and selectivity of sunrays offers significant amount of energy savings for building owners makingsunlighting strategies more effective in countries like Singapore. These will changethe perspective of building owners of the benefits of installing this daylightingsystem according to their needs and secure a huge cost saving plan in a long run.
5.RecommendationsForeach space in a building, consider whether daylighting is appropriate. Thesetypes of spaces would ideally be located in the core of the building wherethere is limited access to daylight. Spaces that are continually occupied andwhere daylighting would more beneficial to the occupants and to the energyefficiency of the space should have a high daylighting priority. These spacesshould be located towards the perimeter of a building where there is aplentiful daylight resource.