As we all know, daylight is a natural resource that is not going to run out in the future. But what is daylight exactly? And what is the difference between sunlight and daylight? The answer is daylight indicates the extent of diffused natural light from the surrounding sky or reflected off adjacent surfaces, whereas sunlight, on the other hand, refers to the direct sunshine that is very much brighter than ambient daylight. The Picture 1.1 below further illustrates the difference between sunlight and daylight.
Picture 1.1 The difference between a space with sunlight(left) and daylight(right)
For architecture, sunlight is not a very reliable light source that can be used inside a building since the intensity of sunlight makes it a significant source of glare when reflected off a computer screen or falling on a work surface. However, daylight can be a very effective light source. One of the many reasons is daylight is the only light source that will not distort our color judgments, which means it is healthy to human beings no matter physically or psychologically. Another important reason is artificial lighting energy use can be reduced since the increase of use of daylight as lighting source. So it saves energy, and it is also environmentally friendly as no carbon dioxide is produces and no pollution is caused.
Therefore, various daylighting systems were designed wisely by different intelligent people. They combined the art of building design with the natural resource of sunlight to illuminate building interiors, and thus providing a better environment for human beings to carry out all kinds of interior activities.
2. History of Daylighting Systems
With the rise of the problems of environment and energy, people are paying more attention to daylighting systems nowadays for modern constructions. However, way before that, people from ancient times had already known the methods of using daylight as a lighting source. They simply used windows and doors to let the natural light come into the house. This way to use daylight is now called the Passive Daylighting Systems, which means using immobile parts and being able to transfer daylight into a space. This kind of daylighting is often determined by the given location of the sun during the day. One good example is the Pantheon in Rome. The Picture...