BST211 Environmental Technology II PDF

BST211 ENVIRONMENTAL TECHNOLOGY II Prepared by : Sr. Noorazlina Kamarulzaman (RP) Building Surveying Program, Department of Built Environment Studies & Technology, College of Built Environment (UiTM Perak) TOPIC 1 1.1 Introduction To Lighting AIMS OF THIS CHAPTER Objective of LIGHTING Privacy P...

BST211 ENVIRONMENTAL TECHNOLOGY II Prepared by : Sr. Noorazlina Kamarulzaman (RP) Building Surveying Program, Department of Built Environment Studies & Technology, College of Built Environment (UiTM Perak) TOPIC 1 1.1 Introduction To Lighting AIMS OF THIS CHAPTER Objective of LIGHTING Privacy Privacy is somewhat like being in the shadows. Lighting patterns that are overall low illuminance, non-uniform, and darker in the zone of the occupant than in the surroundings will reinforce on impression of privacy. Illumination purposes To create luminance space in the area for carrying out the activity. Healthy In natural lighting, the light can produce a healthy environment when the proper ventilation is being made i.e. sunrise NATURE OF LIGHT LIGHT IS A KIND OF ELECTROMAGNETIC WAVE. A chart of the electromagnetic wave spectrum is shown in Figure 1. It can be seen that visible light occupies a very narrow band of the whole spectrum. Visible light is a small portion of the electromagnetic spectrum. The energy in the non-visible portions of the spectrum still affects us and must be considered along with the visible portion. In addition to the visible spectrum, the ultraviolet (UV) and infrared (IR) regions of the electromagnetic spectrum are of particular importance to the designer. ELECTROMAGNETIC SPECTRUM  VISIBLE LIGHT REGION LIGHT IS THE ENERGY IN THE FORM OF ELECTROMAGNETIC RADIATION. Light sources typically do not contain all wavelengths in equal intensity throughout the full visible spectrum, although they still appear as “white”. Light with shorter wavelengths and hence higher frequencies have more energy than those with longer wavelengths and hence lower frequencies. Light has specific characteristics at different wavelengths that can be used for different spectral regions. Because of its ability to cause chemical reactions and excite fluorescence in materials, UV light has a large number of useful applications in modern society. Listed below are some of the uses of specific wavelength bands in the UV spectrum: Properties of ELECTROMAGNETIC WAVE The transmissions of light energy can be described as a ‘wave motion’ and can be considered as having the following general properties : 1)The energy resides in fluctuations of electric and magnetic fields, which travel as a transverse wave motion. 5)The waves travel in straight lines but can be affected by : 2)These waves require no medium and can therefore travel through a vacuum. REFLECTION: Reversal of direction which occurs at a surface 3)Different types of electromagnetic radiation have different wavelength frequencies. REFRACTION: Deflection occurs at the boundaries of different 4)All electromagnetic waves have the same velocity, materials. which is approximately 3X108 m/s in a vacuum. DIFFRACTION: Deflection occurs at the edge of objects.  The colors of the visible spectrum as violet, indigo, blue, green, yellow, orange, and red which combination appear as white light. White light = is the effect of the sight of a VISIBLE combination of all the visible wavelengths. RADIATION The wavelength of electromagnetic radiation that is visible to the eye ranges from approximately 30nm to 76nm (1nm is 109 metres). LECTURE 1 INTRODUCTION TO LIGHTING  Non-visible radiation can be described as electromagnetic radiation with wavelengths outside the range of visible wavelength that cannot be detected by the human eye. NON-VISIBLE ULTRAVIOLET LIGHT is not visible, yet it can damage tissue and other organic materials such as furniture and artwork. Therefore, when selecting light sources, the designer should RADIATION consider how much UV radiation will be emitted and absorb the surface. Ultraviolet radiation helps keep the body healthy but excessive amounts can damage the skin and the eyes. It also can be used to kill harmful bacteria in kitchens and in hospitals. INFRARED RADIATION is commonly felt as ‘heat’, or thermal radiation. Light sources often produce infrared radiation along with UV and visible radiation. It also can be used for seeing in the dark and for communication links. THANK YOU