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INTRODUCTION AND LITERATURER SURVEY
INTRODUCTION
In IITD campus there are significant numbers of electrical gazettes like lights, fans, refrigerators and ACs in the residential area and those consume a significant amount of power for their operation. This study facilitates to determine such gazettes and to quantify the energy saving. Electricity is a matter of application and as our country is in electricity crises, a significant amount of energy can be saved by using more energy efficient appliances. Nowadays, there are many energy efficient appliances like lights, fans, Refrigerator and ACs that are available in the market so that one can replace the old appliances by new ones and save electricity. Presently in the residential area it is seen that T12 and T8 tube lights are used. These lights may be replaced by T5 tube light and incandescent lamps are replaced by CFL lamps. Similarly, refrigerators and ACs may also be replaced by energy efficient five star refrigerators and ACs.
STANDARDS AND LABELING PROGRAMME
The Objectives of Standards & Labeling Program is to provide the consumer an informed choice about the energy saving, and thereby the cost saving potential of the marketed household and other equipment. This is expected to impact the energy savings in the medium and long run while at the same time it will position domestic industry to compete in such markets where norms for energy efficiency are mandatory. The scheme was launched by the Hon'ble Minister of Power in May, 2006 and is currently invoked for appliances like refrigerator, Tubular Fluorescent Lamps, Room Air Conditioners, Direct Cool Refrigerator, Distribution Transformer, Induction Motors, Pump Sets, Ceiling Fans, LPG, Electric Geysers and Colour TV(9).
Energy labeling program is mandatory from January 2010 for the following products.
• Frost Free Refrigerators
• Room Air conditioners
• Tubular Fluorescent Lamps
The program is in voluntary adoption phase for following products.
• Direct Cool Refrigerators
• General Purpose Industrial Motors
• Open well Pump Sets
• Ceiling Fans
• Colour Televisions
LIGHT SOURCES
INCANDESCENT LAMPS
The oldest electrical lighting technology is the incandescent lamp. Incandescent lamps are also the least efficacious (means lowest lumens per watt) and have shortest life period. They produce light by passing current through a tungsten filament causing it to become hot and hence glow. As the tungsten emits light, it gradually evaporates, eventually causing the filament to break. When this happens, the lamp is said to be “burned out”. In these lamps, light is produced by the electric heating of tungsten filament to such a high temperature that radiation in the visible region of the light spectrum is emitted. General lighting services (GLS) lamps form the mainstay of incandescent lamps. The bulb is either clear, fronted or opal and wattage varies from 15 Watt to 200 Watts, with the great majority lying between shorter life span (between 750 hours to 1000 hours) and are not very efficient. The luminous efficacy defined as the light output (in lumens) divided by wattage and considered as a measure of lamp efficacy generally varies between 8 and 21.5 lumen/W.Higher wattage lamps tend to have better efficacy. Generally average value taken as 15 lumen/W. Light emitted by these lamps is warm (colour temperature around 2800 K) and its colour rendering ability, with its CRI (Colour Rendition Index) as 100 %, is second to none. The basic difference between a GLS and a tungsten halogen lamp is that of a halogen which is added to the normal gas filling and work on the principle of halogen regenerative cycle to prevent blackening. Tungsten halogen lamps are characterized by high bulb temperature, smaller size, and luminous efficacy around 10% more than the normal incandescent lamps (4).
FLUORESCENT LAMPS
Fluorescent lamp work on a different theory, different from that of incandescent lamps. The light is emitted on the basis of discharge through a gas. So no heat is lost in heating a substance to very high temperature where it starts giving out light. Lumen efficacy of the lamp is high as compared to that of incandescent lamp, it is about 60-80 lumen/W.In our houses we are using linear fluorescent lamps whose length is about four feet. These linear lamp are characterize by the diameter of the tube such that as T12, T8 and T5. T12 tube implies a diameter of 1.5 inches and T5 tube implies a diameter of about half inch.
A compact fluorescent lamp (CFL), which can replace an incandescent lamp directly. Many CFLs are designed to replace an incandescent lamp and can fit into most existing light fixtures formerly used for incandescent. Compared to general service incandescent lamps giving the same amount of visible light, CFLs use less power. There are two types of CFLs: integrated and non-integrated lamps. Integrated lamps combine a tube, an electronic ballast and either an Edison screw or a bayonet fitting in a single unit. These lamps allow consumers to replace incandescent lamps easily with CFLs. Integrated CFLs work well in many standard incandescent light fixtures, reducing the cost of converting to fluorescent (3). Non-integrated CFLs have the ballast permanently installed in the luminaire, and only the lamp bulb is usually changed at its end of life. Since the ballasts are placed in the light fixture they are larger and last longer compared to the integrated ones, and they don't need to be replaced when the bulb reaches its end-of-life. Non-integrated CFL housings can be both more expensive and sophisticated (2).
EFFICACY AND EFFICIENCY
Because the eye's sensitivity changes with the wavelength, the output of lamps is commonly measured in lumens, a measure of the power of light perceived by the human eye. The luminous efficacy of lamps refers to the number of lumens produced for each watt of electrical power used. A theoretically 100% efficient electric light source producing light only at the wavelength the human eye is most sensitive to would produce 680 lumens per Watt. The typical luminous efficacy of CFL lamps is 60 to 72 lumens per Watt, and that of normal domestic incandescent lamps is 13 to 18 lm/W (7).