Lighting

Electric fitting must be safe and ensure proper safety to the occupants of the house. Low quality products or appliances can cause fatal accidents like short circuit fire/smoke, break out of fire in entire house, current-shock to any member etc. There is proper electric fitting with lighting fixtures which give lighting of different intensity. Every lighting fixture has some advantages over the other. The following are given various lighting fixtures and proper fixation of fixtures.

Lighting or illumination is the deliberate use of light to achieve a practical or aesthetic effect. Lighting includes the use of both artificial light sources like lamps and light fixtures, as well as natural illumination by capturing daylight. Day lighting (using windows, skylights, or light shelves) is sometimes used as the main source of light during daytime in buildings. This can save energy in place of using artificial lighting, which represents a major component of energy consumption in buildings. Proper lighting can enhance task performance, improve the appearance of an area, or have positive psychological effects on occupants.

Indoor lighting is usually accomplished using light fixtures, and is a key part of interior design. Lighting can also be an intrinsic component of landscape projects.

Lighting Types

There are three types of lighting: ambient, task and accent lighting. Ambient, or general, light illuminates the entire room. This basic form of lighting replaces sunlight and is fundamental to a lighting plan.

Task lighting provides illumination for specific tasks, such as cooking or reading. Task lighting should be free of distracting glare and shadows and should be bright enough to prevent eyestrain. Accent lighting highlights specific features of a room, such as cabinets, ceiling beams or artwork. It can create visual interest in a room by highlighting architectural features, such as a mantel or the texture of a wall. All three types of light can work together to fulfill the lighting needs of a room.

Let’s take the dining room, for example. The most obvious purpose of the dining room is to eat, right? But the table also may serve as a desk space for your children to do their homework. And if you entertain, you’ll want to set the lighting mood differently. A traditional chandelier usually works best for general light with recessed down lights providing more targeted light for specific tasks, such as homework. Wall sconces or wall washers can provide a subtler feel. Another option is to set any or all of the fixtures in a room on a dimmer switch so that you can easily control the amount of light in the room.

Key Terms:

• Watt (abbreviated W) is the unit corresponding to the rate of energy consumption (or power) in an electric circuit needed in this case to light a light bulb.
• Lumens are the unit describing the amount of light (energy) as seen by the human eye that is given off by the light bulb.
• Lux is defined as being equivalent to one lumen spread over an area of one square meter. To put it another way, a measurement of lux (light intensity) tells you how many lumens are needed for the area being illuminated.
• Efficiency is the amount of light that comes out of a light bulb compared to the electrical energy that goes into it. Energy efficient bulbs waste less energy in producing light than less efficient bulbs. Efficiency is an output over an input.
• Efficacy is related to the efficiency of the light bulb. It is also an output over an input. The output is the lumens of light and the input in power in watts. So, the expression we use to describe the efficacy of our light is “Lumens Per Watt” or lumens divided by watts. Keep in mind, the bigger the efficacy, the more efficient the bulb.

Lighting Fixtures

Lighting fixtures come in a wide variety of styles for various functions. The most important functions are as a holder for the light source, to provide directed light and to avoid visual glare. Some are very plain and functional, while some are pieces of art in themselves. Nearly any material can be used, so long as it can tolerate the excess heat and is in keeping with safety codes.

An important property of light fixtures is the luminous efficacy or wall-plug efficiency, meaning the amount of usable light emanating from the fixture per used energy, usually measured in lumen per watt. A fixture using replaceable light sources can also have its efficiency quoted as the percentage of light passed from the “bulb” to the surroundings. The more transparent the lighting fixture is, the higher efficacy. Shading the light will normally decrease efficacy but increase the directionality and the visual comfort probability.

Color temperature for white light sources also affects their use for certain applications. The color temperature of a white light source is the temperature in Kelvin of a theoretical black body emitter that most closely matches the spectral characteristics of the lamp. An incandescent bulb has a color temperature around 2800 to 3000 Kelvin; daylight is around 6400 Kelvin. Lower color temperature lamps have relatively more energy in the yellow and red part of the visible spectrum, while high color temperatures correspond to lamps with more of a blue-white appearance. For critical inspection or color matching tasks, or for retail displays of food and clothing, the color temperature of the lamps will be selected for the best overall lighting effect.

Fixture Types

Free-standing or portable Fixtures – such as Table lamp fixtures, standard lamp fixtures, and office task light luminaires.

Fixed Fixtures

• Recessed light : the protective housing is concealed behind a ceiling or wall, leaving only the fixture itself exposed. The ceiling-mounted version is often called a downright. Cans, down lighting , uprights placed on the floor, Troffer light (recessed fluorescent lights ), Cove light ( recessed into the ceiling in a long box against a wall), Torch lamp (floor lamp).
• Surface-mounted light : the finished housing is exposed, not flush with surface.
• Pendant light : suspended from the ceiling with a chain or pipe.
• Sconce : provide up or down lights; can be used to illuminate artwork, architectural details; commonly used in hallways or as an alternative to overhead lighting.
• Track lighting fixture: individual fixtures can be positioned anywhere along the track, which provides electric power.
• Under-cabinet light : mounted below kitchen wall cabinets.
• Emergency lighting or exit light : connected to a battery backup or to an electric circuit that has emergency power if the mains power fails.
• High- and low-bay lighting : typically used for general lighting for industrial buildings and often big-box stores.
• Strip lights or industrial lighting : often long lines of fluorescent lamps used in a warehouse or factory.
• Soffit : can be general or a decorative wall-wash, sometimes used to bring out texture on a wall, though this may also show its defects as well. The effect depends heavily on the exact type of lighting source used.

Indoor Lighting

One of the most common indoor light bulbs are incandescent bulbs, which look like a traditional light bulb. Generally, the input for these bulbs is either 40W or 60W. But there are other kinds of indoor light bulbs as well, such as CFLs and LEDs. Keep in mind that the wattages listed for the CFLs and LEDs correspond to the 40W and 60W incandescent bulbs. This means that for a lamp that takes a 40W incandescent, you could also use a 9W CFL or a 6W LED. This will allow you to easily compare the bulbs to one another.

• Incandescent Bulbs: The incandescent light bulb has had the same design for over 100 years since Thomas Edison invented it! It produces light when a thin wire called a tungsten filament is heated by electricity running through it making it so hot that it starts to glow brightly. This releases a lot of heat and the bulbs get hot to the touch, meaning this bulb is very inefficient. Many countries, including the United States, are currently passing legislation banning the sale of these light bulbs because they are so inefficient.
• Compact Fluorescent Light Bulbs (CFL) : These spiraled light bulbs are far more efficient than the standard incandescent bulb. Compact Fluorescent Light bulbs (CFLs) work by running electricity through gas inside the coils, exciting that gas, and producing light. There is a coating on the spirals, which makes this light white. These bulbs do not get nearly as hot as the incandescent bulbs.
• Light Emitting Diode (LED): Unlike incandescent and CFL bulbs, LED bulbs have moved into the technological age. LEDs that produce white light work in a rather complicated way, and their invention won a Nobel Prize in Physics in 2014! While these are the most efficient bulbs to date, they are not without problems. Although the light they produce looks white, remember that white light contains all the colors of the rainbow. LEDs contain a lot of blue light, too much of which can have negative effects on human health and wildlife.

Outdoor Lighting

Outdoor lights are usually different from those bulbs used indoors because they need to be much brighter and last longer. There are many different kinds of light bulbs used outdoors, and they each have pros and cons.

• Halogen Bulbs: Halogen bulbs are often found in homes as spotlights or floodlights, in cars as headlights, or at sports fields as stadium lights. These bulbs work in a similar way to an incandescent bulb by running electricity through a tungsten filament. Unlike the incandescent, there is halogen gas inside the bulb. When the tungsten burns off
• the filament, the gas re-deposits it back onto the filament to be reused. Halogen bulbs last much longer than incandescent, but these bulbs are much brighter and burn
• much hotter than traditional incandescent bulbs.
• Metal Halide: Metal halide lamps are commonly used in streetlights, parking lot lights, and stadium lights. They are very bright and contribute to a lot of light pollution. They are fairly efficient. They produce very white light and have good color rendition, meaning that objects under these lights look their true color.
• High Pressure Sodium (HPS): The high pressure sodium lamp (HPS) is the most commonly used street light throughout the world. It produces light by running electricity through a mixture of gases, which produces light. The lamp itself is preferred because it requires little maintenance. These lamps are fairly efficient. They take a while to turn on completely and produce a yellow-orange glow.
• Low Pressure Sodium (LPS): The low pressure sodium (LPS) lamp works similarly to the HPS light. Instead of producing white light (all the colors of the rainbow), LPS lamps produce almost exclusively yellow light. While this light is fairly efficient, it takes several minutes for the bulb to turn on. The light is very yellow-orange. This yellow light makes objects it is illuminating look a different color or gray.
• LED Street Lamps: LED technologies have developed rapidly in recent years and these bulbs are now being integrated into outdoor lighting solutions. While the energy savings are significant, LEDs produce a lot of blue light, too much of which can have negative effects on human health and wildlife.

Other Lighting Fixture

• GLS Lamp (General Lighting Serving Lamp): This type of lamps is used inside the building because it has less brightness. Therefore these lamps are not used outside the building and in street lightening. The lamps are available in 25 watts, 40 watts, 60 watts, and 100 watts in the market. These lamps consume more electricity and were used in old days, now these are replaced by fluorescent tube light and CFL (Compact Fluorescent Lamp) which consume less electricity and provide more illumination.
• Fluorescent Tube Light: It is a lamp that produces much light through conversion of ultraviolet energy from low pressure mercury. The lamp consists of a glass tube containing two electrodes, a coating of activated and powdered phosphors and small amounts of mercury. These are available in 10, 20 and 40 watts and in various lengths such as 1 foot, 2 feet, 4 feet. This tube light has multipurpose use as it can be used inside the building and in street lightening.
• Mercury Vapor Lamp: It gives white light and is normally used for street lights. These are available in 80 and 250 watts.

Lighting Maintenance

Having an effective lighting maintenance schedule can include many things including scheduling, policies, and inventory control. Your business should practice basic maintenance strategies between professional visits including:

• Cleaning dust off fixtures, lamps, and lenses every 6 to 24 months. Tip: Never clean an incandescent bulb while it is turned on. If the cloth is damp, the cooling effect of the liquid may shatter the hot bulb.
• Replace lenses if they appear yellow.
• Clean or repaint small rooms every year and larger rooms every 2-3 years because the dirt collected on these surfaces could reduce the amount of light they reflect.
• Consider group light replacement. Common lamps lose up to 30 percent of light output over their service life. Replacing all the lamps in a lighting system at the same time saves labor, keeps illumination high, and avoids stressing ballasts with dying lamps.

Lighting Maintenance Policies

A lighting maintenance policy is a set of written procedures designed to serve as a guideline, not only for everyday maintenance practices, but for optimizing lighting systems on a year-round basis.

Elements of an effective maintenance policy include:

• Blueprints of the facility
• Fixture and lighting controls schedule
• Equipment and service provider sources and contacts, including utility contacts
• Fixture cleaning and relamping schedule with service tracking log
• Procedures for relamping, reballasting, and cleaning fixtures
• Procedures for the adjustment of controls and occupancy sensors
• An overview of proper lamp and ballast disposal

Replacing Lights and Fixtures

Replacing lights and fixtures is an essential part of lighting system maintenance. There are two types of replacement: spot and group replacement. Spot replacement is replacing lamps as they burn out, and is the most commonly used technique in traditional maintenance programs. Group replacement is replacing a set of lamps all at once.