ENERGY EFFICIENT REPLACEMENTS

For many of the popular lamp types there are energy efficient replacements designed to deliver approximately the same amount of light at reduced wattage. These lamps are generally more expensive than their corresponding standard lamps but the additional cost can be recovered in a few months worth of energy savings.

Choosing The Right Lamp For The Application

Choosing the right lamp for a particular application can save energy and result in the highest quality of light. Unfortunately, in many cases a building manager will choose the cheapest lamp over the most appropriate lamp and the quality of the light is sacrificed.

For example, in a recessed down-lighting fixture the cheapest lamp may be an "A" and "PS" lamp, while a PAR or some type of reflectorized lamp makes more sense. The building manager will have to use a higher wattage "A" lamp in this fixture than a "PAR" or other reflector type lamp. The result is higher energy cost. These added energy costs often outweigh the cost savings in the lamp itself. Therefore, choosing the right lamp for the right application, sometimes costs more up front, but it will save money over the life of the lamp.

Use Higher Wattage Lamp

Some applications call for using multiple lamps in a fixture or using a large number of low wattage fixtures. Incandescent lamp efficiency increases with high wattage lamps. Therefore, using two 75 watt lamps is less efficient than using one 150 watt lamp. When possible, it is better to use higher wattage lamps in fewer quantities.

Note, however, that using fewer lamps may result in a less uniform lighting system. The resulting lighting system may produce hot spots and cold spots at the work place. When considering changes to a lighting system design always make sure that these "quality of light" issues are addressed.

Of all the major light sources, incandescent is the least efficient. This graph illustrates the range of lumens per watt by source. However, despite its low efficiency, incandescent lamps do make sense in many applications, particularly when color and brilliance are important features. In some cases though, efficiency far outweighs the need for good color rendering, brilliance, or ambiance. In these cases other lighting sources can be considered as substitutes for incandescent lighting.

Fluorescent lighting is perhaps the easiest and least expensive alternative to incandescent lighting. Compact fluorescent lamps are available in sizes that are comparable to incandescent lamps. They generally require 1/4 to 1/2 of the wattage of incandescent lamps for the same lumen output and they have much longer lives.

High Intensity Discharge (HID) sources have also been used to replace incandescent lamps. HID sources are considerably more efficient than incandescent sources but they are also much more expensive. HID sources make sense in areas that require very high light intensity.

ER Lamp

An ellipsoidal reflector lamp is specially designed so that the focal point of the light lies several inches below the edge of the lamp. This can be particularly useful in recessed down-lighting fixtures.

The standard flood lamp. 

ER Lamp delivers some light which effectively gets trapped inside the fixture. The ellipsoidal reflector or "ER" lamp projects more light out of the fixture. A 75 watt ER lamp

ER Lamp

Halogen lamps operate more efficiently than standard lamps. Since halogen lamps are available in most of the popular lamp types, they make an excellent choice for lamp replacement.

Halogen lamps are more expensive than standard incandescent lamps. However, the savings in energy far outweigh the additional cost

Tungsten Halogen Lamps

Tungsten halogen lamps are a class of incandescent lamps that are specially designed to burn hotter and brighter. Recall that the light output from an incandescent lamp depends on the temperature of the filament. The hotter the filament becomes...the more energy is released in the form of visible light.

Tungsten halogen (or just "halogen") lamps are designed to be a bulb inside a bulb. The primary bulb or capsule as it is sometimes called enclosed the filament and its fill gas. This capsule is coated with a special film on the inside part of the glass which reflects infrared radiation and allows visible light to pass.

For standard incandescent lamps, almost 90% of the energy consumed by the lamps is released in the form of heat. Some of this heat is actually infrared radiation. The infrared or "IR" coating on the halogen lamp reflects this infrared radiation back onto the filament making it burn hotter and hotter means more and brighter light.

Halogen lamps are also designed to reduce the degenerative process by which tungsten metal evaporates off of the filament wire. In halogen lamps, the evaporated tungsten metal is redirected back to the filament and thus the filament "rebuilds" itself as it burns. This results in a longer rated life for halogen lamps over standard incandescent lamps.

The capsule in the halogen lamp is normally enclosed in an outer bulb. This prevents much of the heat from transferring to the environment while also serving as a safety shield if the halogen capsule ruptures or explodes

Low Voltage Halogen

A special class of tungsten halogen lamps has recently emerged and become very popular especially in retail applications. This is the low voltage halogen. It is characterized as having very high candlepower for a sharply defined and well controlled beam spread.

The low voltage halogen lamps are available primary in the miniature reflector or "MR" designs..

Since they operate at low voltage they do require a special transformer.

These lamps provide a dazzling environment for which to emphasize a product or draw attention to a display. They are also very efficient in that light can be concentrated in one particular area of interest without having to illuminate an entire room or area.

Energy Efficient Incandescent Lamps

Energy efficient incandescent lamps generally have the same design as standard lamps. In most cases the main difference lies in the type and quantity of fill gas used. Most standard incandescent lamps contain a mixture of argon and nitrogen gases. Some energy efficient versions of those same lamps contain Krypton gas which is more rare and therefore more expensive than argon and nitrogen. Krypton gas has a higher atomic weight, reducing the energy loss from conduction and convection in the lamp.

Energy Efficient incandescent lamps use approximately 10% less power than their standard counterparts. Energy efficient incandescent lamps are generally only available for the most popular lamp types. However, there are other ways to achieve energy efficiency when an energy efficient lamp is not available.

Environmental Aspects of INCANDESCENT

Incandescent lamps do not contain any materials that are considered harmful to the environment. Therefore, to date, there are no specific regulations restricting their disposal. However, incandescent lamps do contain materials that can be recycled such as glass and aluminum. New companies are emerging in the United States which can recycle a variety of lamps. They recycle the glass and aluminum and in some cases are able to recover rare fill gases that can be reprocessed and sold back to lamp manufacturers. This is a very new industry so there may not be one of these companies in your area.