Types of Lighting & General Characteristics

The four basic types of artificial lighting are incandescent, fluorescent, high-intensity discharge, and low-pressure sodium.

Incandescent is the least expensive to buy and the most expensive to operate. It has the shortest life span of the common lighting types and is relatively inefficient compared with other lighting types.

*   Replacing incandescent lamps with compact fluorescent lamps provides energy savings of 60% to 75%. Tungsten halogen bulbs use about 60% less power than standard incandescent and provide longer service. They are considerably more expensive than standard incandescent.

High-Intensity Discharge (HID) lights are similar to incandescent in appearance and compactness with concentrated and directed light output.

*   They are not very energy efficient compared to energy efficient fluorescent, however are the most common light source in industrial and commercial buildings.
*   The use of controls, daylighting, and sensors are not conducive with HID lighting, limiting the ability to save energy.

Fluorescent is an energy efficient lighting choice because it is about four times as efficient as incandescent lighting.

*    Fluorescent lighting is used for both ambient and task lighting.
*    They normally last about 10 times longer than incandescent and 3 times that of HID.

*    Select fluorescent bulbs with electronic ballasts.
*    For compact fluorescent, select a ballast base that is separate from the bulb. The ballast will outlive the bulb, letting you change the bulb only.
*    Select the longest rated life.
*    The efficiency of lights is measured by the amount of lumens created per watt of electricity expended. For example, fluorescent lights may range from 22-85 lumens per watt.
*    The Color Rendering Index (CRI) and Kelvin Temperature should be suggested and explained by your lighting specialist.

LED (Light Emitting Diode) are small, solid light bulbs that are extremely energy efficient. Until recently, LED's have been limited to single bulb use. Manufacturers have expanded the application by clustering the small bulbs. This opens the door to many energy efficient retrofits/replacements. LED's are on the path to become the next generation of standard lighting.