Included in this category are all types of lamps and fixtures; auxiliaries such as ballasts, photocells and dimmers; mounting hardware; and all types of emergency lighting.
Lighting is the most visible aspect of any new construction or renovation project, be it commercial, industrial, or institutional. Even residential projects have focused on the use of lighting to create a very specific atmosphere of warmth and coziness. As such, it receives the immediate attention of the end user. Along with improved variations on standard constructions, lighting fixtures now have new technology lamps that conserve energy while extending lamp life.
High-intensity-discharge (HID) lamps are widely used for both interior and outdoor locations because of their relatively high efficacy (lumens per watt) and small size, thus making them ideal for a variety of fixture types. These sources include mercury vapor (MV), metal-halide (M-H), and high pressure sodium (HPS).
The M-H lamp is considered to have the best color rendition characteristics of the HID family, and an acceptable lamp life from l0,000 to 20,000 furs. This source is available in a large variety of wattage ratings from 70 to over 1000W, in single-and double-ended bulb configurations.
The HPS lamp is regarded as one of the most economical light source in applications where good color rendition is not an important factor. This type of lamp has a 24,000-hr life rating in many of the wattage sizes. In addition, it has a universal burning position, excellent lumen maintenance (90% mean lumens over the life of the lamp), and an efficacy of up to 140 lumens per watt.
Recent fluorescent lamp developments have involved improvements in color rendering through new phosphor coatings and refinements in light output and depreciation characteristics. Reduced-wattage versions are available for the most popular sizes and wattage ratings. Recently introduced T8 and T10 bulb sizes feature excellent color rendition characteristics, high efficacy, and long operating life.
Compact fluorescent lamps in a variety of wattage ratings can serve as economical substitutes for standard incandescent lamps m a variety of interior and exterior applications. In addition, newly designed fluorescent lamps, with twin-tube T5 bulb configuration joined to form a U-shape, are available in many wattage ratings and lengths.
Various lighting fixtures
Incandescent, HID, and fluorescent fixtures for indoor use offer a wide choice of lenses, louvers, and operating modes. Recessed or surface-mounted units are available. Reflectors are formed of aluminum (specular, diffuse, pebbled, etc.) or steel (painted or enameled). Refractors and diffusers are made of glass or plastic, either prismatic or flat, with the material being either transparent, or translucent for obscuring the lamp.
Exterior flood/area lighting equipment can have the lamps exposed or enclosed with a lens. Polycarbonate is a popular lens material because it can be precisely fabricated with integral hinges and latches, and because it is more resistant to impact and damage than glass or acrylic. Polycarbonate can also withstand heat better than acrylic. Refractor designs can provide uniform or nonuniform light distribution patterns in a variety of shapes. Auxiliaries such as stanchions, lowering devices, photocell controls, and other devices also are important components.
Emergency lighting units can be provided as individual wall-mounted units, or by fluorescent emergency packs, which consist of an inverter/charger, batteries, and a switching unit. These items can be incorporated in a fluorescent lighting fixture that is part of the regular lighting layout. Small quartz lamps are sometimes included in HID fixtures to serve during the lamp's restrike period. Exit lights and signs should conform to UL 024, which imposes standards on the performance, life, and visibility provided by these units.