Light Distribution Definition
Patterns projected onto an object or a surface define how light is dispersed from an illumination apparatus. It is determined by the point at which 50% of the fixture’s luminous intensity is met. Indeed, these distributions are an optimal choice for area lighting, roadway lighting, parking lot lighting, etc. Therefore, the industry has created a classification system and recognized five distinct LED distribution types – Type I, Type II, Type III, Type IV, and Type V light distribution. Interested in learning more and knowing how to choose the most suitable and correct distribution pattern from among Type I, Type II, Type III, Type IV, or Type V? Read on to understand in-depth each distribution type and how it applies to the outdoor Area & Site Lighting.
Comparison of Different Light Distribution Types
| Light Distribution | Description |
| Type I | Contributes a wide, symmetrical light and is well-suited for fixtures located in the middle of a walkway. |
| Type II | Renders a slightly wider distribution of light and is ideally intended for light fittings installed at the edge of the roadway. |
| Type III | Casts light about 2.75 times wider than the mounting height of the fixture. |
| Type IV | Popularly known as forwarding throw or asymmetric fixtures, these illuminants shed and scatter light 2.75 times wider than their height, just as Type III. However, they produce a more rounded distribution pattern that pushes the light outward, leaving a faint dim light behind the luminous source. |
| Type V | These omnidirectional fixtures distribute light in a consistent and uniform square or circular pattern around the luminaire. |
Application for Different Light Distribution
Application of Parking Lot Light with Type I Light Pattern
The Type I light distribution is an excellent choice for illuminating walkways, footpaths, and sidewalks. This type of lighting is typically placed adjacent to the center of the pathway, hence providing adequate lighting for narrow pavements.
Type I is a two-way lateral distribution with a preferred lateral width of 15 degrees in the cone of maximum candlepower. The two principal light concentrations are in opposite directions along a roadway. Consequently, this type is generally applicable to a luminaire location near the center of a road where the mounting height is approximately equal to the roadway width.
Additionally, the longitudinal and symmetrical lighting for streets is observed, and the bi-directional illuminance is uniformly distributed across the two sides of the light pole. Therefore, we need relatively lower power to brighten this area and employ LEDs ranging from 30W to 60W.
Application of Parking Lot Light with Type II Light Distribution
Type II light distributions have a preferred lateral width of 25 degrees. They are generally applicable in the case of luminaires located at or near the side of relatively narrow roadways, where the width of the street does not exceed 1.75 times the designed mounting height.
The type II distribution is planted on and near wide walkways, ramps, entrance roadways, and other long, narrow lighting areas thus, illuminating huge and wide spaces. This specific form of lighting is usually set up on constrained side streets, alleyways, and jogging paths.
Application of Parking Lot Light with Type III Light Distribution
The type III distribution designed for illuminating roadways, general parking areas, and other areas require a more extensive lighting area. Type III lighting should be positioned to the side of the road, which allows the light to be projected outward and cover and fills the space, emitting a filling light flow.
Type III light distributions have a preferred lateral width of 40 degrees. This distribution is geared towards luminaires mounted on or adjacent to the side of medium width roadways or areas where the width of the roadway or site does not exceed 2.75 times the mounting height. Lepro parking lot light series with Type III light distribution is apt for installing on one side of a medium-width road or parking lot area.
· Application of Parking Lot Light with Type IV
The Type IV distribution commonly mounted on the sides of buildings and walls generates a semicircular light. It is the perfect choice for illuminating the perimeter of parking areas and businesses, where the magnitude of the Type IV lighting has the same intensity at angles from 90 degrees to 270 degrees.
Type IV light distributions have a preferred lateral width of 60 degrees. This distribution is employed for side-of-road mounting and is frequently utilized on wide roadways, provided its width does not exceed 3.7 times the mounting height.
Furthermore, the power consumption for the Type IV LED pattern is increasingly discerning and demanding. Regardless of the energy requirement, to light up bridges and façades, we have the option of selecting among 100 watts, 200 watts, 300 watts, or up to 400 watts LED lights. Of course, the Lepro LED parking lot lights are a wise choice in this situation.
· Application of Parking Lot Light with Type V Distribution
The Type V light distribution radiates a circular pattern with equal intensity at all angles. This distribution has a circular symmetry of candlepower that is substantially identical and relatively constant at all lateral angles. Supplementarily, Type V distributions deliver the most extensive, even light pattern. Therefore, it is particularly designed for luminaire mounting at or near the center of roadways, center islands of the parkway, and four-way intersections.
Certainly, you may adopt the Lepro LED area Lighting fixtures for large outoor area lighting like parking lots, roadways, playgrounds, stadiums, parks, outside basketball courts, tennis courts and etc..
