LED Light Distribution Patterns: Types III, IV, and V

One of the top benefits of LED lighting is the ability to direct light uniformly, where it is needed most, without overspill. Understanding light distribution patterns is key in choosing the best LED fixtures for a given application; reducing the number of lights required, and consequently, the electrical load, energy consumption costs, and labor costs.

Light distribution patterns reference the spatial distribution of the light as it exits the fixture. Every lighting fixture will have a different pattern depending on the design, material selection, placement of the LEDs, and other defining characteristics. To simplify, the lighting industry groups the fixture’s pattern into several already classified and accepted patterns.  The IESNA (Illuminating Engineering Society of North America) classifies roadway, low and high bay, task, and area lights into five major patterns.

LED Light Distribution Patterns: Types III, IV, and V

“Distribution Type” refers to how far forward the effective output reaches from the output source. IESNA uses five main types of light distribution patterns ranging from Type I to Type V.  For commercial and industrial use, you will typically see Type III, and Type V.

Type III is our most popular beam distribution and is used to provide a larger area of lighting from a position along the perimeter of where the lighting is required. It is more of an oval pattern with some backlight while also being designed to push the light forward from its source. You typically see Type III patterns on a wall or pole mount pushing the light forward. Type III offers a wider 40-degree preferred lateral distribution width from one forward projecting light source. With a wider flood pattern, this distribution type is meant for side, or near side mounting. It best applies to medium-width roadways and general parking areas.

Type IV distribution provides a flood pattern of 60 degrees lateral width. The semicircular light pattern can be used for illuminating perimeters and mounting on the sides of buildings and walls. Provides forward lighting with minimal back lighting.

Type V provides a circular pattern-umbrella effect. This design is used in general work or task areas where you need light in all directions. This type has an even, circular 360º symmetry of candlepower at all lateral angles, and is ideal for center roadway and intersection mounting. It provides efficient illumination all the way around the fixture.

Overall, these different light distribution patterns are designed to help you get the optimal amount of light exactly where you need it the most.   By specifying the correct pattern, you can reduce the wattage size of fixture, reduce the number of fixtures needed, and ensure you are meeting all your lighting requirements. At Revolve LED, we offer a wide selection of top rated, quality LED Area Lights to meet even your most demanding lighting requirements. We’re here to assist you with lighting layouts and selection. Give us a call today at: 877-718-0808.

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