With LED, form factor is not as relevant as compared with traditional light sources such as Metal Halide (MH), High Pressure Sodium(HPS), and linear fluorescent. What does form factor mean? For years the shape of luminaires were designed to accommodate the size and shape of the lamp(s) and ballast(s). Now as LEDs gain market share, lighting designers are able to design new luminaires using much smaller LED arrays, LED modules and LED chips on board. Since the LED light sources can emit the same light as traditional light sources from a much smaller area, lighting designers are able to achieve the same light output using a smaller fixture and/or a different shape than they would have in the past.
An example of the change in size of the light source, the net effect on the luminaire, and the impact on the end user is a classic grocery store. Until recently, grocery stores used 8’ fluorescent fixtures to illuminate the aisles. The fixture was designed to house one or two 8’ linear fluorescent lamps. Obviously the fixture had be over 8’ long to house the lamps. Designs were either basic with an exposed lamp or lamps, or the same with a plastic diffuser over the lamps. The form factor was also necessary to create a long line of light to properly distribute light and illuminate the aisles.
Now that T12 is virtually extinct and T8 will follow, how are form factors changing? Now, with a 2’ long fixture, it is possible to duplicate the light output and distribution provided by an 8’ fixture. Are the supermarket owners ready to reduce the size? Maybe. Some supermarket managers are using the new 2’ LED luminaires. Others are using a 4’ version while a few are sticking with the 8’ linear form factor.
Why do they choose 8’ LED luminaires when 2’ will do? Some property managers, however, choose to install the larger fixtures to cover the holes in the ceiling from the previous fixtures, or simply because they prefer the traditional look. This also means paying more for a larger fixture that houses the same components as a small fixtures. Those who choose the smaller form factor, cover the holes in the ceiling and pay less for the smaller fixtures that deliver the same results. Regardless of the size of the LED fixture, the same amount of LED chips will be used to illuminate the area.
Form factors are changing for wall packs to. Look for our next blog on LEDs, form factors and wall packs.
Do you have a question about form factor in your lighting project? Contact an Access Fixtures lighting specialist.