Ballast Efficacy Factor (BEF)

Ballast Factor is measured by a certain bulb ballast to produce light from the bulbs it operates. BF is determined by dividing the lumen output of the bulb ballast combination by the total lumen output of the same light bulbs on a reference ballast. Ballast Factor is a whole number that is divided by the input watts.  This is used to measure the level of efficiency of two different ballast. For example, if a ballast has a BEF of .90 and the input watts are 59 (BEF=90/59= 1.53) and is more efficient than a ballast with a BEF of 1.32.