LBNL Report Number
In this paper nine combinations of fluorescent F40 ballast/lamp systems are compared on the basis of initial and operating costs for a new lighting layout using two- and four-lamp fixtures. The factors that influence the input power and light output are studied. Manufacturers tolerance (lamp and ballast), minimum lamp wall temperature, fixture efficacy, ballast and lamp efficacy, and the cost of energy are considered. The ballast/lamp system that is most efficient and provides the greatest light output has the lowest initial cost in a four-lamp fixture. The same system has the lowest operating cost in a two-lamp fixture.