Abstract: A high efficiency grid troffer comprises a housing, a grid door cover, and one or more pairs of multifaceted reflector and light emitting unit. The multifaceted reflectors are attached inside the housing. Each multifaceted reflector contains a predetermined number of concave or convex facets. Each facet can be of various shapes and sizes to achieve maximum lighting efficiency and even distribution of light. A light emitting unit is paired with each multifaceted reflector and is also attached to the housing. The grid door cover is attached to the housing to close the high efficiency grid troffer. The grid door cover can be removed from the housing for easy assembly and maintenance.