As the name implies, troffers are trough-shaped recessed ceiling fixtures (the term is derived from the terms "trough" and "coffer." They usually contain fluorescent lamps and have an open surface flush with the ceiling. A parabolic troffer refers to a recessed fixture that has a louver with a parabolic cross section. The parabolic shape redirects light rays from the light source into parallel rays that shine in a controlled fashion into the room.
A long, recessed luminaire usually installed with the opening flush with the ceiling.
Recessed fluorescent fixture for use in a suspended ceiling; derived from the words "trough" and "coffer."
A long, recessed lighting unit, usually installed in an opening in the ceiling.
An inverted, usually metal, trough suspended from a ceiling as a fixture for fluorescent lighting tubes.
A recessed luminaire that is installed in the plenum with the opening flush with the ceiling. Typically rectangular or square in shape, as in a 2-foot by 4-foot luminaire.
A light fixture, especially a standard recessed fluorescent fixture in a suspended ceiling.
The term used to refer to a recessed fluorescent light fixture (combination of trough and coffer).