Hatzel & Buehler retrofit over 52,000 fixtures from existing F32-T8 lamps and ballasts to a more energy efficient FO28/28w lamp and electronic low power ballast. LED 12watt lamps will also be installed in all mechanical and open space rooms, along with sensors tied into the HVAC system. As such, when the sensor shuts off, the HVAC will go unoccupied in that area.