Shall consist of replacement of existing heating and ventilation systems including air-handling units, exhaust fans, ductwork and controls. Related work to include furnishing and installation of new package rooftop heating and cooling units, ductwork and controls, new ductless split air conditioning systems and controls, as well as new electrical to the rooftop units and structural supports for new rooftop units with the removal and reinstallation of ceiling tiles and grid as well as replacement of ceiling tiles.