The Project consists of furnishing all materials, labor, equipment, tools, etc. unless otherwise specified, for the complete and operable installation of: Project consists of demolishing an existing rooftop air handling unit and duct heater and select ductwork at Digesters No. 3 and No. 4, providing a replacement rooftop air handling unit and duct heater with new and modified ductwork, providing multiple exhaust fans for adjacent stairwells, electrical work to support new equipment, installing duct smoke detectors with an allowance for controls integration, replacing existing doors with fire rated doors, demolishing and replacing the roof of the digester building and stairwells, and all associated appurtenances as described in the Specifications and as shown on the Drawings.