Specifications include, but are not limited to: The work under this contract consists of mechanical, electrical and instrumentation work for the replacement of an existing 10 ton Trane Roof Top Unit, RTU, and a 6 ton Carrier RTU. The existing roof curbs will be utilized and the replacement RTUs will have similar capacity as the existing units. This will include, but not limited to, the following: 1. Rigging for removal of the existing single zone packaged rooftop units and accessories, and installation of new single zone packaged 10 ton and 6 ton rooftop units, economizer and accessories. Removal and disposal of existing rooftop units. Reclaim and dispose of existing Freon in RTUs 2. Supply and install new 10and 6 ton package energy recovery rooftop units, RTUs. 3. Selective demolition of natural gas piping to accommodate installation of new single zone packaged rooftop units, cut back piping including existing valve. Prep existing natural gas piping for connection to new natural gas piping. 4. Selective demolition of the existing rooftop units mounted temperature controls and accessories. Existing rooftop unit temperature controls within the building shall remain intact. 5. Selective demolition of supply air discharge ductwork to accommodate installation of new single zone packaged rooftop units. 6. Selective demolition of electrical. Disconnect the existing units electrical circuit. Remove circuiting and associated disconnect switch as needed. Provide new disconnect for each unit and connect power to each unit. 7. Provide curb adapter for installation of new single zone packaged rooftop units on existing roof curb. Length of existing roof curb may differ than that of the new units, curb adapter may be required to cover unused section of existing roof curb. Units shall be installed on same end of existing roof curb as existing. 8. Provide roofing for pitch pockets if necessary. Pitch pockets must not compromise the roof warranty. Contractor must contact the roof manufacturer to insure that the pitch pocket will not violate the roof warranty. 9. Provide supply air ductwork connection and accessories from single zone packaged rooftop units. 10. Connect condensate drain piping for each unit. 11. Extend existing natural gas piping and connect to new single zone packaged rooftop units. Provide new shut off valve at units connection. If gas connections are through bottom of unit, route gas piping through side of existing roof curb. Seal penetration in accordance with roofing manufacturer’s guidelines, to maintain warranty. Provide pipe supports to match existing. 12. Extend existing building temperature control system to perform functions specified herein. 13. Extend existing electric circuit to new units. Provide 3 phase heavy duty fusible NEMA 3R switch fused per the manufacturer's recommendations. 14. Fire Alarm: Disable existing duct mounted smoke detector at the system control panel for the duration of the work. Clean detector and enable utilizing the system at completion. Connect fan shutdown to new unit controls.